Determination of the Feasibility of a Renewed Approach to the Mechanical Cleaning Stage in Wastewater Treatment Plant: A Laboratory Study

Growing population and industrial complexes require municipalities to initiate costly upgrades of their wastewater treatment facilities in order to protect the environment and nearby water bodies. This research project explores if a process combination of centrifugation, flocculation and filtration could increase the treatment capability of a wastewater treatment plant. For all wastewater samples the first process step of centrifugation decreased the total solids content by 23.5%, the chemical oxygen demand between 5.0% and 30.0%, and the total phosphorus content by 20.7% and 32.1% in the supernatant. Flocculation with Ca(OH)2, FeCl3 and Al2(SO4)3 followed by centrifugation increases the solids content of the supernatant, but decreased the chemical oxygen demand and total phosphorus content of up to 55.0% and 95% respectively. Filtration increased the total removal of chemical oxygen demand up to 70% and total removal of phosphorus to 96.4%. The best removal process for Total phosphorus was achieved using Ca(OH)2 as a flocculant due to a precipitation process that forms calcium phosphate Ca(PO4)2. Based on the results a maximum removal rate for chemical oxygen demand of and total phosphorus of 70% and 96.4% respectively could be achieved, which could make future wastewater treatment more effective.