In activated sludge systems, the sludge settling ability is considered a critical step where filamentous bulking and biomass deflocculation are the most common problems, causing the reduction of the effluent quality. Furthermore, in recent years image processing techniques have been successfully used to elucidate the activated sludge morphology. Keeping that in mind, a program was developed for...

Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier transform infrared (FTIR) spectroscopy technique. The results showed that the aerobic g...

Although the activated sludge process for stabilizing liquid organic wastes is primarily a biological process, very little research has been conducted on the pure biological phases of this process. Until the work of Butterfield (1935), activated sludge was considered by some as a physio-chemical process and by others as a bio-chemical process. Butterfield isolated a bacterium, Zoogloea ramigera...

Toxic compounds in sewage or industrial wastewater may inhibit the biological activity of activated sludge impairing the treatment process. This paper evaluates the Inhibition Capacity Index (ICI) for the assessment of activated sludge in the presence of toxicants. In this study, activated sludge was obtained from industrial treatment plants and was also synthetically produced. Continuous respi...

Assessment of protozoan populations is an important tool in evaluating the efficiency of activated sludge in the treatment of wastewater. In this process, protozoa play a significant role by grazing on dispersed bacteria, supporting a healthy food web in activated sludge artificial ecosystems. The objective of this study was to verify how the success of the purification process in activated slu...

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...

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....