Aims: The main goal of this study was to present a reference model for the Health, Safety, Environment and Ergonomic HSEE performance measurement system. Materials And Methods: This study was done in a petrochemical unit in Iran during the year 2009. In first step, the existing information systems and their effect on personals were evaluated. Then the HSEE performance indicators were determined. The number of indicators were 244. After designing and implementing of the continuous monitoring system, the mentioned indicators were measured and controlled, continually. Results: In cases that the indicators showed deviation from defined criteria, corrective actions can be done with forecasting and introducing some suitable techniques for hazard identification and problem solving. With implementation of the integrated performance measuring system unsafe behavior, musculoskeletal disorder and suitability of HSEE committee discussions were improved 12%, 7.3% and 22.6%, respectively. Conclusion: The findings of this study emphasis on the need to conduct further research on the continuous monitoring of mentioned system in future years and performing necessary corrections. To improve the system performance, the continuous correction of indicators and related decision criteria, regular training of personal and implementation of award system are suggested.

Aims: The trihalomethanes (THMs) concentration was investigated in some of rural water treatment plants in Khuzestan. Materials and Methods: Fifteen of the water treatment plants with the same drinking water source (Karoon river) were selected for analysis of THMs to assess the levels and the relationship between THMs and total organic carbon (TOC), pH, temperature, chlorination dose, and free chlorine residue. Results: THMs ranged from 1.8 to 219 mg/l in winter and 1.7 to 98 in summer, where the level in some treatment plants is higher than the Maximum Concentration Level (MCL). The ratio of total THMs levels was significantly correlated with temperature, pH, chlorination dose, and free chlorine residue, but negative correlation with TOC. Conclusion: Epidemiological studies using total THMs levels should be considered in the analysis of water treatment plant's results, and regulatory check of this parameter with drinking water guidelines.

Aims: The main aim of this study was to investigate the relationship between the amount of noise pollution and traffic rates in Khojir National park and regarding that finding a suitable distance for installing fencing according to the standard level of noise pollution. Materials and Methods: Eight stations located exactly above channels have been selected. In each station, three different substations including near the road, 25, and 50 m from the road were chosen. For determining the essentiality of soundproof installation, noise levels were measured at the opening and in the middle of the channel. Traffic rates have been measured daily from 6 AM to 6 PM for two continuous weeks and noise levels were then determined in three different days according to the traffic peak. Results: Results obtained showed a significant relationship between traffic rates and noise levels in near-road stations (R ² linear = 0.341). The relationship between interval and noise level was also significant (R ² quadratic = 0.701, P < 0.05). Furthermore, a distance with 55 dB (A) (i.e., 50 m in this study) was achieved as a proper site for fencing. Conclusion: Although the amount of noise levels in the middle of channels were less than the standard level, this amount in some channel throats were higher and need to be considered for soundproof installation as well. In addition to finding an area for fencing, using solution(s) for reducing either noise pollution or its impact at this area should be taken into consideration.

Aims: This study aims to compare the parameters in filtration unit of the plant with international guidelines. The results of this study would determine the necessity for replacing or renewing the anthracite and sand filter beds in phase I of IWTP. Materials and Methods: In this field study, a total of 11 samples with a mass of 5 kg sand and anthracite media were analyzed. The media samples were evaluated in view of uniformity coefficient and effective size according to international soil classification. Data obtained were statistically analyzed using t-test at significance level (P < 0.05). Results: Results of this study showed that the uniformity coefficients of anthracite and sand media were 3.6 ± 0.4 and 1.93 ± 0.11 mm, respectively. Also, the effective sizes of anthracite and sand media were 0.68 ± 0.08 and 0.63 ± 0.05 mm, respectively. These values exceeded the international guidelines and had a significance difference with them (P-value < 0.05). Conclusion: The results were shown that the uniformity coefficient and effective size of sand and anthracite media in the filters used in phase I of IWTP exceeded the guidelines and they need to be replaced with new media. Finally, based on the current study, filter beds were renewed.

Aims: The aim of this study was the optimization of the SBR system for enhanced biological phosphorus and nitrogen removal. Materials And Methods: A lab-scale SBR consisting filling, pre-anoxic, anerobic, anoxic, aerobic, settling, decanting, and idle phases was proposed for simultaneous enhanced biological phosphorus and nitrogen removal (SEBPNR) from wastewater. Synthetic wastewater was used in this research. Glucose was used as a carbon source. The SBR was seeded with sludge from a local municipal wastewater treatment plant. Results: The results indicates that the lab-scale SBR was capable to remove soluble phosphorus (SP), SCOD, TCOD, and ammonia, with efficiencies of around 92%, 95%, 80%, and 85%, respectively. Optimized lab-scale SBR operational condition for SEBPNR consists of a fill (15 min), pre-anoxic (30 min), anerobic (90 min), 1st aerobic (210 min), 2nd anoxic (55 min), 2nd aerobic (10 min), settling (90 min), decant (10 min), and idle (10 min) phases. Conclusion: This study concludes that effective biological removal of phosphorus and nitrogen from wastewater using SBR occurs in sufficient HRT in the anaerobic and aerobic stages, adequate COD/TP ratios (up to 35). This system is suitable for high removal of P and N in both municipal and industrial wastewater.

Aims: This study was undertaken to determine the microbial quality and the prevalence of Salmonella and Listeria in table eggs in Isfahan, Iran. Materials and Methods: A total of 525 samples were randomly collected from various shops in Isfahan, Iran. Microbial quality of eggs evaluated by coliform count and total bacterial viable counts. Also, detection of Listeria and Salmonella in egg contents and on eggs shells was performed. Results: The mean of total viable bacteria and coliform counts in the egg contents were 3.95 × 10 ⁴ CFU/g and 4.94 × 10 ³ CFU/g, respectively. Salmonella and Listeria were not found on the shell or content of eggs. Enterobacteriaceae families were found in 357 of 525 (68.28%) and 276 of 525 (52.44%) of egg shell and egg content samples, respectively. Moreover, Pseudomonas aeruginosa was isolated from 175 (33.41%) and 144 (25.37%) of egg shell and egg content, respectively. The isolated Enterobacteriaceae were included: Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Buttiauxella agrestis, Cedecea lapagei, Cedecea davisae and Erwinia herbicola. Conclusion: The findings of the present study indicate although Salmonella and Listeria were not found in egg samples; however, there is an urgent need to improve the hygienic level of consumed eggs.

Aims: The aim of this study was to evaluate the bioaerosols level in the various parts of three educational hospitals of Isfahan, Iran. Materials and Methods: The collection of bioaerosols (including bacterial and fungal microorganisms) was carried out with one-stage Anderson sampler. The sampling was carried out at the height of 1.5 m from the floor of various hospitals wards (infectious, surgery, urology wards, and operating room). The volume of each sample was determined based on pre-tests carried and was about 50 L. After sampling, the samples were incubated and analyzed. The effect of various environmental conditions including humidity, temperature, and outdoor bioaerosol levels was also investigated. Results: The lowest numbers of fungal and bacterial concentration were obtained in operating rooms of the hospitals and the highest concentration was observed in infectious disease wards of hospital 1 and 2 and surgery ward of hospital 3. The bacterial concentration was observed to be higher in hospital wards than outdoor, except hospitals' operating rooms. Conclusion: The findings showed that the bioaerosols level in the hospitals was relatively high. The higher levels of indoor bacteria than outdoor might be associated with the presence of patients, their activity, unsuitable ventilation, and disinfection. Therefore, environmental monitoring and control measures are required to improve hospital environmental quality especially in the wards with immune deficiency patients.

Aims: This study was conducted for degradation of 4-chlorophenol by microwave (MW) radiations alone and in combination with hydrogen peroxide from aqueous solution. Materials and Methods: A modified domestic microwave oven was used alone and in combination with hydrogen peroxide for removing 4-chlorophenol. Furthermore, the influences of pH value, irradiation time, the power of MW radiations, and the initial concentration of 4-chlorophenol were studied. Results: It was shown that 4-chlorophenol removal efficiency extremely depend on the concentration of hydrogen peroxide, pH value, MW irradiation power and initial 4-chlorophenol concentration. The optimum conditions obtained for the best degradation rate were pH = 10.5, H ₂ O ₂ concentration of about 0.1 mol/l, and MW irradiation power of about 600 W. Other result shows that the best degradation rate of 4-chlorophenol was obtained when initial 4-chlorophenol concentration was 50 mg/l. Also the amount of the specific energy consumption in this method was 17460 kwh/kg of the removed organic compound. Conclusion: This result shows that MW irradiation in the presence of hydrogen peroxide can greatly enhance the degradation of 4-chlorophenol. However, the high consumption of energy for this method must be taken into consideration.

