the activated sludge process is the most used biological wastewater treatment method in the world. sludge bulking is one of the most common problems relateing to activated sludge wastewater treatment, and this fact causes poor settling in secondary sedimentation tank. sludge volume index(svi) and the zone settling velocity(zsv) are parameters to quantify the settleability of activated sludge . ...

Background: In this study, the effect of wastewater produced by pistachio processing in processing terminals on wastewater treatment plants with activated sludge process was investigated. Methods: The pilot of activated sludge was constructed at the laboratory scale similar to wastewater treatment plant in Kerman and it was investigated in different ratios of the wastewater of pistachio proces...

The effect of raw and anaerobically digested sludge on heat inactivation of poliovirus was investigated. Raw sludge was found to be very protective of poliovirus plaque-forming ability at all temperatures studied, but digested sludge had variable effects that were highly dependent upon the experimental conditions. In low concentrations and at relatively low inactivation temperatures, digested s...

Oxic-settling-anaerobic process (OSA) was known as a cost-effective way to reduce the excess sludge production with simple upgrade of conventional activated sludge process (CAS). A low oxidation-reduction potential (ORP) level was the key factor to sludge decay and lysis in the sludge holding tank of the OSA process. However, the ORP control with nitrogen purge or chemical dosing in the OSA pro...

results the results of this study showed that the release of soluble chemical oxygen demand (scod) in the supernatant and srf were in the range of 127.9-831 mg/l and 12.48-36.55 m/kg at 10 to 120 min ultrasonic contact time, respectively. in addition, ts and vs decreased from 57.98 and 56.31 to 52.69 and 49.87 mg/l, respectively. despite the significant reduction in the solids, there was no con...

aims: in biological wastewater treatment processes, a large amount of sludge is produced. stabilization of sludge is essential before disposal because of the risks to human health and environment. therefore, selecting an appropriate process for stabilization this sludge may efficiently decrease risks. the aim of this study was to examine the compound efficiency of the advanced fenton and ozonat...

background: domestic and industrial wastewaters are mostly treated by biological process such as activated sludge, aerobic pond, and anaerobic treatment. this study focuses on characterizing the quality of sewage sludge in the sultanate of oman chosen from three industrial sewage treatment plants (stps): rusayl industrial estate (rsl.ie); sohar industrial estate (sie); and raysut industrial est...

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...

sewage sludge with having the organic matter is considered as a source of micro and macro elements. in order to investigate the effect of different levels and period of application of sewage sludge (ss) on organic matter, respiration, and acid and alkaline phosphatase activity, factorial design were studied, in 3 replications. sewage sludge at five levels, (20 and 40 tons of sewage sludge, 20 a...