A filtration devise was developed to assess compressibility of fouling layers in membrane bioreactors. The system consists of a flat sheet membrane with air scouring operated at constant transmembrane pressure to assess the influence of pressure on resistance of fouling layers. By fitting a mathematical model, three model parameters were obtained; a back transport parameter describing the kinet...

Membrane Bioreactor (MBR) process consists of a biological reactor integrated with membranes that combine clarification and filtration of an activated sludge process into a simplified, single step process. The membrane is an absolute barrier to suspended matter and microorganisms and it offers the possibility of operating the system at high mixed liquor suspended solids (MLSS) concentration. Th...

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,...

The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS), play vital roles in the normal operation of wastewater treatment plants (WWTPs). The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on acti...

From a theoretical investigation of the continuity of wastewater organic (COD) and N compounds along the links connecting the primary settling tank (PST), fully aerobic or N removal activated sludge (AS) treating raw and settled wastewater and aerobic digestion unit operations, it was found that the PS characteristics, viz. the biodegradable and unbiodegradable soluble and particulate COD and N...

Henry’s law constant is an important equilibrium factor in the mass transfer process of volatile organic compounds (VOCs). A single equilibration technique (SET) was adopted to measure the air-water dimensionless (KH) and the dimensionless apparent (K’H) of Henry’s law constant in an air-wastewater system and air-activated sludge for VOCs at 298 K. Hydrophilic VOCs (methanol, isopropanol and ac...

Henry’s law constant is an important equilibrium factor in volatile organic compounds (VOCs) mass transfer process. The air-water dimensionless Henry’s law constants (KH) and the dimensionless apparent Henry’s law constants (K’H) in air-activated sludge mixed liquor and air-wastewater system for volatile organic compounds (VOCs) were measured at 298K. Hydrophilic VOCs (isopropanol and acetone) ...

Phenolic compounds cause problems for conventional treatments due to their toxic and inhibitory properties. This work investigated the treatability of phenolic compounds by using two membrane-bioreactor systems, namely: activated sludge coupled with MBR (AS-MBR) and biological granular activated carbon coupled with MBR (BAC-MBR). Initially, the system was fed with phenol (500 mg/L) followed by ...

Ipclass – an interactive program for calibrating activated sludge systems – is formulated and demonstrated. The model involves a heuristic screening algorithm for exploring the system's equations structure, analytical computations of the sensitivities of the variables to the model coefficients, analytical computations of the gradients of the objective functions selected for the calibration proc...