Aims: In this study, the amount, composition, and energy content of waste in Isfahan, Iran, were examined. Materials and Methods: A time series model was used to predict the amount of waste generation in the future. The past waste changes was the basis for predicting how and to what extent the components will chnage. The energy content of mixed waste was calculated by the common heating value of each component and Dulonge's formula. Results: The estimation of the amount of waste generated in Isfahan showed that the amount of organic materials would reduce to 59.1% and plastic materials would increase to 24.44%. Heating values of mixed waste, coarse, and fine reject based on dry weight were estimated in the first method as 3230, 1911, and 370 MWh per day, respectively, and as 2656, 1160, and 329 MWh per day, respectively, using Dulong's formula for the year 2019. Conclusions: The results showed that by separating the combustible part of the waste and incinerating it, a remarkable amount of energy would be produced from waste in Isfahan resulting in the reduction of required landfill space and greenhouse gas emissions.

Aims: This study was designed to evaluate the validity of urinary 1-hydroxypyrene as a biomarker in carcinogenic PAHs (cPAHs) exposed Iranian carbon anode plant workers. Materials and Methods: The study population consisted of 42 workers working in a carbon anode plant and control group consisted of 43 office workers. Personal air sampling was performed to assess workers atmospheric exposure to carcinogenic PAHs . Urine samples were collected for analysis of urinary 1-hydroxypyrene using high performance liquid chromatography (HPLC). Statistical analysis was performed with SPSS version 16 software. Results: The mean concentration of occupational exposure to cPAHs in the exposed group was 11.42±7.56 ΅g/m ³ . Mean level of urinary 1-hydroxypyrene in the exposed and control groups were 6.32±4.9 and 0.54±.48 ΅mole/mole creatinine, respectively . Urinary level of 1-hydroxypyrene in the exposed group was significantly higher than the control group (P<0.001). A strong and significant correlation between total cPAHs exposure and urinary 1-hydroxypyrene (r=0.79, P<0.001) was found . Conclusion: The results confirm urinary 1-hydroxypyrene level as a good biomarker in cPAHs exposed workers. In addition, considering the level of urinary 1-hydroxypyrene, it can be concluded that studied carbon anode plant workers are exposed to substantial risk of cancer and other genotoxic effects which are the result of cPAHs exposure.

Aims: The aim of this study was the investigation of musculoskeletal disorders risk factors among building demolition workers. Materials and Methods: Posture, activity, tools, and handling (PATH) method as a work sampling method was applied to record the postures, activities, and handling of building demolition workers in four tasks. The percentage of working time is reported for each item to compare the risk factors in tasks. Nordic musculoskeletal questionnaire also was used to study the prevalence of musculoskeletal disorders over 12 months. Results: Trunk, leg(s), and arm(s) postures differed significantly among tasks. Neutral arm posture and non-neutral leg(s) and trunk postures were observed frequently. Manual materials handling (MMH) activities are distributed differently among tasks. Moving was the most observed (35%) and carrying was the less observed (11.8%) MMH activity. Gross grasp was the most observed (78.5%) hand activity in building demolition workers. The most observed weight category was 0 kg≤load<5 kg. Low back had the highest prevalence of MSDs symptoms (91.1%) and hip had the lowest prevalence of symptoms (6.7%). Conclusions: PATH is applicable to building demolition process. Ergonomic intervention is necessary in high prevalence body regions such as lower back and wrist to decrease the symptoms. With respect to the results of PATH method, ergonomic interventions for trunk and leg(s) are necessary in all tasks, but only task #3 is in the priority of arm(s) intervention.

Aims: The aim of this study was to evaluate the performance of photoionization detector (PID) system as a substitution for gas chromatography in the measurement of a 3 xylene isomer mixtures as a representative of the volatile organic compounds in photocatalytic studies. Materials and Methods: This study has been carried out by using test setup for generating known concentrations from equal ratio of 3 xylene isomers. The concentration values to be evaluated were classified into 4 concentration ranges from 0.1 of threshold limit values (TLV) to 2 of TLV to evaluate the PID system appliance compared with that in the reference method. The test was done 4 times for each evaluation concentration in 3 relative humidity levels (0%, 20%, and 80%). Results: The correlation between the PID results and the National Institue of Occupational Safety and Health (NIOSH) reference method results in an atmosphere with relative humidity of 0%, 20%, and 80% were good and, respectively, were 0.993, 0.992, and 0.991 and total correlation was 0.989. The paired t test indicates a significant difference between actual concentrations in reference method and the extracted concentration from PID. Conclusions: Although the results presented by PID in the present study are different from those extracted from the reference method (from 10 to 260 ppm), the equipment response is linear. So, the results are acceptable in photocatalytic studies in case the contaminant concentration is measured by the same equipment either before or after the reactor for calculation of the removal efficiency. PID calibration with the test material(s) is recommended.

Aims: This study aims to simulate dissolved oxygen of Zayandehrood river from regulating dam to Polle-Kalleh bridge using MIKE11 software that is a hydrodynamics and water quality model. Materials and Methods: During 5 months the samples were taken from four hydrometric stations and water quality parameters such as dissolved oxygen, pH, BOD (1 day, 3 days, 5 days, and 7 days), NH ₄ , NO ₃ ^- phosphate (PO4 ^3- ), and temperature were measured. Morphological and hydrological data were provided and introduced into the model. The model was calibrated and its accuracy was investigated. Results: The results indicated that concentration of PO4 ^3- , BOD₅ , COD, NH ₄ , and NO3 ^- exceeded surface water standards from regulating dam to Pole-Kalleh bridge. The results of the prediction for the next 25 years indicated that due to growth of population and industries along the river, concentration of some pollutants will be increased. Conclusions: The results indicated that although the current DO level is suitable for aquatic environment, this is not adequate for fish reproduction and migration. Prediction of the river water quality parameters for the future conditions showed that discharge of urban and rural wastewater to river should be avoided. In situations where release of effluent into the river is inevitable, nitrification process should be added to wastewater treatment processes.

Aims: The aim of this study was to study the sleep quality of truck and trailer drivers in Yazd and its relation with traffic accidents and associated expenses. Materials and Methods: This cross-sectional descriptive study included nonrandom simple method including 200 truck and trailer drivers. A two-sectional questionnaire was used: the first section included the standard Pittsburgh sleep quality questionnaire, while the second section included demographic characteristics of the subjects. Data were analyzed using descriptive statistical method and T-test analysis through SPSS 17 software. Findings: The mean daily sleep period of the subjects under study was 6.46 ± 1.8 h and the mean of sleep quality score was 7.22 ± 2.72 h. Of the total, 75.5% had a sleep quality score greater than 5 that depicts the low quality of sleep in them. 29.5% had suffered from accidents in the last decade and 28% of those were due to sleepiness. The distribution of the sleep quality score on basis of sleep duration and falling sleep time was meaningful. The distribution of history of cigarettes smoking, narcotics abuse, and use of sedatives on basis of sleep quality score was also significant (P < 0.05). Conclusion: The results showed that 75.5% of the truck and trailer drivers had sleep quality disorders and accidents resulting in injuries. Sleep quality in drivers who had precedence of accidents was lower than the drivers without any accidents so sleepiness can be one of the main causes of accidents among the professional drivers in Iran.

Aims: In this study the concentration of SO ₂ in Khark Island was evaluated via passive sampling. Materials and Methods: The climate of the region and SO ₂ level were investigated during one year. For SO ₂ sampling, sulphatation pages was used and SO ₂ was determined by PbO ₂ method monthly. The climate data was obtained from Khark airport meteorology station. Results: For SO ₂ sampling, the sulphatation pages were installed at six locations in the region for a month. The results indicate the level of this gas is more than air standard. So that, SO ₂ concentration in residential Khark area was more than 8.5 ΅g/cm ² day. Conclusions: High gas concentrations and climate conditions can cause accelerated corrosion of facilities and can have adverse effects on human and natural resources of the island.

