| ORIGINAL ARTICLE |
|
| Year : 2020 | Volume
: 9
| Issue : 1 | Page : 2 |
|
|
Biological excess sludge reduction in adsorption/bio-oxidation process by enhancing predators' growth
Somayeh Kheiri1, Ensiyeh Taheri2, Nasim Rafiei3, Ali Fatehizadeh2, Mohammad Ghasemian1, Mohammad Mehdi Amin2, Mohammad Koushafar1, Seyed Mohammad Mousavi4
1 Department of Agriculture Sciences, Islamic Azad University, Ardestan Branch, Ardestan, Iran
2 Department of Environmental Health Engineering, School of Health; Environment Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
3 Environment Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease; Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran
4 Esfahan province Water and Wastewater Company, Isfahan, Iran
Correspondence Address:
Dr. Mohammad Mehdi Amin
Environment Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan
Iran
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/ijehe.ijehe_1_18
|
|
|
Aims: This study was carried out to investigate the effect of predators' growth on biological excess sludge reduction of adsorption/bio-oxidation process (A/B process) as a modification of activated sludge system. Materials and Methods: The real municipal wastewater after screening and gritting was pumped into A/B pilot plant which consists of two aeration and sedimentation tanks in series. The hydraulic residence time for A and B stages was set at 1 and 4 h, respectively, at an average flow rate of 32 L/h. During operation, the mixed liquor suspended solids (MLSS) in A and B stages was gradually increased. In this period, the operational parameters including dissolved oxygen, pH, volatile suspended solids (VSS), MLSS, alkalinity, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), phosphorus, nitrogen, and sludge volume index were monitored. Results: The results showed that with increasing solid retention time (SRT) from 0.6 to 56.8 days in Stage A, the biomass yield (Y) decreased from 1.29 to 0.23 g VSS/g COD. Similar results were observed in Stage B and correspondence to 67% reduction of Y as SRT increased from 1.6 to 123.8 days. During the A/B operation, overall tBOD5and tCOD removal was 70% ± 20% and 57% ± 24%, respectively. Conclusion: Based on the results, A/B process operation with high SRT led to predator growth enhancement and lower biological excess sludge production.
|
|
|
|
| [FULL TEXT] [PDF]* |
|
 |
|
