The treatment of liquid wastes in municipal sewage treatment plants creates significant quantities of solid residue for disposal. The potential hazard from these wastes requires that their characteristics be determined accurately to develop environmentally sound management criteria. It is readily recognized that the sludge characteristics vary with the type and degree of industrial activity wit...

Autothermal thermophilic aerobic digestion (ATAD) is a promising process for sewage sludge stabilization. Batch experiments were conducted on sewage sludge collected from a municipal wastewater treatment plant in Shanghai, China, to evaluate the effectiveness of the ATAD system by determining changes in volatile suspended solids (VSSs) and to study its microbial diversity by denaturing gradient...

Resource reuse of waste-activated sludge (WAS) from a municipal wastewater treatment plant (WWTP) was introduced as raw material of microbial flocculant (MBF) preparation. With WAS samples of three concentrations, MBF preparation by various methods – including cation exchange resin (CER), CER-ultrasonication, CER-ultrasonication-CER, ultrasonication, ultrasonication-CER, and ultrasonication-CER...

-In this paper, a low-order linear timeinvariant (LTI) state-space model that describes the nitrate concentrations in both anoxic and aerobic zones of an activated sludge wastewater treatment plant (WWTP), for biological treatment of municipal sewage, is identified around a given operating point (a model with lumped parameters). Several subspace identification methods, such as CCA, N4SID, MOESP...

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR). Control of membrane fouling can extend the membrane life and reduce water treatment cost effectively. A pilot scale anoxic/aerobic-membrane bioreactor (A/O-MBR, 40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin, China. Impact factors including mixed liquid ...

When the sewage sludge containing the persistent, lipophilic, metabolite 4-nonylphenol (4-NP) has been disposed of in the environment it's toxic nature can lead to serious health risks to human beings and can also affect plants and aquatic organisms. Supercritical fluid extraction (SFE) is a new and powerful technique for extracting the organic contaminants from the solid phase. The present stu...

The performance of an anaerobic digestion fed with waste activated sludge (WAS) pretreated with NaOH was examined. The sludge was periodically collected from a municipal wastewater-treatment plant. The laboratory work was run in four 1-1 semi-continuous anaerobic digestion reactors. Reactor A was fed with untreated WAS at 1% total solids (TS). The other three reactors, B, C and D, were respecti...

Anaerobic digestion (AD) is a process by which microorganisms break down biodegradable material in the absence of oxygen. Anaerobic digestion can be used to treat various organic wastes and recover bio-energy in the form of biogas, which consists mainly of CH4 and CO2. A great option for improving yields of anaerobic digestion of solid wastes is the co-digestion of multiple substrates. Numerous...

This study examined a novel reuse of alum sludge, an inescapable by-product of drinking water treatment process when aluminium salt is added as a coagulant, as the main medium in a laboratory-scale multi-stage constructed wetland (CW) system for reject water treatment. Such reject water is a main concern in municipal wastewater treatment plant (MWWTP) for increasing the organic and nutrient loa...

Extracellular polymeric substances (EPSs) were extracted by high-speed centrifugation at 20,000 G for 30 min from an activated sludge treating municipal wastewater. Each gram of sludge, as measured in volatile suspended solids (VSS), contained 7.3 mg of EPS, including 6.5 mg of protein (EPSp) and 0.8 mg of carbohydrate (EPSc). The EPSp had a mean MW of 2.0 x 105; about 18% of EPSp had MW over 5...