Treatment of domestic waste is generally carried out by activated sludge process. The waste solid sludge can be treated by various aerobic and anaerobic treatment processes. Aerobic treatment methods need space and time. Anaerobic treatments have advantages such as space utilization and production of fuel gases such as methane. Up flow anaerobic sludge digester or fluidized bed digester can be ...

Waste activated sludge is slower to biodegrade under anaerobic conditions than is primary sludge due to the glycan strands present in microbial cell walls. The use of pre-treatments may help to disrupt cell membranes and improve waste activated sludge biodegradability. In the present study, the effect of ultrasound, low-temperature thermal and alkali pre-treatments on the rheology, hygienizatio...

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...

background sewage sludge (biosolids) is a byproduct of wastewater treatment that accumulates in large quantities. effective stabilization and disinfection of sewage sludge prior to land application are necessary to not only protect human health, but also to induce the public its benefits and safety. currently, many wastewater treatment plants in iran dispose great amounts of untreated sewage sl...

this research was done in order to determine the basic criteria for “tehran oil refinery effluemt treatmentunit” to prove the feasibility of the application of powdered activated carbon in aeration zone of activated sludge system. the main stages of this research included: determination of qualitative and quantitative characteristics of raw wastewater preparation of two pilot scale units of act...

Denitrification of synthetic high nitrate waste containing 9032 ppm NO(3)-N (40,000 ppm NO(3)) in a time period of only 6h has been achieved in our previous study using activated sludge. The activated sludge culture was acclimatized by a stepwise increase in the nitrate concentration of synthetic waste. In the present work, studies were carried out on the changing microbial population of the sl...

Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days,...

osa (oxic settling anoxic) process is one of the sludge reduction methods. in this method an anaerobic reactor is placed in activated sludge recycling line for sludge reduction purpose. this method is getting popular because of possibility of its application in currently operating waste water treatment plants. in this research, the performance of osa process in sludge reduction in sbr was impro...

there are more than 350 wastewater treatment plants distributed across different parts of oman. some of them produce large quantities of domestic sewage sludge, particularly this study focused on characterizing domestic sludge of six treatment plants that may contain various pollutants, therefore the proper management of domestic sewage sludge is essential.samples of domestic sewage sludge were...