The present disposal routes of sewage sludge represent a critical environmental issue in Egypt. Recently, there has been an increasing concern about sewage sludge management due to the environmental risks, which resulted from the fast expansion of wastewater treatment plants without equal attention in dealing with the produced sludge. This paper discusses the current situation of sewage sludge ...

In this study, the occurrence, fractionation, and potential ecological risk associated with seven heavy metals (HMs), i.e., Cd, Cr, Cu, Ni, Pb, Zn Hg in sewage sludge (SS) were investigated. The main aim of study was to conduct first comprehensive analysis HMs SS collected from two municipal wastewater treatment plants (WWTPs) using ultrasonic disintegration (UD) thickened excess aimed at impro...

On-line monitoring of process and wastewater streams optimizes the control of treatment methods by providing early indications of problems that could increase discharges of hazardous compounds to the environment. On-line monitoring is important for the immediate detection and remediation of process upsets in critical streams. The waste flow to the Radioactive Liquid Waste Treatment Facility (RL...

This paper presents three new approaches to reduce excess sludge production in activated sludge systems: 1) modification of conventional activated sludge process with insertion of a sludge holding tank in the sludge return line; 2) chlorination of excess sludge so as to minimize excess sludge production; and 3) utilization of a metabolic uncoupler, 3, 3', 4', 5-Tetrachlorosalicylanilide (TCS) t...

Supercritical CO2 (ScCO2) dewatering is a lumen water expulsion process, in which cycled between atmospheric pressure and supercritical phase results fast of free water. In this study, specimens 100 mm length Eucalyptus exserta F.V. Muell. wood were dewatered using ScCO2, then the un-dewatered dried oven at °C to investigate moisture transfer drying stress. The ScCO2 was very fast. When content...

Municipal sludge contains significant amounts of energy, which can be exploited by the use of anaerobic digestion, combustion or gasification. However, the relatively high moisture content of dewatered biosolids (usually over 80%) and long field experience makes anaerobic digestion the most favourable process for energy production from biosolids. Micro-sieves are novel apparatuses for the remov...

Alternate cycling of sludge in aerobic, anoxic, and anaerobic regimes is a promising strategy that can reduce the sludge yield of conventional activated sludge (CAS) by up to 50% with potentially lower capital and operating cost than physical- and/or chemical-based sludge minimisation techniques. The mechanisms responsible for reducing sludge yield include alterations to cellular metabolism and...

The literature on reduction of excess sludge production by ozonation is summarized. Two sequencing batch reactor experiments where sludge is ozonated for this purpose are performed. The purpose of these is to evaluate the prospects of using ozonation to reduce excess sludge production in two different kinds of sludge. Urban sewage sludge is used in the first, and paper mill sludge in the second...