Technology of Sorption Treatment of Sludge from Heavy Metals in Wastewater Treatment Plants in Georgia

Modern urban wastewater treatment methods are conjugated with sludge formation and its rational management. Unlimited accumulation of sludge in wastewater treatment plants (WWTP) may be uneconomic leading to environmental problems. Utilization of sludge is considered a priority task for research and development in this area. Reuse of substances in circulation by recycling and removal of substances from circulation by elimination are the two methods of sludge management. Sludges have various critical properties/components that prevent their direct return to the circulation of substances or their removal from it. As a result, sludge need to be treated to change the critical properties/components so that hazardous impurities no longer have a critical impact on the environment. This study identifies the harmful impurities in sludge. The study explores the technical possibility of extracting the impurities from sludge using some natural sorbents in wastewater purification in WWTP. The study proposed a combined water and sludge purification based on the pumping station of WWTP. A rotating metal carousel-type suspension with specific mesh containers into which a specified amount of zeolite is placed, the renewal of which depends on the amount of sorbent, and the quality of the cushioning of material used. The developed methodology in laboratory conditions using this technology showed a reduction of contents of studied heavy metals in sludge by 30-50%. The study introduces development and testing of an integrated sludge and wastewater treatment system that uses natural sorbents in an innovative mechanical system. This novel approach contributes to addressing economic and environmental challenges associated with sludge accumulation at WWTPs.