The lightweight aggregates used by the civil engineering market are sintered at a high temperature, about 1200 °C. In times of high energy prices and regulation of carbon dioxide emissions, lightweight aggregate products of the high-temperature process in sales marketing are not readily accepted. This study developed a sintered-type paper sludge lightweight aggregate. In order to reduce energy ...

In order to study the performance and mechanisms of excess sludge reduction in the activated sludge that incorporates the Cannibal Process, laboratory activated sludge systems incorporating an anaerobic bioreactor into the sludge recycle stream were operated. In this study, the solids production in the Cannibal system was about 35-40% of the conventional system under steady state conditions. Th...

Activated sludge is widely used to treat municipal and industrial wastewater globally and the formation of activated sludge flocculates (flocs) underpins the ability to separate sludge from treated water. Despite the importance of activated sludge flocs to human civilization there have been precious few attempts to rationally design fit for purpose flocs using a bottom-up approach based on a so...

This work deals with the effect of combined microwave-ultrasonic pretreatment on the anaerobic biodegradability of primary, excess activated and mixed sludge. The characteristics, biodegradability and anaerobic digester performance for untreated primary, excess activated and mixed sludge were compared to combined microwave-ultrasonic pretreated primary, excess activated and mixed sludge. All sl...

The slow degradation rate of sewage sludge in anaerobic digestors is due to the rate limiting step of sludge hydrolysis. The effect of ultrasound pretreatment on sludge degradability was investigated using ultrasound at a frequency of 31 kHz and high acoustic intensities. Ultrasound treatment resulted in raw sludge disintegration as was demonstrated by increase of Chemical Oxygen Demand in the ...

The treatment and disposal of sewage sludge is an expensive and environmentally sensitive problem. It is also a growing problem world-wide since sludge production will continue to increase as new sewage treatment works are built and environmental quality standards become more stringent. With some traditional disposal routes coming under pressure, and others such as sea disposal having been phas...

Sewage sludge was disposed of in Liverpool Bay for over 100 years. Annual amounts increased from 0.5 million tonnes per annum in 1900 to approximately 2 million tonnes per annum by 1995. Macrofauna and a suite of environmental variables were collected at a station adjacent to, and a reference station distant from, the disposal site over 13 years, spanning a pre- (1990-1998) and post- (1999-2003...

This paper critically reviews the fate of trace organic contaminants (TrOCs) in biosolids, with emphasis on identifying operation conditions that impact the accumulation of TrOCs in sludge during conventional wastewater and sludge treatment and assessing the technologies available for TrOC removal from biosolids. The fate of TrOCs during sludge thickening, stabilisation (e.g. aerobic digestion,...

Activated sludge process has been widely adopted to remove pollutants in wastewater treatment plants (WWTPs). However, stable operation of activated sludge process is often compromised by the occurrence of filamentous bulking. The aim of this study is to build a proper model for timely diagnosis and prediction of filamentous sludge bulking in an activated sludge process. This study developed a ...

-Phragmites austrailis have been commonly planted on sludge treatment wetlands due to its high resistance to sludge waste; thus sludge treatment wetlands are commonly referred to as “reed beds”. Phragmites’ aggressive nature and high productivity allow this invasive plant species to form monoculture stands, alter ecosystem processes, outcompete and replace native species. Thus, native alternati...