Aims: The aims of this study were to determine the efficiency of Kermanshah wastewater treatment plant (conventional activated sludge) and Gilan-e-Gharb wastewater treatment plant (stabilization ponds) in removal of organic matters (BOD ₅ and COD), suspended solids, total coliform, protozoan cyst, and parasitic eggs in order to reuse their effluent for agriculture. Materials and Methods: In this study, the samples were taken every five days from both inlet and outlet of wastewater treatment plants (WWTPs) for five months. Identification and counting of the protozoa cysts and parasitic eggs was carried out using McMaster slide according to Bailenger method. Other parameters were determined according to standard methods. Appropriate statistical techniques (T-test, Kolmogorov Smirnov test, and Mann-Whitney U test, Using SPSS ver. 16) were applied to interpret data. Results: The efficiencies of Kermanshah wastewater treatment plant in removing BOD ₅ , COD, TSS, total coliform, parasitic eggs, and protozoan cyst were 82 ± 4%, 83 ± 2%, 78 ± 5%, 66.2 ± 4.2%, 97-99%, and 99-100%, respectively. The respective efficiencies for Gilan-e-Gharb stabilization ponds were determined as % 84 ± 3, %82 ± 8, %84 ± 5.3, %75 ± 6, %100, and %100. Conclusions: According to the results, the removal efficiencies of all parameters except COD in stabilization ponds are higher than those in the activated sludge. Effluent quality in both plants met agricultural effluent reuse standards in view of all studied parameters except total coliform.

Aims: The purpose of this study was to survey the antibiotics effects of oxytetracycline, tylosin, and amoxicillin on anerobic wastewater treatment process. Materials and Methods: To evaluate the inhibitory antibiotics amoxicillin, tetracycline, and tylosin on biomass activity, specific methanogenic activity (SMA) using anerobic biomass batch; into 120 ml vials: 30 ml biomass and 70 ml substrate including volatile fatty acids, mainly acetic acid and various concentrations of antibiotics were added. Methane gas production replacement through solution of KOH (2 N) as an absorber of CO ₂ and bromine thymol blue as indicator was measured. Each batch was tested for 10 days. Results: Based on the findings, inhibitory concentration of oxytetracycline, amoxicillin, and tylosin were 8000, 9000, and 9000 mg/L, respectively. Conclusions: This study showed that with increasing concentrations of antibiotics, the produced biogas volume from biomass per unit weight is decreased. COD removal was 42-82 % due to long retention time and adsorption to flocks.

Aims: This study deals with molecular identification, susceptibility, and metal biosorption of a Geobacillus genospecies isolated from Deeymand hot spring at the south east region of Kerman, Iran. Materials and Methods: Two samples were collected from water and sediment of the hot spring. Genomic DNA was extracted by sucrose lysis technique and polymerase chain reaction (PCR) was performed using the universal primers corresponding to Escherichia coli 16S rRNA gene. Both strands of the PCR product were sequenced by dideoxy chain termination method. The susceptibility of the isolate to Cu ²⁺ and Ni ²⁺ was determined by broth dilution method. Biosorption of dried biomass for the metal solutions was measured at different time intervals (5-300 min). Effect of temperature on biosorption of Cu ²⁺ and Ni ²⁺ was also determined. Results: Temperature of hot spring was 73°C and pH was 8. As result of sequencing of 16S rRNA gene, it was found that the organism had 99.8% similarity with member of genus Geobacillus. Phylogenetic tree and neighbor-joining phylogeny revealed that the isolate had 99.22% sequence similarity with Geobacillus uzenensis and 99.15% with Geobacillus jurassicus. The isolate exhibited minimum inhibitory concentration (MIC) of 4 mM to Cu ²⁺ and 5 mM to Ni ²⁺ . Minimum biosorption of Ni ²⁺ occurred at 5 min (0.07%/0.1 g biomass) and maximum biosorption occurred at 120 min (29.6%/0.1 g biomass), while minimum biosorption of Cu ²⁺ ion occurred within 5 min (16.6%/0.1 g biomass) and maximum occurred at 210 min (77.8%/0.1 g biomass) (P < 0.05). Biosorption of Ni ²⁺ was the highest at 27°C (89.8%) and Cu ²⁺ biosorption occurred at 65°C (77.8%). Geobacillus genospecies IRKM1 did not carry any plasmid. Conclusions: The above results showed that the isolate was a member of Geobacillus spp. and the thermophilic bacteria was moderately resistant to Cu and Ni metals even though there was not any previous contamination of that biological niche. The organism exhibited highest biosorption of Cu ²⁺ at 65°C and Ni ²⁺ at 27°C. No plasmid was detected in the Geobacillus isolate.

Aims: The efficiency of an anaerobic sequencing batch reactor (ASBR) in ethylene dichloride ( EDC) and chemical oxygen demand (COD) removal at different operational conditions was evaluated. Materials and Methods: Biological EDC and COD removal was studied in a laboratory scale ASBR. The ASBR was seeded at the start-up with granular anaerobic sludge of sugarcane industry and operated at different organic loading rates (OLR), EDC loading rates, and influent concentration of COD and EDC. Results: During start-up period, COD removal efficiencies of above 80% were selected for reactor adaptation to achieve steady state during 48 days of operation. Maximum COD removal efficiency was 95% with an influent COD concentration of 1700 mg/L at 0.5 gCOD/L.d, and the efficiency rapidly dropped with increasing influent COD concentrations and OLR. When the EDC loading rate was adjusted between 0.6 to 4.7 gCOD/L.d, the EDC removal efficiencies were 95% and 46%, respectively, with influent EDC concentrations of 2000 and 16000 mg/L at the end of EDC loading stage. The kinetic study showed that the EDC and COD removal by ASBR followed the second order kinetic. Conclusions: Based on the results of this study, the ASBR process is successfully applicable for biodegradation of the COD and EDC (>90%) in wastewater treatment. The kinetic study showed that, at same time, ASBR capable to removing COD rather than EDC.

Aims: The aim of this study was to investigate the relationship between macroergonomics score and job satisfaction among industrial employees. Materials and Methods: This cross-sectional study was done among 83 employees from a factory affiliated with Iran Khodro Company. Two questionnaires including Minnesota Job Satisfaction and Macroergonomics Condition have been used. Finally, the collected data was evaluated and analyzed through SPSS 10 software program. Results: The mean age of the subjects in this study was 30.8 and the work experience of 56.6% of them was between 4 and 7 years. The average macroergonomics score in the whole group in this study was 59.8. The maximum score given to this condition was 85, and the minimum score was 30. Also, the mean of job satisfaction score among the subjects was 60.5. The highest job satisfaction score was related to supervisors, which was about 69.2. There was a significant relationship between the general area of macroergonomics and job satisfaction. (r = 0.638, P-value <0.001). Conclusions: This study showed the higher macroergonomic scores, the better the work conditions, and, therefore, the employee's job satisfactions improve.

Aims: In this study, humic acid (HA) removal by iron oxide magnetic nanoparticles (IOMNPs) was surveyed in aqueous solutions. Materials and Methods: Batch adsorption technique was used to determine kinetic and isotherm parameters. The effects of pH value, agitation rate, adsorbent dose, contact times and the adsorbate concentrations on the adsorption efficiency were studied as critical parameters. The IOMNPs was characterized by X-ray diffraction. Results: HA adsorption on the IOMNPs was fitted with Freundlich isotherm model and followed the pseudo-second-order kinetics. Results revealed that at HA concentration of 10 mg/L, pH 4.5, adsorbent dose of 2.7 g/L, agitation rate of 250 rpm and contact time of 90 min at presence of 0.1 M NaCl as an ionic strength agent, the HA removal reached to about 98%. Also, the turbidity of treated samples was increased with increasing of HA loading. Conclusions: With increasing HA concentrations, adsorption capacity of IOMNPs was increased and HA removal efficiency was decreased. By adding ionic strength, HA removal was improved and turbidity of treated samples was reduced.

