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...

In this study duckweed (Lemna gibba) and waste activated sludge (WAS) were co-digested in different proportions with acclimatized anaerobic granular sludge (AAGS) in mesophilic conditions. The aim was to evaluate if the co-digestion could lead to an increased efficiency of methane production compared to digestion of waste activated sludge alone. Results indicate that co-digestion with both duck...

Batch anaerobic digestion tests of primary sludge and waste activated sludge were conducted for a duration of 123 days to determine the ultimate degradability of the sludges. For primary sludges the inert fraction of the particulate COD that was predicted by the wastewater models could be employed to predict their biodegradability under anaerobic conditions. The degradation of waste activated s...

The paper presents the results of two full-scale applications of the anaerobic co-digestion process of waste activated sludge together with the organic fraction of municipal solid wastes. The experiences were carried out at Viareggio and Treviso wastewater treatment plants (Italy). In the first plant, 3 tons per day of source sorted OFMSW were co-digested with waste activated sludge, increasing...

The objective of this study was to investigate the benefits of co-digestion of a sludge-mix of primary sludge (PS)/thickened waste activated sludge (TWAS) with concentrated fat-oil-grease (FOG) over a wide range of FOG/sludge-mix volumetric feed ratios. The biodegradability (i.e., COD to methane conversion) of PS, TWAS, sludge-mix, and FOG was 43.0, 38.6, 41.8, and 97.7%, respectively, with a p...

By the consideration of the microscopic picture of activated sludge samples it is possible to introduce a further biological parameter apart from the conventional physico-chemical parameters for the evaluation and control of biological stages of waste water treatment plants. It is reported that different parameters have certain influences on the activated sludge floc and on the developing bioze...

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...

The purpose of this study is to determine how the rheological characterization of centrifuged thickened waste excess activated sludge (EAS). Wastewater treatment plants (WWTP) contain a number of transport operations of suspensions with special flow characteristics. Flow characteristics, in particular viscosity related effects, vary from very water-like to strongly non-Newtonian. This study use...