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...

BACKGROUND The recalcitrant cell walls of microalgae may limit their digestibility for bioenergy production. Considering that cellulose contributes to the cell wall recalcitrance of the microalgae Chlorella vulgaris, this study investigated bioaugmentation with a cellulolytic and hydrogenogenic bacterium, Clostridium thermocellum, at different inoculum ratios as a possible method to improve CH4...

This study compared the PHAs production behavior of sludges from the anaerobic and oxic phases of an enhanced biological phosphorus removal (EBPR) system. This was accomplished by using the kinetics and stoichiometric coefficients obtained from aerobic batch tests to evaluate the performance of these two sludges. Experimental results indicated that the metabolic behavior of the sludges for PHAs...

A four-month study was conducted in a greenhouse with Larix laricina grown on sand and nursery soil. This culture was fertilized with anaerobically digested sludge at various rates and doses. No direct relationship could be established between the growth of seedlings and the quantities of sludge applied. Relationships were, however, established between the quantities of sludge applied and the e...

This paper aimed at analysing the current state of methods increasing methane generation during treatment organic sewage sludge. The authors considered theoretical principles biogas production and main directions intensification fermentation processes. A chemical study sediments produced plants in city Kharkiv, Ukraine, showed that C/N ratio investigated excess activated sludge is 4–5, mixture ...

Anaerobic digestion (AD) has long been used to treat different types of organic wastes especially in the developed world. However, organic wastes are still more often considered as a waste instead of a resource in the developing world, which contributes to environmental pollution arising from their disposal. This study has been conducted at Bugolobi Sewage Treatment Plant (BSTP), where two orga...

Ultrasonic treatment of waste activated sludge is one of the possibilities to reduce excess sludge production through the mechanism of sludge disintegration and cell lysis. In the past, several attempts have been made to model the process of solubilisation of the particulate volatile suspended solid part of the activated sludge (VSS) into soluble COD (sCOD). However, the focus of these models w...

BACKGROUND Biohythane is a new and high-value transportation fuel present as a mixture of biomethane and biohydrogen. It has been produced from different organic matters using anaerobic digestion. Bioenergy can be recovered from waste activated sludge through methane production during anaerobic digestion, but energy yield is often insufficient to sludge disposal. Microbial electrolysis cell (ME...