Aims: This study was aimed to design comprehensive risk management based on hazard analysis and critical control points (HACCP) in the Isfahan drinking water system. Materials and Methods: Data obtained from field inspections and through related organizations of Isfahan, Iran. The most important risks and risky events of water quality in all sources of raw water in the study area including the Zayanderoud river, the water treatment plant, and the distribution system were identified and analyzed. Practical measures for the protection, control, and limitation of the risks in different phases, from water supply to consumption point, were presented in the form of seven principles of the HACCP system. Results: It was found that there was a potential of hazards during the treatment process of water because of seasonal changes and discharge of various pollutants. Water contamination could occur in eight identified critical control points (CCP). River water could be contaminated by rural communities on the banks of the river, by natural and sudden accidents, by subversive accidents, by incomplete operation, by lack of proportionate of the current treatment process, and by the high extent of antiquity of the Isfahan water distribution system. Conclusions: In order to provide safe drinking water, it is necessary to implement a modern risk management system such as the HACCP approach. The increasing trend of the Zayandehroud river pollution needs urgent attention. Therefore, the role of the government in developing and mandating the HACCP system in water industries is essential.

Aims: The aim of the present study is to investigate the efficiency of ultraviolet/ nickel oxide (UV/NiO) system as one form of advanced oxidation processes (AOP) for decolorization of red poly azo. Materials and Methods: This study was conducted as a laboratory scale in a batch mode. Ultraviolet radiation was provided by a low pressure (11 W) UV lamp. Effects of various factors including pH, different irradiation durations, different concentration of nickel oxide, and initial dye concentration were evaluated. Results: The results of the UV/NiO system's assessment showed that UV light alone cannot remove DR 80 dye. Nickel oxide is an effective catalyst in the decolorization of dye with the nanophotocatalytic process. The decolorization efficiency increases with decreasing pH value and the optimum pH value is 4. Fainally, the highest removal efficiency achieved by UV/NiO process for DR 80 dye with concentrations of 25 mg/l and 50 mg/l was 94.3% and 82.2%, respectively. UV/NiO-based decolorization process follows pseudo-second-order reaction kinetics. Conclusions: From the findings of the present study, it can be concluded that UV/NiO process is an effective technique for decolorization of poly azo dye, DR 80, in aqueous solutions.

Aims: This study was conducted to evaluate the feasibility of applying pumice as a catalyst in the ozonation process for removal of humic acids from aqueous solutions. Materials and Methods: The molecular structure and chemical composition of pumice were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD). The catalytic ozonation experiments were performed in a semi-batch reactor and the mass of ozone produced was measured by means of iodometric titration methods. Concentration changes in humic acid were determined using a spectrophotometer, at an absorption wavelength of 254 nm. To evaluate the performance of catalytic ozonation in humic acid removal, effects of different parameters including pH, contact time, pumice dosage, and t-butyl alcohol (TBA) were examined. Results: The catalytic ozonation results showed that the use of pumice as a catalyst increased the decomposition of humic acid eight times, and the removal efficiency increased as the pH changed from 4 to 12 and catalyst dosage changed from 0.25 to 10 g/l. The catalytic ozonation with considerable efficiency (90%) removed humic acid in less time (10 minutes) than the sole ozonation process (SOP). Moreover; the results indicated that the catalytic ozonation process (COP), compared to conventional SOP, was less affected by the radical scavenger. Conclusions: Due to the low cost, easy access, and remarkable performance of pumice as a catalyst, it can be used in conventional sole ozonation processes for removing organic pollutants.

Aims: This study evaluates the effectiveness of polyaluminium chloride (PACl)as a coagulant for enhanced coagulation (EC) of humic substances (HS) in surface water. Materials and Methods: Dissolved organic carbon (DOC), ultraviolet absorbance (UV ₂₅₄ ), specific ultraviolet absorbance (SUVA), and humic acid (HA) were determined as the HS indices. HS was extracted by Amberlit XAD-7HP from water and HA was analyzed by high performance liquid chromatography (HPLC). The HS index was determined in raw water and after clarification and filtration in all seasons. The efficiency of PACl for removal of HS, both in the jar test and pilot scale were determined. Results: The average extraction efficiency for XAD-7HP was 77%, and the HA concentration was determined in all seasons ranging from 0.15 to 0.29 mg/ L in raw water. The DOC in raw water was in the range of 1.5 to 4mg/L, in all seasons. The average removal efficiency of PACl for EC was 52% for HA in the pilot scale. Also the average removal efficiencies of PACl EC for DOC and UV ₂₅₄ were 43 and 57% on the pilot scale and 38 and 41% in the jar test, respectively. The optimum pH for removal of HS was 7.5 ± 0.2 and the optimum PACl dose was 12 ± 0.5 mg/L. Conclusions: After EC, the aluminum concentration was lower than the maximum concentration level (MCL) of aluminum in drinking water (< 0.05 mg/L). The efficiency of PACl EC was more effective in the high molecular weight fraction of HS and UV ₂₅₄ . In addition, PACl EC was more affected by the increasing coagulant dose than the pH decrease. The removal efficiency of PACl EC at high pH > 8.5 was very poor for the HS index and turbidity.

Aims: In the present investigation, the methyl tertiary-butyl ether (MTBE) removal efficiency from the synthetic solutions by the means of advanced oxidation process of UV/O ₃ was studied. Materials and Methods: To study the efficiency of process, the following variables were studied: ozone concentration, pH, MTBE initial concentration, and radiation duration. As The radiation source, a Mercury vapor UV lamp with moderate pressure (400W) was used which was immersed vertically in the solution containing MTBE, in a glass reactor (Volume: 2 L). Results: The results showed that the efficiency of UV radiation and ozone alone in 50 mg/L concentration and pH: 7 on MTBE removal was 4 and 53%, respectively. The UV/O ₃ compound process removal efficiency in 60 minutes was 63%. The pH played a significant role in the process, as with the increase in pH, the removal rate increased as well. The removal rates for the initial concentrations of 10, 20, 50, and 100 mg/L of MTBE were 98, 81.5, 72.8, and 63.8%, respectively. Conclusion: The results of the present survey indicated that the efficiency of the UV/O ₃ combination process was more than ultraviolet (UV) and Ozone alone. In the UV/O ₃ combination process, the MTBE removal efficiency increased as the O ₃ concentration and pH increased, while the efficiency decreased as the MTBE concentration decreased.

Aims: Inhibition behavior of two types of antibiotics including Ampicillin and Gentamicin on specific methanogenic activity of anaerobic biomass has been investigated. Materials and Methods: A total of 18 Specific Methanogenic Activity (SMA) tests were conducted in 120-ml vials containing 40 v/v% substrate, 37 v/v% biomass and 23 v/v% biogas in batch mode for 20-25 days. Produced methane was measured by gas replacement with 2N KOH solution as CO ₂ absorbent. Three volatile fatty acids (VFAs) including acetic acid, propionic acid, and butyric acid were used as co-substrate. Results: In the tests with 200, 500 and 1000 mg/l of ampicillin at presence of acetic acid, the cumulative SMA were 66, 101, and 154 ml CH ₄ /g VSS.d, those of with propionic acid were 25, 35, and 46 ml CH ₄ /g VSS.d, and with butyric acid the values of 198,140, and 245 ml CH ₄ /g VSS.d were obtained respectively. In the experiments with 100, 500 and 1000 mg/l of gentamicin the cumulative SMA were 141, 204, and 257 ml CH ₄ /g VSS.d for acetic acid as a substrate, 54, 72 and 71 ml CH ₄ /g VSS.d for propionic acid, and 139, 74, and 85.5 ml CH ₄ /g VSS.d for butyric acid, respectively. Conclusion: At the same concentrations, ampicillin showed more inhibitory effect than gentamicin on anaerobic decomposition of biomass. Within the used VFAs, the inhibitory effects of propionic acid was greater than acetic acid and butyric acid.

