Aim: Hydrogen sulfide is one of the most harmful substances known in the drilling industry. Hydrogen sulfide can cause health, environmental, safety, and damage to property problems. Therefore, we conducted this study on a laboratory scale to make carboxylated carbon nanotubes and investigate their performance in removing hydrogen sulfide from drilling mud. Materials and Methods: In the first step, we prepared multi-walled carbon nanotubes with 90%–95% purity. In the next step, we provide the drilling fluid. The fluid used in these experiments was a simple water-based mud consisting of water and bentonite. In the last step, we used the Qualitek-4 software to design experiments, and the Taguchi model was used to investigate the obtained results. Results: Results show that pH is the most effective parameter in the adsorption process. Interaction of adsorbent concentration with retention time shows the highest SI = 85.85%. Optimal conditions of H2S adsorption are adsorbent concentration = 100 ppm, pH = 6, and retention time = 30 min. According to the Langmuir model, the adsorption capacity of carbon nanotube (CNT)-COOH was 2480 (mg/mg). By increasing CNT-COOH concentration from 50 ppm to 100 ppm, the adsorption percent of H2S increased from 51.6% to 66.1%. By increasing the retention time from 2 min to 30 min, an increase in adsorption will be seen from 57.5% to 65.3%. Conclusion: Using functionalized nanocarbon tube with at least 90% efficiency is a reliable method to remove hydrogen sulfide from drilling mud.

Introduction: In addition to having auditory effects, sound also has nonauditory effects. Acoustic Annoyance is one of the nonauditory effects of sounds which are construed as psychoacoustic characteristics. The study at hand was undertaken to investigate the psychoacoustic characteristics of absorbents used in common earmuffs. Materials and Methods: In this study, four earmuffs prevalent in industries were used. The psychoacoustic characteristics of loudness and sharpness were measured and analyzed in sound levels of 75, 85, and 95 dB using an impedance tube and Va-Lab 4 software with and without absorbers. The results were analyzed with SPSS-26 software. Results: Results showed that the highest and the lowest increase in loudness were attributed to the EM-101 and the EM-104, respectively. In addition, with the increase in the sound level, the loudness increased. Furthermore, in 85 dB, there was no significant relationship between loudness and earmuff absorber only in the case of the earmuff EM-103. Furthermore, the highest and the lowest increase in sharpness were, respectively, attributed to the EM-101 and the EM-103. Only in the samples of EM-103 and EM-104 earmuffs at the level of 75 dB, there was no significant relationship between sharpness and earmuff absorber. Conclusion: Earmuffs used in industries showed different performances against the loudness and sharpness of the sound. In other words, the quality and the structure of earmuff absorber play noteworthy roles in decreasing the qualitative parameters of sound.

Aim: The presence of Fe and Mn content in water, apart from being able to interfere with health, also creates a metallic taste and odor of drinking water and causes a yellow color on the walls and clothes. Thus, it is necessary to use appropriate and effective technologies to lower the amounts of iron and manganese in water. The technology involves the use of Filtration Media for Iron (Fe) and Manganese (Mn) Content in Drilling Wells, including Zeolite, Ferolite, and Manganese Greensand. Materials and Methods: The first treatment was for control, and the second, third, fourth, and fifth treatments, each containing zeolite ferrolite, and Mn media and the combination of media, were for the filtration process and repeated four times. Results: The results showed that the use of zeolite, ferrolite, and Mn filter media and the combination of media was able to increase Fe level by 11.05%, 5.99%, 21.78%, and 40.98%, respectively. Meanwhile, the use of zeolite, ferrolite, and Mn and the combination of media was able to reduce Mn level by 35.58%, 44.97%, 48.30%, and 75.28%, respectively. Conclusion: It is not recommended to use zeolite, ferrolite, and Mn filter media for processing Fe in borehole water. Zeolite, ferrolite, and Mn filter media can be used to reduce Mn levels in the borehole water.

Aim: This study aimed to verify the general health status and its related factors of medical staff during the COVID-19 pandemic in Daran Shahid Rajaee Hospital. Materials and Methods: This cross-sectional study was performed by census method on 168 medical staff in Shahid Rajaee Hospital in Daran city during the COVID-19 pandemic. Data were gathered by applying a questionnaire, containing demographic information and a 28-item standard General Health Questionnaire. Eventually, data analysis was performed by Spearman correlation tests and the Mann-Whitney U and Kruskal–Wallis H tests, using the SPSS software V.26. Results: The results of the study revealed that the general health score, among the individuals, was at a healthy level with a mean of 20.77 ± 11.8. Spearman correlation test represented a significant interdependency between age and general health and its connected factors, Somatic Symptoms Scale, and depression symptoms scale (P < 0.05) (R = −0.226, R = −0.174, R = −0.168). In addition, a significant correlation was found between the depression symptoms scale and work experience (P = 0.005) (R = −0.214). Based on the results of the Kruskal–Wallis H tests, a statistically significant difference was found between the employment status and the general health (P = 0.04) as well as the depression symptoms scale (P = 0.019). Conclusion: In this study, the most vital factors affecting both job efficiency and general health were the variables of age, work experience, and type of employment. Furthermore, the subscales of somatic symptoms and depression symptoms were identified as the most effective subscales on general health.

Aim: The present study seeks to help the experts and specialists by investigating documents relevant to the harmful chemical compounds and toxic substances used in the production processes of a few novel industries so that, the information gap is identified by recognizing such toxicants and taking steps to fill such gap. Methods: By making the use of keywords related to the objective of the study (keywords such as toxicity, modern toxicity, modern industries (MIs), new toxins, modern/new chemical compounds), the indexed articles were searched from 2000 to 2022 in ProQuest, Science Direct, Pub Med, Scopus, Web of Science, and Google Scholar databases aiming at access to the toxic compounds in several MIs. In this study, out of 116 articles searched as full text and following the inclusion and exclusion criteria, 46 articles were wholly selected. Results: According to the results, the issues include the nanotechnology industry (silver-nanoparticles, gold-nanoparticles, titanium dioxide, zinc-oxide, cerium-dioxide, and iron-oxide nanoparticles), nuclear technology (cobalt [60 Co and 58 Co], uranium [235U], and plutonium [Pu4+]), semiconductor industries (arsenic compounds, phosphorus, dopants, acids, photoactive compounds, etc.), liquid crystal display industries (indium compounds and indium tin oxide), pharmaceutical and medical (cytotoxic and platinum-based drugs), modern dentistry (resins, silica-nanofillers, barium-glass, and beryllium compounds), as well as the MIs involved in silica, nickel, and dioxin nanoparticles, were documented and discussed. Conclusion: Developing MIs and equipping the traditional industries with new technologies have confronted humankind with different chemicals and toxins resulting from producing and using products that require attention, study, and research. It is hoped that the present review study will pave the way for extensive studies on occupational health and toxicology in MIs.