Although activated sludge communities are considered stable, the presence of toxic substances, such as Cr(VI), in the influent may induce changes in the activity and the performance of a wastewater treatment plant. The main objective of this study was the determination of Cr(VI) effects on the performance and on the protistan community of an activated sludge. Six laboratory scale activated slud...

organic fraction of solid waste, which upon degradation produces foul smell and generates pathogens, if not properly managed. composting is not a method of waste disposal but it is a method of waste recycling and used for agricultural purposes. an integrated approach of composting methodology was tested for municipal solid waste management. solid waste first was composted and after 22 days, was...

Sludge minimization by thermal treatment within activated sludge process was investigated at pilot scale. A 90°C treatment was set up in the return activated sludge loop. When keeping apparent sludge age at 15 days, 90°C treatment decreased sludge production by 30.4%. However, effluent quality was altered. A sludge minimization ASM1 based model was set up and calibrated against experimental dat...

Two-level controllers for dissolved oxygen reference trajectory tracking for activated sludge processes is proposed and investigated. Both the nutrient and the phosphorous removal from a wastewater by its biological treatment using an activated sludge technology are considered. Typically, an aeration system itself is a complicated hybrid nonlinear dynamical system with faster dynamics compared ...

micro flora of the effluents from a dairy factory in tehran(pegah dairy processing plant) were isolated and screened for their ability to reduce the organic matter content and cod of the effluents. 10 bacteria were selected due to  reduction in cod content from the 4th to 6th day of incubation at 30 °c and  ph =11. highest cod reduction were obtained by two isolates, bp3 and bp4, 70.7 % and 69....

in this study, activated sludge process for wastewater treatment in a refinery was investigated. for such purpose, a laboratory scale rig was built. the effect of several parameters such as temperature, residence time, effect of leca (filling-in percentage of the reactor by leca) and uv radiation on cod removal efficiency were experimentally examined. maximum cod removal efficiency was obtained...

Activated sludge treatment is one of the most popular biological processes for wastewater treatment. Detection of activated sludge structures from complex substrates such as soil and water is not easy. A rapid and effective method for extracting high molecular weight amplifiable DNA from activated sludge was modified. Five nanogram quantities of DNA per milligram activated sludge were recovered...

The effects of microwave pretreatment on disintegration and mesophilic digestion of waste activated sludge (WAS), primary sludge (PS), combined (PS + WAS) sequencing batch reactor (SBR) sludge and anaerobically digested biocake were investigated by both household and bench scale industrial types microwaves at temperatures below and above boiling point. Pretreatment variables, temperature, inten...