Aims: The purpose of this study is to investigate the feasibility of the absorption of lead and cadmium from the leachate, by natural zeolite clinoptilolite and improving the zeolite ability by a modified surface. Materials and Methods: To examine the absorption ability of these two metals (lead and cadmium), the variables, such as, type of sorbent, sorbent concentration, and contact time were studied. Zeolite samples were analyzed by X-ray florescence, the spectrum of X-ray diffraction, and Brunauer-Emmett-Teller (BET). Results: The absorption efficiency of the modified zeolites were increased from 4.2 and 5.3 percent to 71.6 and 75.2 percent for lead and cadmium, respectively. With increasing the surfactant concentration from 2 to 20 mmol/L, the absorption efficiency of modified zeolite for lead and cadmium was increased to 71 and 74%, respectively. The best isotherm model for lead adsorption was Freundlich model, with a determination coefficient equal to 0.99, and for cadmium it was Langmuir model with a determination coefficient equal to 0.99. Conclusions: The modified zeolite with surfactant can be used as an appropriate adsorbent for the separation of heavy metals from waste Leachate. Lead and cadmium were absorbed in a single layer on the surface of the modified zeolite with surfactant, comparing different isoterm models, indicated that the capacity of the modified zeolite for lead adsorption was more than cadmium adsorption, but cadmium was absorbed with higher energy.

Aims: In this study, the adsorption process using nickel oxide nanoparticles was studied in a laboratory scale for wastewater treatment containing mono azo Orange II dye. Materials and Methods: The effect of various parameters such as initial dye concentration, pH, contact time and different concentrations of nickel oxide was investigated. The adsorption experiments were done with different concentrations of dye in a solution using a specific amount of nickel oxide nanoparticle with different pH values and a agitator speed of 100 revolutions per minute (rpm) for about 2 hours. Samples were centrifuged and the concentration of each dye was determined by ultraviolet (UV)-Vis spectrophotometer (DR 5000). Results: Based on obtained results, the optimum pH range to dye removal is acidic pH, and under lab conditions, 0.6 g/L of nickel oxide can completely remove the 50 mg/L of dye. Although increasing the dye concentration resulted in decreased process efficiency, up to 100 mg/L of dye concentration, considerable efficiency was obtained. Conclusions: The data showed that the nickel oxide nanoparticles could be used as an efficient adsorbent for decolorization of azo dyes.

Aims: The object is to find a manner of reduction primary noise from a source by an electro acoustic device that cancels unwanted sound by generating an anti sound (anti noise) of equal amplitude and an opposite phase is described as an active noise control system. Materials and Methods: In this method, the primary noise is acquired via a microphone, and the anti noise propagates with the same amplitude and the reverse phase at the primary noise path via a speaker to cancel the original noise. The effectiveness of cancellation of the primary noise depends on the accuracy of the amplitude and phase of the generated anti noise. Results: The results present a noise reduction of 16 dB until 20 dB overall. A change in the system setup and noise power can reach a noise reduction up to 25 dB. Perhaps, this is due to the background noise and primary noise differences that create a powerful anti noise for canceling the original noise. Conclusions: With regard to the wide range of frequencies of different noise sources, having optimized circumstances in the duct, microphone location on the duct body or even the distance of the speakers may be important in signal processing, noise sampling and anti noise production.

Aims: Antibacterial effects of hydrogen peroxide and silver composition on selected pathogenic enterobacteriaceae was investigated in this study. Materials and Methods: The efficacy of 30 ppb silver in 0.3% hydrogen peroxide solution for inactivation of selected Enterobacteriaceae, including Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae was assessed for 72 hours in a designated nutrient broth medium and steel surface. The bactericidal growth ability was determined for each bacterium genus by the conventional colony count method and turbidimetry via an optical density (OD) assay at 450 nm in a time interval of 24 hours. Results: Suspensions of K.pneumoniae, and P.mirabilis showed a significant OD reduction at three 24-hour intervals (CI = 0.95; P < 0.05, for both), along with blocked growth in a designated broth medium during 24 to 48 hours of exposure. The disinfectant was also significantly efficient for inactivating of the mentioned bacteria on steel surfaces after a 15-minute time exposure (CI = 0.95; P < 0.05). For E.coli, the OD decreased slightly during the initial exposure time, but increased after 24 hours. Viable E.coli cells were proved by colonies grown on the plate. A qualitative surface decontamination test showed that three pathogenic bacteria were inactivated significantly after disinfectant exposure (CI = 0.95, P < 0.05). Conclusions: In conclusion, a combination of hydrogen peroxide and silver ions was proposed as a strong disinfecting agent both in suspensions and on the surfaces against these three important human pathogens.

Aims: This study aims to evaluate the performance of the anaerobic sequencing batch biofilm reactor (ASBBR) for biodegradation of Benzene-Toluene-Xylene (BTX) that is present in petrochemical synthetic wastewater. Materials and Methods: A laboratory-scale ASBBR was used to treat a synthetic substrate mixture representing petrochemical wastewater that contained BTX. The operation schedule was: Fill time: 10 minutes, reaction time: 22.8 hours, settling time: 60 minutes, and decant time: 10 minutes, at 35΀C. The BTX samples were analyzed by gas chromatography-flame ionization detector (GC-FID) equipped with head space. Results: After reaching to stable operation, the reactor was exposed to influent BTX concentrations of 5, 20, and 50 mg/l, with overall organic loading rate of 3 g COD/l.d resulting in 61, 79, and 50% removal efficiencies for the BTX, respectively. At this time, the removal efficiencies for COD were 75, 90, and 70%. Conclusions: The optimum BTX removal of 79% was achieved in 3 g COD/l.d and HRT of 3.8 days, at influent BTX concentration of 20 mg/l. Thus, it could be concluded that ASBBR was a feasible, efficient, and consistent technology for treatment of petrochemical wastewaters containing BTX. The ASBBR might be an alternative to intermittent systems as well as batch systems due to its superior operational flexibility.

Aims: Evaluation of heat stress in workers exposed to hot/dry conditions of melting and casting industry is imperative for management of heat stress. This study aims to compare results of heat strain evaluation by monitoring environmental factors and physiological responses. Materials and Methods: This is a cross-sectional study that was conducted on 51 workers of a large melting and casting company in 2010. Wet Bulb Globe Temperature (WBGT) index, heart rate and ear canal temperature were measured by WBGT meter, heart rate monitor and personal heat stress monitor, respectively. Physical activity intensity was assessed based on the ratings of perceived exertion (RPE). Data were analyzed using descriptive statistics and Pearson correlation test. Results: WBGT index in 64.7% of workstations exceeded 30°C and in 41.2% was over 32°C. The value of WBGT index in 69% of work stations exceeded the threshold limit of the ACGIH standard. The physiological strain index (PSI) in 31% of worker was higher than 5, although its mean measured at 3.8 (1.8). Increase in the ear canal temperature in 64.7% of cases (33 persons) was over 1°C. Correlation between WBGT index with ear canal temperature and PSI index, adjusted body mass index and age, was 0.67 and 0.69 (P < 0.0001). Conclusion: In hot/dry conditions of melting and casting processes, despite moderate correlation between WBGT index with ear canal temperature and PSI index, work-rest cycles of WBGT index is not applicable for many of the workstations. Therefore, heat stress evaluation based on physiological variables probably has higher validity and is more appropriate.

Aims: The aim of this study is to find manners of noise abatement to reach to its allowable values by which the noise caused by compressors can be reduced, and if use of enclosure is an effective alternative. Materials and Methods: In the study, analysis of noise caused by the compressor and how distribution of sound frequencies with and without the use of enclosure was done, and then compared with standard values to help choose the best absorber material. This method is in accordance with the in situ assessment techniques for noise generated by different sources. A second order analyzer was use to study the recorded sound pressure level (SPL) values, and to demonstrate which frequencies can be more important in designing the enclosure. A sheet metal was used for enclosing the compressor, and this was lined with an absorber material to achieve a better sound reduction. SPL levels, before and after the enclosure of the compressor with the sheet material, were measured and compared. Results: There was a reduction in the level of noise produced for all frequencies due to use of the enclosure, a difference of 10 to 50 dB of reduction was recorded for all the frequencies. For higher frequencies in the range of 500 Hz to 4000 H, the SPL showed a similar reduction. A reduction of 50 dB in the produced noise below the standard was seen for the frequency of 63.5 Hz in octave band frequencies. There was also a permissible limit for higher frequencies of noise produced by the compressor, but with a gap of 10 dB of its standard limit at the frequency of 500 Hz. Conclusions: An overall noise reduction by 25 dB with the use of mineral wool as an extra liner on the inside of the enclosure, suggests that the effectiveness of the enclosure can be increased by using such absorber materials.

