Chemically enhanced primary treatment (CEPT) forremoval of carbon and nutrients from municipalwastewater treatment plants: a case study of Shanghai

摘要

With Chemically Enhanced Primary Treatment (CEPT) as the short-term process, the capacityof Bailonggang Wastewater Treatment Plant accounts for almost 25% of the total capacity ofwastewater treatment in Shanghai, China. However, shortly after this plant was placed inoperation in 2004, it was found that the effluent of CEPT couldn't meet the new nationaldischarge criteria. Although the removal of phosphate is almost 80%, chemical oxygen demand(COD) and ammonia nitrogen (NH3-N) in the effluent is frequently found to exceed the standards.The primary goal of this research is to investigate the possibility of optimizing the CEPT to makeit meet the discharge criteria before it is upgraded to a secondary treatment. An oxidant isadopted to remove NH3-N, and a high performance polyaluminum chloride (HP-PACI) issynthesized to enhance the removal of COD. It is found that HP-PACI improves the removal ofCOD, and the oxidant enhances NH3-N removal effectively. However, to meet the requirement ofa newly implemented stricter discharge standard, it is necessary to upgrade this CEPT to asecondary treatment. The results of this study provide scientific evidence for the upgrade of theBailonggang Wastewater Treatment Plant.