Appraisal of changes in sewage sludge management

Abstract

A positive energy balance caused by accelerated production of CH 4 and additional financial benefits associated with shorter retention times, reduction in volumes, easier dewatering, enhanced hygiene, etc., are the reasons why most modern wastewater treatment plants are newly equipped with hydrothermal pretreatment units. This study examined how the changes in composition of the pretreated sewage sludge fermentation residues manifested themselves in subsequent processing by pyrolysis, both in terms of technology and financial impacts. It has been found that concentrations of heavy metals and other hazardous inhibitors might increase; however, the overall biotoxicity is lower due to their immobilization in the charred mass. Moreover, charring of the fermentation residues results in significant financial as well as technological benefits.

A Study on Applying Biomass Fraction for Greenhouse Gases Emission Estimation of a Sewage Sludge Incinerator in Korea: A Case Study

“…Generally, the operating cost associated with the sludge handling was often reported to be a significant part of the overall operating cost in the wastewater treatment plant [2]. Also, sewage sludge management is a growing problem, especially in highly populated areas [3]. Consequently, incineration, with its advantages of large sewage sludge weight reduction effects, excellent stability, and transformation of sewage sludge into solid fuel, has come to the fore as an alternative for sewage sludge disposal.…”