Scales and sludge are commonly formed during oil and gas extracting and processing operations. They usually appear when injection and formation water with different chemical characteristics come into contact. When the produced water is brought to the surface alongside with the oil, a precipitate can be deposited on the walls of pipes and equipment, forming the so-called scales. Otherwise they c...

The activated sludge process is one of the most important parts of conventional wastewater treatment plants. Wastewater is treated biologically in activated sludge basins. Activated sludge can remove soluble contaminants, primarily organics compounds and nitrogen, from the wastewater stream. The activated sludge is a mixture of microorganisms, inorganic and organic compounds aggregated to flocs...

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...

BACKGROUND Biological activated sludge process must be functionally stable to continuously remove contaminants while relying upon the activity of complex microbial communities. However the dynamics of these communities are as yet poorly understood. A macroecology metric used to quantify community dynamic is the taxa-time relationship (TTR). Although the TTR of animal and plant species has been ...

Wennman, P. 2004. Decomposition and nitrogen transformations in digested sewage sludge applied to mine tailings -effects of temperature, soil moisture, pH and plants. Licentiate thesis. ISSN 1652-4748, ISBN 91-576-6628-8 Applying sewage sludge to mine tailings to encourage growth of vegetation in order to prevent environmental problems such as erosion and leaching of metals began around 1970. U...

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...