1.
Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics.
Li, L, Zhang, J, Lin, J, Liu, J
World journal of microbiology & biotechnology. 2015;(10):1501-15
Abstract
Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted.
2.
[Biological phosphorus removal in sequencing batch reactor without anaerobic phase].
Wang, DB, Li, XM, Yang, Q, Zhang, J, Liu, YL, Liu, X, Jia, B, Zeng, GM, Liao, DX
Huan jing ke xue= Huanjing kexue. 2008;(7):1867-73
Abstract
The performance of phosphorus removal with a sequencing batch reactor was investigated by simulated municipal wastewater. The experimental results showed that phosphorus removal could be achieved in sequencing batch reactor without anaerobic phase, which was conventionally considered as a key phase for phosphorus removal. Phosphorus concentration in the effluent was 1.0 mg x L(-1) below after 4 h aeration, during which pH was 7.0 +/- 0.2. Which indicated the removal rate of phosphorus was above 90% when the COD and phosphorus concentrationof influent were about 400 mg x L(-1), 15-20 mg x L(-1), respectively. Intracellular storage of poly-phosphate (poly-P) was increasing in the aeration after decreasing in first hour aeration (the content of poly-P was 83.034 mg x g(-1) at the beginning of aerobic phase, 79.980 mg x g(-1) in first aeration and 83.086 mg x g(-1) in end), but the energy storage poly-beta-hydroxyalkanoates (PHA) was constant nearly and the content was very low (PHA concentration was about 5 mg x L(-1)). The researches indicated that phosphate could be transformed to poly-P by poly-phosphate-accumulating organisms without anaerobic zone and PHA, biological phosphorus removal was obtained by removing sludge with rich phosphorus, and this phenomenon could not be explained by conventional theory.