Municipal wastewater sludges are complex fluids displaying non-Newtonian characteristics. Whilst rheological properties of sludges are very important for the design and operation of wastewater treatment facilities, there is a lack of information regarding these properties, particularly for mixtures of primary and secondary sludges. The rheology of wastewater treatment sludge has been widely stu...

aims: intensification of current environmental legislation leads to an increase wastewater treatment sludge volume. so reducing the sludge volume is considered as a strategy to improve and solve the problems of secondary pollution of sludge. dissolved air flotation (daf) as a substitute clarifier is used for separation of activated sludge liquid-solid phases. the aim of this study was to estima...

The management of wastewater sludge, now often referred to as biosolids, accounts for a major portion of the cost of the wastewater treatment process and represents significant technical challenges. In many wastewater treatment facilities, the bottleneck of the sludge handling system is the dewatering operation. Advanced sludge treatment (AST) processes have been developed in order to improve s...

Activated Sludge Treatment is a biological wastewater treatment process which speeds up waste decomposition by adding Activated sludge into wastewater, and the mixture is aerated and agitated for a specified amount of time there by allowing the activated sludge to settle out by sedimentation and is disposed of (wasted) or reused (returned to the aeration tank). It is to everyone’s advantage for...

A mesocosm experiment to assess the fate and effects of sewage sludge in the coastal marine environment was conducted over 4 mo during the summer of 1984 with 9 different treatments of sewage sludge and nutrient addtions. Evidence from setthng rate studes, accumulahons of carbon and pollutant organics and rahos of in the sediment indicated up to 83 O/O of the sludge particulate inputs settled t...

Free nitrous acid (FNA) serving as a pretreatment is an effective approach to accelerate sludge disintegration. Also, sodium dodecylbenzene sulfonate (SDBS), a type of surfactants, has been determined at significant levels in sewage sludge, which thereby affects the characteristics of sludge. Both FNA pretreatment and sludge SDBS levels can affect short-chain fatty acid (SCFA) generation from s...

This article describes a research attempt to integrate the dewatered alum sludge, a residual by-product of drinking water treatment process, into a constructed wetland (CW) system for the purpose of enhancing the wastewater treatment performance, thus developing a so called alum sludge-based constructed wetland system. A multi-dimensional research project including the batch tests of phosphorus...

This study developed a method for analysis of nineteen quinolone and fluoroquinolone antibiotics (FQs) in sludge samples, and investigated the occurrence and fate of the FQs in a municipal sewage treatment plant (STP) with anaerobic, anoxic, and aerobic treatment processes. Eleven compounds, including pipemidic acid, fleroxacin, ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, lomefloxacin,...

Enzymes are important in biological wastewater treatment systems, since they are responsible for breakdown of macro- and micropollutants, thereby making the pollutants available for metabolism. Enzyme activity has been investigated in particular in activated sludge processes, since the activated sludge technology is the most important and widely spread wastewater treatment technology used today...

ACTIVATED sludge processes are the dominating wastewater treatment method. Large quantities of hazardous excess sludge are generated in the processes, and elimination of the waste sludge has been a major problem for the last decade worldwide. The disposal of waste sludge is subject to various environmental, social and economic problems; and the cost consists about 50% of the operational cost of...