This paper critically reviews the fate of trace organic contaminants (TrOCs) in biosolids, with emphasis on identifying operation conditions that impact the accumulation of TrOCs in sludge during conventional wastewater and sludge treatment and assessing the technologies available for TrOC removal from biosolids. The fate of TrOCs during sludge thickening, stabilisation (e.g. aerobic digestion,...

Activated sludge process has been widely adopted to remove pollutants in wastewater treatment plants (WWTPs). However, stable operation of activated sludge process is often compromised by the occurrence of filamentous bulking. The aim of this study is to build a proper model for timely diagnosis and prediction of filamentous sludge bulking in an activated sludge process. This study developed a ...

-Phragmites austrailis have been commonly planted on sludge treatment wetlands due to its high resistance to sludge waste; thus sludge treatment wetlands are commonly referred to as “reed beds”. Phragmites’ aggressive nature and high productivity allow this invasive plant species to form monoculture stands, alter ecosystem processes, outcompete and replace native species. Thus, native alternati...

polyhydroxyalkanoates (phas) are naturally occurring polyester that can be accumulated in bacterial cells as a carbon and energy storage compound. they are metabolized by many microorganisms. these biopolymers accumulate in microbial cells under stress conditions such as limitation of nitrogen, phosphate, sulfur, oxygen, and excess carbon source. currently, phas have attracted increasing intere...

The fate and behavior of estrogenic substances in various biological wastewater treatment processes and several advanced sewage treatment processes were examined. The removal of 17beta-estradiol (E2), estrone (E1) and estriol (E3) was investigated by using a pilot-scale activated sludge plant supplied with domestic sewage. Several sewage treatment plants adopting the activated sludge process we...

Large volumes of sludge are produced from onsite sanitation systems in densely populated areas (e.g. slums and emergency settlements) and wastewater treatment facilities that contain high amounts of pathogens. There is a need for technological options which can effectively treat the rapidly accumulating sludge under these conditions. This study explored a pilot-scale microwave (MW) based reacto...

Anaerobic digestibility of the waste activated sludge (WAS) discharged from large-scale membrane bioreactors (MBRs) and conventional activated sludge processes (CASs) were compared using batch trials. Four wastewater treatment plants were sampled. Results showed that the sludge from MBRs had poor anaerobic digestibility as it had lower volatile solid (VS) reduction rate and lower maximum biogas...

A membrane bioreactor (MBR) and an activated sludge process (ASP) were operated side by side to evaluate the change of sludge supernatant characteristics and the evolution of the sludge fouling propensity. The MBR sludge had a higher organic concentration and more biopolymer clusters (BPC) in the supernatant compared with ASP. BPC increased in both concentration and size in the MBR. The results...

This study combines a two-phase biological treatment system of activated sludge/contact aeration process by adding biological contact filters into the rear sector of the activated sludge aeration tank of the slaughterhouse wastewater treatment plant. This system keeps the advantages of complete mixing of substrates and microorganisms and flexible operation of the activated sludge process, and i...