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...

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...