Determination of the distribution of pollutants in the sludge content among the phases formed after the electro-dewatering process

The world faces major challenges such as the energy crisis, food shortage, and hazardous waste production which lead to difficulties in socio-economic relations and prevent environmental sustainability. The fast-developing technology and urbanization bring waste generation as well. This causes an increase in the number and need for WWTPs. Treating wastewater comes up with huge amounts of waste activated sludge as a by-product. The sludge not only consists of high amounts of water and harmful pathogens but also contains a source of various essential materials and nutrients. In last years, electrochemical processes have been called an effective technique for sludge dewatering and resource recovery. Since the electro-dewatering (ED) process significantly reduces sludge volume by separating free and bound water from the sludge matrix, it becomes a more cost-effective and sustainable sludge management. After the ED process, the raw sludge divides into three (3) outputs; filtrate (1), dewatered sludge (2), and volatile (gas) phase (3). Nevertheless, this gas volume and its characterization are ignored in the literature studies. In this thesis, the fate of linear and cyclic volatile methyl siloxanes, the toxic heavy metal compounds of Cu, Cd, Pb, Zn, and inorganic odorous gases of H2S and NH3 compounds were pointed out during the ED process. Box-Behnken Statistical Analysis was used to determine optimum operating conditions in the ED reactor processing. Once the voltage and pressure values are applied, besides the efficient solid-liquid separation, the gas release from the reactor is calculated in the range of 9% to 25%. Emission fluxes and emission factors were produced. At the end of the process, the removal rate of UMS and heavy metal compounds was found as 40% to 70% from the raw sludge while the pollutant gases were found to be released in the range of 30% to 60% into the atmosphere. Hence, the positive and negative aspects of this technology in terms of the contribution of the ED process to sludge management and atmospheric pollution were determined.