Aim: In this paper, the feasibility of flat-sheet membrane bioreactor (FS-MBR) for municipal wastewater treatment was studied. Materials and Methods: In this study, treatment of municipal wastewater in a submerged FS-MBR was investigated under different aeration time and flux. A bioreactor consist of microfiltration membrane (MF) and actual municipal wastewater as influent stream. The FS-MBR was operated during 161 days. Results: The result showed that average removal efficiencies of chemical oxygen demand (COD), biological oxygen demand (BOD ₅ ), total suspended solids (TSS) and volatile suspended solids (VSS) were obtained >90% and with variation of influent COD, BOD ₅ , TSS and VSS, the removal efficiency no significantly change. The mixed liquor-suspended solids (MLSS) and mixed liquor volatile-suspended solids (MLVSS) concentration during experiment increases from low concentration to about 7.9 and 6.5 g/L, respectively. The average of PO4 ³⁺ -P, total kjeldahl nitrogen (TKN), ammonia and fecal coliform (FC) removal efficiency during the operation period was 62, 98, 70% and 8 log, respectively. Conclusion: It is concluded that FS-MBR can be used in the large scale municipal wastewater treatment plants to improve effluent quality due to high removal of COD, BOD ₅ , TSS and VSS to meet effluent discharge standards.

Aims: The aim of this study is to evaluate the combined application of wet bulb globe temperature (WBGT) and physiological strain Iindices based on heart rate (PSI _HR ) for the estimation of heat strain, in hot climatic conditions. Materials and Methods: This cross - sectional study was conducted on 122 men including 71 and 51 workers from the Assaluyeh National Petrochemical Company and Isfahan Steel Company in the center and south of Iran, respectively. The WBGT index, heart rate, and auditory canal temperature were measured at rest and when working. The data were analyzed using descriptive statistics and logistic regression. Results: The results of the logistic regression indicated that the WBGT index was a poor predictor of heat strain and its sensitivity and specificity were 53 and 65%, respectively. However, the combined application of the WBGT and PSI _HR indices was a better predictor of heat strain, and the sensitivity and specificity of this combination were 75 and 69%, respectively. Conclusion: According to the results of this study, the combined application of the WBGT and PSI _HR indices can be used as a valid estimator of heat strain in hot climatic conditions in the center and south of Iran.

Aims: This study is aimed at assessing the effectiveness of Cannabis sativa in the absorption of cesium and strontium elements from the soil. Materials and Methods: This study was conducted in 2011, in Tehran, Iran. We employed the phytoremediation technology to refine the contamination of soil with radioactive material such as cesium and strontium. Cannabis sativa was selected because of its capability for potential radioactive absorption. It was planted in various soils with different concentrations of cesium and strontium (20 ppm, 40 ppm, 60 ppm, and 80 ppm), and after sufficient growth for about six months, it was separated into root, stem, and leaves for measuring the absorption of these elements in the main parts of the plant. The samples were measured by using the Inductively Coupled Plasma (ICP) method. Results: Strontium absorption and the main parts of the plant showed a significant relationship. The percentage of strontium absorption was 45% in the root, 40% in the stem, and the minimum absorption was found in the leaves (15%), but the corresponding figure was not significant for the cesium element. A strontium concentration of 60 ppm was possibly the maximum absorption concentration by Cannabis. Conclusion: Our findings suggest that strontium can be absorbed by Cannabis sativa, with the highest absorption by the roots, stems, and leaves. However, cesium does not reach the plant because of its single capacity and inactive complex formation.

Aims: The purpose of this study was to evaluate the performance of the sequential application of ozonation and activated carbon processes in the elimination of water-soluble crude oil and thereby reducing total organic carbon (TOC) and toxicity for the rainbow trout larvae. Materials and Methods: A series of water-soluble fractions of crude oil, 5-100 ml/l, were prepared. Groups of ten rainbow trout fish larvae were exposed to the solution for 24, 48, and 96 hours. Toxicity (LC ₅₀ : Median lethal concentration) and TOC tests were performed for the solutions before and after their treatment by sequential ozonation and activated carbon adsorption. Results: The LC ₅₀ (96 hours) and TOC of the sample before the treatment process were 60 mg/l and 55 mg/l, respectively. After adsorption by 10 mg/l activated carbon, followed by ozonation with a concentration of 1 mg/l, the LC ₅₀ increased to 145 mg/l and TOC reduced to 36 mg/l. Those values, after treatment with 30 mg/l activated carbon, followed by 7 mg/l ozone, reached 196 mg/l and 28 mg/l, respectively. In the experiment, ozonation by 1 mg/l ozone was applied, and then adsorption was carried out by 10 mg/l activated carbon, and the LC ₅₀ was 149 and TOC was 35 mg/l. In the experiments with 7 mg/l ozone followed by 30 mg/l activated carbon, LC ₅₀ reached 204 mg/l and TOC reduced to 28.5 mg/l. Conclusions: Primarily ozonation of crude oil polluted waters followed by adsorption by activated carbon can increase the removal efficiency of the process, which results in significant TOC and toxicity reduction.

Aims: The purpose of this study was to use a combinational process of catalytic oxidation of hydrogen peroxide (CWPO) and activated carbon for improving the removal efficiency of organic matter. Materials and Methods: The effect of the operational parameters such as residence time (30 - 90 minutes), reaction temperature (100-300°C) in the pressure 10 bar, and catalytic iron concentration were investigated. The effect of the catalytic method, catalytic wet peroxide oxidation (CWPO), along with the absorption process, on granular activated carbon (GAC), powdered activated carbon (PAC), PAC/Cl ₂ , and GAC/Fe were considered; oxygen is used to supply pressure and H ₂ O ₂ is applied as the main oxidant in various concentrations. Results: The removal efficiency of the chemical oxygen demand (COD) was over 35%, obtained in one hour of retention time, with the wet air oxidation (WAO) process, and the removal efficiencies of GAC, PAC, and PAC/Cl ₂ , at a temperature of 300°C, and activated carbon concentration of 2 g/l, were 43.4, 38.9, and 33.6%, respectively. Conclusion: These results indicate that the reaction temperature, residence time, and H₂O₂ dose are the most important factors affecting the degradation of organic matter. The GAC/Fe catalyst process had a higher efficiency than other absorbents for organic matter oxidation.

Aims: The goal of this study was the ultimate analysis and chemical composition of SW for energy recovery in Urmia city. Materials and Methods: A cross-sectional, descriptive study was done on municipal SW in Urmia city, northwest of Iran. The samples were collected during the four seasons of a year. Experiments were analyzed according to the American Society for testing and Materials (ASTM) Method D 5231-92. The chemical composition of the SW was calculated, to determine the quantity of produced biogas and heat value. Results: The findings showed that food waste percent had been 68.9%, carbon/nitrogen (C/N) 18.33, containing 10.4% ash and 54% moisture. The calculated chemical composition of organic SW was (C_27.7 H_43.1O_15.3 N₁S_0,065) with a heat value of the 2.2 × 10⁴ Kj/Kg. The produced methane and heat value of the biodegradable organic SW, chemical formula C _23.63 H _37.52 O _14.65 N ₁ S _0.069 , were 212 liters (151 g) and 9992 Kj per 1 Kg of SW. Conclusions: The recovery of SW energy through incineration was a better choice, due to the high heat value. However, it would produce more than 300 tons/day of greenhouse and poison gases, but land filling produced 200 tons/day of different gases. Thus, on the basis of the calculated SW composition in this research, it seemed that energy recovery through methane collection was a better option for this study area.

