Modern Technologies of Treatment and Stabilization for Sewage Sludge from Water Treatment Plant

Abstract

Abstract In this paper we propose to make an overview of modern technologies for sewage sludge treatment collected from municipal wastewater treatment plants. The topic became important in juncture of fast growth of water supply and sewerage networks and higher water consumption. In the same time substantial changes in the Romanian legislation have been made in order to become harmonized with EU environmental legislation. Whatever water treatment technology is used there are certain methods to settle the obtained sludge: thickening, dewatering, stabilization, conditioning, thermal sludge reduction. Integrated Pollution Prevention and Control concept is the base of European regulations, also defined by the best available technique adopted for sewage sludge treatment that make possible a better management of achievable emission values/ performance rate concerning sludge quantities obtained connecting with greenhouse gas emissions, as well as the extension of treated sludge utilization in agriculture, forestry, soil amelioration, energy recovery. Some of those technologies could be considered new in Romania facing the reality of sewage sludge disposal settlement. Some technologies as e.g. for sludge stabilization and conditioning need previous treatments of sludge as dewatering or thickening. Therefore, for environmental reasons we focus on the following sludge treatment methods: composting, biodigestion and incineration/co-incineration.