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 ...

This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sl...

the excess sludge treatment and sludge disposal are major factors to the over-all economy of wastewater treatment plants (wwtp). the ideal solution to the problem of sludge disposal is to combine sludge minimization with contamination removal at the source. in this study, the effect of ozonation, chlorination and 3,3,4,5–tetrachlorosalicylanilide (tcs) to treat part of the return activated slud...

the excess sludge treatment and sludge disposal are major factors to the over-all economy of wastewater treatment plants (wwtp). the ideal solution to the problem of sludge disposal is to combine sludge minimization with contamination removal at the source. in this study, the effect of ozonation, chlorination and 3,3,4,5–tetrachlorosalicylanilide (tcs) to treat part of the return activated slu...

The bacterial community structures in two sewage treatment plants with different processes and performance were investigated by denaturing gradient gel electrophoresis (DGGE) of nested polymerase chain reaction (nested PCR) amplified 16S rRNA gene fragments with group-specific primers. Samples of raw sewage and treated effluents were amplified using the whole-cell PCR method, and the activated ...

Microbial activity measurements (oxygen transfer rate, OTR, carbon dioxide transfer rate CTR and respiratory quotient, RQ) are used to monitor and control biological processes. In this study, the digestion of activated sludge in microaerobic conditions was evaluated. The changes of biological activity during digestion were monitored by respiration activity. The sludge mixtures used were primary...

The activated sludge biodegradability of 12 commercial phthalate esters was evaluated in two test systems: (i) a semicontinuous activated sludge test and (ii) an acclimated 19-day die-away procedure. Both procedures demonstrated that phthalate esters are rapidly biodegraded under activated sludge conditions when loss of the parent phthalate ester (primary degradation) is measured.

Biliary sludge may be a precursor of gall stones in man. The aim of this study was to determine the incidence of biliary sludge in a prospective study of 36 patients admitted to the intensive care unit for longer than two days. The presence of biliary sludge was determined by ultrasonography. Biliary sludge developed in 17 patients (47%), after a mean of 5.5 days in the intensive care unit. Pat...

Activated sludge gains xenobiotic degradation capability through acclimation to the target. Acclimated activated sludge contains a two-part biomass of non-degrader and degrader, abundance of the latter being most important for activated sludge to successfully treat the inflow of xenobiotic pollutants. For the purposes of understanding and also possible improvement of xenobiotic treatment, xenob...

BACKGROUND In this study, a hybrid treatment system (Fluidized Bed positioned in a biological reactor of an Activated Sludge process) was used to treat saline domestic wastewater. The performance of the mentioned hybrid system was compared with the conventional activated sludge. A pilot study was conducted, and Chemical Oxygen Demand (COD), Electrical Conductivity (EC), Total Dissolved Solids (...