Thermophilic treatment is one of the advanced treatment technologies used for the purification of high-strength wastewaters. Thermophilic systems are conventionally used for sludge treatment, but their ability to reduce COD to a great extent with sludge generation one-tenth when compared to the other wastewater treatment technologies, have favored its application for wastewater purification. Mo...

Sewage sludge production increases continuously reaching almost 20% (946 700 t 1 118 795 tons of dry matters in 2007) during the (directly or after composting). The remaining 30% was incinerated (with or without household wastes) or landfilled. Nowadays, sludge reduction is a major concern. This activity has to becom be careful to the environmental impacts of sludge treatment and disposal route...

Rheological behaviour of recycled sludge from a secondary clarifier of a municipal wastewater treatment plant was studied by using the rate controlled coaxial cylinder viscometer Rotovisko-Haake 20, system M5-osc., measuring device NV. The tests (hysteresis cycles) were performed under continuous flow conditions and following an ad hoc measurement protocol. Sludge shear stress versus shear rate...

Ultrasound treatment is often applied to enhance the anaerobic digestion of sludge. Optimal conditions for organic matter solubilisation of primary, secondary and mixed sludge were assessed by implementing ultrasound disruption at different specific energies (from 3,500 to 21,000 kJ/kgTS). The variation in soluble chemical oxygen demand (sCOD) and ammonium nitrogen (NH4+-N) was monitored follow...

As important constituents of activated sludge flocs, extracellular polymeric substances (EPS) play significant roles in pollutants adsorption, the formation and maintenance of microbial aggregates, and the protection of microbes from external environmental stresses. In this work, EPS in activated sludge from a municipal wastewater treatment plant (M-WWTP) with anaerobic/anoxic/oxic (A(2)/O) pro...

The treatment of water from paint spray booths in automobile assembly plants typically involves applications of large quantity of chemicals as coagulants and flocculants. Suspended paint solids are brought to water surface in sludge pits after these chemicals are added. The suspended paint particles are then mechanically collected and removed as sludge for further treatment and disposal. There ...

Wastewater treatment plants are one of the main sources of dissemination of antibiotic resistance genes (ARGs) into the environment. The present study was conducted to determine the prevalence and removal of ARGs in different wastewater treatment processes. A total of 36 samples from raw and final effluent of different activated sludge processes were collected and analyzed. Molecular analysis w...

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...

Background: Reprocessing of sewage sludge to agricultural land is preferred to disposal through landfill or incineration due to its potentially beneficial effects on soil fertility from organic matter and plant nutrients, such as N and P, present in the sludge. Therefore, this study was conducted to investigate the impact of sewage sludge and chemical fertilizers on Pb and Cd accumulation in ...

Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is neede...