Aims: This study has been conducted to focus on the localization of the design parameters used for the design of wastewater treatment plants in a region of Iran. Materials and Methods: Three wastewater treatment plants were selected (as models) in a cold weather region of Iran. The main characteristics of the wastewater, such as, flow rate and its fluctuations, total solids, and the organic and nutrient contents, which play an important role in the design and operation of the wastewater treatment facilities, were measured for the selected plants during a year. Results: The averages of the design parameters for the investigated plants, including, biochemical oxygen demand (BOD ₅ ), chemical oxygen demand (COD), total suspended solids (TSS), volatile suspended solids (VSS), total Kjeldahl nitrogen (TKN), and total phosphorous (TP) were, 41, 60, 65, 47, 8.3, and 0.93 g/capita, respectively. Wastewater production was 177 lit/cap-day with a maximum and minimum coefficient of 1.76 and 0.29, respectively. Conclusions: Using design parameters based on the local characteristics and the real-world conditions of the wastewater, can result in more+operational efficiency in the wastewater plants. It is suggested that the results of this study can be applied to the design of wastewater facilities throughout Iran, with the same local conditions.

Aims: The objective of this study is to investigate the levels of lead (Pb) and cadmium (Cd) in the vegetables from the farms of Gorgan, Iran, and compare them with the permissible levels proposed by the Food and Agriculture Organization (FAO) and World Health Organization (WHO) standard. Materials and Methods: In this descriptive study, 40 samples of irrigating water and vegetables were collected, between the periods of August and December 2008. The Polarography apparatus was used to determine the amount of cadmium and lead after sample preparation. The level of significance was set at 5% for all the tests Result: The cadmium concentrations in spinach, garden cress, and radish were 0, 0.085, and 1.56 μg.kg ^-1 , respectively. The lead concentrations in spinach, garden cress, and Radish were 51.21, 40.13, and 87.27 μg.kg ^-1 , respectively. The cadmium concentration in irrigating water was not detectable with the Polarography apparatus. However, the lead concentration in water was 26.75 μg.kg ^-1. There was no significant variation between the cadmium levels in spinach and garden cress (P<0.05), while there was a significant difference between the amount of cadmium in radish and spinach and garden cress (P<0.05). Conclusion: All the vegetables and water contained Pb, although Cd was lower than the permissible levels proposed by FAO/WHO and might not cause health hazards to consumers.

Aims: This research was conducted to study the effects of the electrical conductivity (EC) of irrigation water and compost on the Cadmium (Cd) and Zinc (Zn) uptake by sunflower, Helianthus annuus. The transfer of Cd and Zn from soils close to the Zn mine, to the sunflower tissues, and the interactions between the two concerned metals, were also investigated. Materials and Methods: For this purpose, 10% weight/weight from municipal composts was applied to raw soils that were randomly collected from the mine region. Series analyses were also implemented by irrigation water, with EC values in the range of 0, 2, 4, and 6 dS/m. Results: The maximum uptake rate of Cd, with EC levels of 6 dS/m, in plant samples was 4.82 μg/g for the roots, 6.14 μg/g for the stems, and 5.4 μg/g for the leaves; and the maximum uptake of Zn, in plants irrigated with tap water, was 241 μg/g by the roots, 624 μg/g by the stems, and 229 μg/g by the leaves, respectively. Conclusions: Results showed that high EC levels of irrigation water increased Cd accumulation and decreased Zn accumulation in the shoots. The presence of high EC levels in irrigation water negatively affected biomass production by plants. Chlorine ion (Cl-) had a positive influence on Cd accumulation in the harvestable parts of the plant.

Aims: The objective of this study was to determine the malachite green (MG) concentration in trout tissue and the effluent water of fish farms, at one of the largest trout fishery industries in Iran. Materiels and Methods: Twelve samples of water and fish tissue were collected from fish farms placed at the upstream ends of two large rivers in the study area. The samples, after extraction, were analyzed with liquid chromatography-mass spectrometry (LC-MS). The effluent water samples were also analyzed by the spectrophotometric method after cloud point extraction using the anionic surfactant Triton X-100. Results: The concentration of malachite green in the fish samples ranged from 265.2 to 1663 μg/kg, which is more than the recommended maximum allowable concentration by the Codex standards. MG in the water samples ranged from 5.65 ng/L to 384 μg/L. The equivalent concentrations of MG in the two large rivers in the study area were 1.78 and 0.62 ng/L, and the total MG load for these two rivers, with a fish production rate of 10,000 tons per year, was around 644 kg/d. Conclusion: We concluded that the concentration of MG used as an antimicrobial chemical in trout fish tissues and water samples in this study were out of compliance with the existing standards. Therefore, the fish products of these farms could cause serious public health hazards, and the discharge of the effluent from these farms, without treatment, posed potential environmental problems.

Aims: This study has been conducted to assess air pollution, with respect to particulate matter less than 10 μm in diameter (PM ₁₀ ), sulfur dioxide (SO ₂ ), carbon monoxide (CO), nitrogen dioxide (NO ₂ ), hydrogen sulfide (H ₂ S), and the Air Quality Index (AQI), in a location at close proximity to the Bandar Abbas-Iran oil refinery. Materials and Methods: In this study, a location with close proximity to Bandar Abbas oil refinery was selected as the sampling station. The Air Sampling period was from June to September 2010. In order to assess PM ₁₀ concentrations, the samples were collected using a high volume sampler with fiberglass filters. To measure the concentrations of other air pollutants, including, SO ₂ , CO, H ₂ S, and NO ₂ , real-time instruments were used. With regard to air pollutant concentrations, the AQI values were calculated and for the wind rose, the effect of the oil refinery on Bandar Abbas was evaluated. Results: According to the results from the present study, PM ₁₀ , SO ₂ , nd NO ₂ concentrations were higher than the recommended values of the national ambient air standards. The maximum PM ₁₀ and SO ₂ concentrations and their resultant AQI values were observed in August and September, respectively. Other air pollutants had their highest concentrations in July and September, but in no case did they exceed the standard values. Conclusion: The three most significant outdoor problems with the air quality around Bandar Abbas oil refinery were the NO ₂ , SO ₂ , and PM ₁₀ levels.

Aims: In this study, the heavy metal contamination of consumable table salt, both unrefined and refined, was investigated. The provisional tolerable weekly intake (PTWI) of heavy metals just by edible salt, of the Isfahan population, was also estimated. Materials and Methods: Twenty samples of salt, including 15 refined and five unrefined were analyzed. Precision of the analysis was assured through repeated analysis of the five samples, which had a great demand in the city. The heavy metal content in the samples was analyzed with Flame Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma (ICP). The PTWI of the metals was calculated by a formula and by using the Iranian average body weight. Results: The mean and standard deviations of cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), copper (Cu), and zinc (Zn), in refined table salts were 0.15 ± 0.02, 0.57 ± 0.1, 0.69 ± 0.09, 0.061 ± 0.008, 0.87 ± 0.11, and 6.34 ± 1.08 μg/g, and those in the unrefined ones were 0.16 ± 0.02, 0.61 ± 0.13, 0.63 ± 0.07, 0.058 ± 0.004, 0.86 ± 0.06, and 7.53 ± 2.93 μg/g, respectively. A PTWI via salt consumption was in the range of 0.8 - 3.1 percent. Conclusions: There was a significant difference between the heavy metal concentrations and their guideline values. Estimation of the health risk due to heavy metals was not possible as PTWI showed total intake of a metal by total food consumption during a week. Therefore, it was important to assess the public health risks arising from the presence of these toxic contaminants in the foods consumed by the population of Iran.

Aims: The objective of this study was to investigate an Upflow Anaerobic Sludge Blanket (UASB) reactor efficiency in treating municipal landfill leachate, under tropical temperature. Materials and Methods: A 30-liter pilot-scale UASB reactor was used to treat the municipal solid waste leachate, under tropical temperature, for 230 days. The reactor was inoculated with 10 liters of anaerobic sludge from an anaerobic digester, in an agro industry's wastewater treatment plant. The Volatile Suspended Solids (VSS) of sludge were 65 g/L, with volatile suspended solids to suspended solids (VSS/SS) ratio of 0.74. The reactor was operated in mesophilic (34 - 39°C) temperature. Results: After reaching a stable operation, the reactor was exposed to raw leachate, with mean chemical oxygen demand (COD) concentrations of 35 g/L. The leachate was diluted to 9 - 10 g/L at Organic Loading Rates (OLRs) of 2, 6, 12, 15 g COD/L.d and decreased again to 12 g COD/L.d, resulting in 45, 76, 84, 68, and 79% removal efficiency and increased again to 87% removal efficiency for COD, at Hydraulic Retention Times (HRTs) of 6, 1.6, 0.83, and 0.67 days, respectively, in the UASB. In the reactor used in this study, the heavy metals were removed by adsorption on biomass, and the maximum removal rate was 68% for Zinc (Zn). Conclusions: It was concluded that the optimum OLR for diluted leachate up to 10 g COD/l, was 12 g COD/L.d at an HRT of 0.67 day (16 hours).

