Ultrasonic Alkaline Pretreatment of Biological Activated Sludge from Wastewater Treatment Plants

Contribution to dynamic simulation of activated sludge wastewater treatment plants

In Portugal, many wastewater treatment plants are presently operated according to predetermined schemes, with few concerns to variations of the activated sludge process and without optimizing its performance to achieve a better effluent quality. Little attention has been given to the activated sludge models as powerful tools for wastewater treatment process understanding, design, control and op...

Biological Treatment of Tannery Wastewater Using Activated Sludge Process

A study was conducted to evaluate the feasibility of Activated Sludge Process (ASP) for the treatment of tannery wastewater and to develop a simple design criteria under local conditions. A bench scale model comprising of an aeration tank and final clarifier was used for this purpose. The model was operated continuously for 267 days. Settled tannery wastewater was used as influent to the aerati...

Tetracycline resistance genes in activated sludge wastewater treatment plants.

The development and proliferation of antibiotic resistance in pathogenic, commensal, and environmental microorganisms is a major public health concern. The extent to which human activities contribute to the maintenance of environmental reservoirs of antibiotic resistance is poorly understood. In the current study, wastewater treatment plants (WWTPs) were investigated as possible sources of tetr...

Ultrasonic sludge pretreatment under pressure.

The objective of this work was to optimize the ultrasound (US) pretreatment of sludge. Three types of sewage sludge were examined: mixed, secondary and secondary after partial methanisation ("digested" sludge). Thereby, several main process parameters were varied separately or simultaneously: stirrer speed, total solid content of sludge (TS), thermal operating conditions (adiabatic vs. isotherm...

Ammonia Wastewater Treatment by Immobilized Activated Sludge