Fouling in membrane bioreactors used in wastewater treatment

Ultrasonic pretreatment of sludge: A review

A review of applications of cavitation in biochemical engineering/biotechnology

Municipal wastewater sludge, particularly waste activated sludge (WAS), is more difficult to digest than primary solids due to a rate-limiting cell lysis step. The cell wall and the membrane of prokaryotes are composed of complex organic materials such as peptidoglycan, teichoic acids, and complex polysaccharides, which are not readily biodegradable. Physical pretreatment, particularly ultrasonics, is emerging as a popular method for WAS disintegration. The exposure of the microbial cells to ultrasound energy ruptures the cell wall and membrane and releases the intracellular organics in the bulk solution, which enhances the overall digestibility. This review article summarizes the major findings of ultrasonic application in WAS disintegration, and elucidates the impacts of sonic treatment on both aerobic and anaerobic digestion. This review also touches on some basics of ultrasonics, different methods of quantifying ultrasonic efficacy, and some engineering aspects of ultrasonics as applied to biological ...

Ultrasound Applications in Wastewater Sludge Pretreatment: A Review

http://sourcedb.xtbg.cas.cn/zw/lw/201312/P020131220579561830195.pdf

Ultrasound-enhanced conversion of biomass to biofuels

A review on the dewaterability of bio-sludge and ultrasound pretreatment.

Ultrasonic treatment on activated sewage sludge from petro-plant for reduction.

The invention relates to a excess sludge decrement processing technique. The technical project in said invention is to apply acoustic field to sludge disposal process to come up to the aim of accelerating sludge dewatering, anaerobic digesting and sludge decrement finally. The excess sludge in petrochemical factory is concentrated for 24h (the sludge moisture percentage is 96uNi½98uN), radiated by proper ultrasonic field and then divided into two paths: Firstly, add flocculating agent directly, dewater, fill; secondly, add flocculating agent and dewater after the sludge enters anaerobic digestion devices and most of the organic substances in sludge is digested. The invention decreases the volume of sludge and concentration of organic substances in sludge, reduces the pressure of handling excess sludge.

Xuan Yin

Papers

A review on the dewaterability of bio-sludge and ultrasound pretreatment.

Ultrasonic treatment on activated sewage sludge from petro-plant for reduction.

Process for facilitating sludge decrement