Sludge production from wastewater treatment process is high, and the disposal of excess sludge will be forbidden in a near future, thus increased attention has been turned to look into potential technology for sludge reduction. The study attempts to review alternative sludge disposal methods, including anaerobic digestion, aerobic digestion and landfills. In these sludge processes, excess sludg...

Waste activated sludge is slower to biodegrade under anaerobic conditions than is primary sludge due to the glycan strands present in microbial cell walls. The use of pre-treatments may help to disrupt cell membranes and improve waste activated sludge biodegradability. In the present study, the effect of ultrasound, low-temperature thermal and alkali pre-treatments on the rheology, hygienizatio...

A new process which attains both excess sludge reduction and phosphorus recovery has been developed. In this paper, characteristics of sludge solubilization by ozone were investigated in batch experiments with sludge taken from an A/O reactor supplied with synthetic sewage and several real wastewater treatment plants. Then, performance of the new developed process was investigated in a laborato...

In activated sludge systems, the sludge settling ability is considered a critical step where filamentous bulking and biomass deflocculation are the most common problems, causing the reduction of the effluent quality. Furthermore, in recent years image processing techniques have been successfully used to elucidate the activated sludge morphology. Keeping that in mind, a program was developed for...

Large volumes of sludge are produced from onsite sanitation systems in densely populated areas (e.g. slums and emergency settlements) and wastewater treatment facilities that contain high amounts of pathogens. There is a need for technological options which can effectively treat the rapidly accumulating sludge under these conditions. This study explored a pilot-scale microwave (MW) based reacto...

Thermal hydrolysis pre-treatment of sludge for anaerobic digestion increases biogas production, enhances volatile solids reduction, and improves dewaterability of digested sludge. This study reports the performance of a thermochemical hydrolysis process (TCHP) that utilizes heat (60°C70 °C) and sodium hydroxide for cell lysis. The objective of this study is to evaluate the impacts of implementi...

Optimised Ammonia Sanitisation of Sewage Sludge Franziska Häfner The usage of sewage sludge as an organic fertiliser offers a way to recycle nutrients and organic matter for a sustainable agriculture. Sewage sludge is rich in plant nutrient like nitrogen, phosphorus, potassium and micronutrients. Concerning the depletion of phosphorus resources, the reuse of sewage ...

An acidophilic, sulfur-oxidizing Acidithiobacillus thiooxidans MET bacterium was isolated from anaerobically digested, dewatered sewage sludge. This bacterium showed sulfur-oxidizing ability at both acidic and neutral conditions, and allowed metal leaching even at a high (130 g L(-1)) sludge solids concentration. We found that low metal leaching efficiency at high solids concentration was mainl...

During advanced biological wastewater treatment, a huge amount of sludge is produced as a by-product of the treatment process. Hence, reuse and recovery of resources and energy from the sludge is a big technological challenge. The processing of sludge produced by Wastewater Treatment Plants (WWTPs) is massive, which takes up a big part of the overall operational costs. In this regard, anaerobic...

the activated sludge process is the most widely used biological wastewater treatment for both domestic and industrial plants in the world. one of the drawbacks of conventional activated sludge (cas) processes is high sludge production. excess sludge treatment and disposal currently represents a rising challenge for wastewater treatment plants (wwtps) due to economic, environmental and regulatio...