Aims: There is limited data on the occurrence of E. Coli O157: H7 in water. Therefore, this study aims to detect E. Coli O157: H7 in the Water Treatment Plant (WTP). Materials and Methods: This cross-sectional study was conducted in Isfahan WTP, central of Iran. Immunological methods were implemented with anti-serum kits and the molecular method of reverse transcription-polymerase chain reaction (RT-PCR) was used to detect E. Coli O157: H7 in eight locations of the WTP; the sludge of the sedimentation basin and filter backwash water were also monitored. The survival of E. Coli O157: H7 in the sludge samples of the sedimentation basin was indicated by the formation of agglutination particles using the immunological method, and through indicator probes using the RT-PCR method. Results: E. Coli O157: H7 was not detected in the water samples from the WTP units. The removal percent of total coliforms (TC), fecal coliforms (FC), and Heterotrophic Plate Count (HPC), respectively, were as follows: 59.5, 49, and 54.8% in the sedimentation basin; 66, 45.8, and 57% in the ozonation system; 98.8, 98, and 78.8% in the filtration system; and 96, 100, 91% in the disinfection system. Conclusions: This study revealed the existence of the pathogenic coliform of E. Coli O157: H7 in the sludge of the sedimentation basin. The absence of E. Coli O157: H7 in the finished water indicated that the WTP units were able to eliminate these pathogenic bacteria before reaching the final units of the plant, including the filtration and disinfection systems.

Aims: In the present study, Vensim was used to simulate waste management system of Tehran, the capital of Iran, with the system dynamic approach. Materials and Methods: The environmental system dynamic modeling is one of the comprehensive simulation tools capable of simulating and analyzing complex systems. In this approach, the model is developed based on the existing realities and userâ€'comments. User participation to develop the model could increase the reliability of the results. Results: The simulation results revealed good conformity with the statistical data. Waste production prediction in the model with real data was more than 95%. Moreover, the effect of applying an encouraging policy for people to separate their waste was considered. The result indicated that applying a new policy, and the economic benefit through this policy would prevent getting a loan from the government after 20 years. Conclusions: It could be concluded that public participation in waste separation was an effective policy to help in the financial independence of the municipality in terms of urban waste management. Moreover, conformity between the simulation results and real data revealed an appropriate capability of the simulated model to predict Tehran waste generation.

Aims: The ability of raw and recycled multi- and single-walled carbon nanotubes (MWCNT and SWCNT) for xylene adsorption from aqueous solutions was evaluated. Materials and Methods: Batch adsorption experiments were conducted in 110 ml glass bottles. Gas chromatography-mass spectrometry was used for xylene measurement and the carbon nanotube characteristics were evaluated with the help of a transmission electron microscope. Results: With a carbon nanotube dose of 1 g/l, xylene concentration of 10 mg/l, pH 7, and a contact time of 10 minutes, the equilibrium adsorption capacity (q _e (mg/g)) of SWCNT was 9.2 mg/g, which was higher than that for MWCNT (8.9 mg/g). The SWCNT revealed a better performance for xylene sorption than the MWCNT. Results of a desorption study showed that xylene adsorbed onto the SWCNT and MWCNT can be easily desorbed at 105 ± 2°C. Conclusions: It is concluded that recycled carbon nanotubes on heating for the first time, show a better performance for xylene adsorption than when they are raw. The SWCNT are efficient as xylene adsorbents in an environmental pollution cleanup.

Aim: In this study the performance of a natural nanozeolite, modified with a cationic surfactant, on the adsorption of humic acid from water was investigated in a batch system. Materials and Methods: Clinoptilolite as a natural nanozeolite was modified with different doses of a cationic surfactant solution, hexadecyltrimethylammonium bromide (HDTMA-Br), at dosages from 0.5 to 10 g/l. The modified adsorbents were individually added to synthetic water samples containing a known amount of humic acid and put on the shaker for two hours, at room temperature. Humic acid (HA) concentrations, turbidity, and pH were measured before and after the adsorption process. Results: According to the results obtained, and based on the statistical analysis (Pearson correlation statistical test), there was a clear correlation between the cationic surfactant dosage and HA removal (P_value <0.001, r=0.87). By increasing the HDTMA-Br dosage, the ratios of turbidity/turbidity _initial and UV ₂₅₄ /UV _254-initial adsorbance by HA (after/before adsorption process) were decreased. In HDTMA-Br dosages of 7 and 10 g/l, the maximum removal efficiency for HA was 96 and 86%, respectively, with a slight variation in the pH value and turbidity unit. Conclusions: This study showed that modification of nanozeolite by cationic surfactants, to reduce its negative surface charge, could markedly improve its efficiency in the adsorption of disinfection by-product precursors from an aqueous solution. The HDTMA-Br/Clinoptilolite nanozeolite (CNZ) ratio of 0.07, pH have to coincide in iso-electric point, can be an optimum ratio for the modification.

Aims: The aim of this study is the recovery of municipal refuse and using it as a biosorbent for Nickel (II) and Chromium (VI) (Ni ^{2+ an} d Cr ⁶⁺ )removal from aqueous solutions. Materials and Methods: Activated sludge was obtained from the wastewater treatment plant in a dairy industry. All experiments were performed in the batch system and effective parameters such as the pH, adsorbent dosage, and the initial concentration and contact time of Ni ²⁺ and Cr ⁶⁺ were investigated. The adsorption isotherms and kinetics were evaluated to describe the metal uptake and dynamic reactions. Results: The results of this study showed that with an increasing adsorbent dose and contact time, Ni ²⁺ and Cr ⁶⁺ removal efficiency increased. The maximum adsorption of Ni ²⁺ and Cr ⁶⁺ was obtained in pH 6 and 2, respectively. Meanwhile, with increasing Ni ²⁺ and Cr ⁶⁺ concentration, the removal efficiency decreased. The results best fitted the Langmuir isotherm and the maximum absorption capacity of Ni ²⁺ and Cr ⁶⁺ onto dry activated sludge (DAS) were 2.17 and 2.23 mg/g, respectively. Analysis of the adsorption kinetics showed that the intraparticle diffusion kinetic had been good and presented Ni ²⁺ and Cr ⁶⁺ uptake onto DAS, and the intraparticle diffusion rate constant of Ni ²⁺ and Cr ⁶⁺ were 0.044 and 0.042 (mg/g min ^0.5 ), respectively. Conclusions: According to the results, dry activated sludge is suggested as a low cost and available adsorbent for removing Ni ²⁺ and Cr ⁶⁺ from aqueous solutions.

Aims: The aim of this study is to determine the PCE biodegradation potential in an Anaerobic Migrating Blanket Reactor (AMBR) that has not been used so far for the bioremediation of this compound, in high concentration, and to evaluate the system performance. Materials and Methods: This study was an Experimental - Interventional study that was done from April 2010 to March 2011, in the Isfahan University of Medical Sciences. The AMBR was used in a type of laboratory scale, with a volume of 10 L, which was divided into four compartments, for the biological degradation of PCE in a synthetic substrate. The startup was done using anaerobic digested sewage sludge. The performance of the reactor was evaluated during four periods, with a PCE loading rate of 3.75 until 75 mg PCE/L.d. The hydraulic retention time (HRT) was 32 hours. Results: Optimum chemical oxygen demand (COD) removal efficiency was obtained, 98%, with an organic loading rate (OLR) equal to 3.1 g COD/L.d. For PCE removal, the optimum efficiency was observed to be 99.8%, with a PCE loading rate equal to 37.5 mg PCE/L.d. The average COD and PCE removal rates for the whole activity period of the reactor were 91.4 and 99.5%, respectively; 1.1 ± 0.7% from the influent PCE was adsorbed on the biomass and 20% was found in the headspace. Conclusions: The AMBR reactor, which provides full-scale studies and uses real industrial wastewater polluted with PCE, is a simple, efficient, and reliable method for the treatment of PCE.