Case Study Regarding the Variation of the Qualitative Parameters of Wastewater

Abstract

Romania is making efforts in order to enforce the Directive concerning urban waste water treatment and was left behind by other member states. Starting from the premise that the lack of a proper treatment of wastewater can negatively influence the quality of the emissary in which they are discharged., we proposed that in this paper we analyze the main indicators of wastewater quality, identifying also the causes of water pollution. For this purpose, we followed the variation of five representative indicators of wastewater from Călărași Wastewater Treatment Plan: chemical oxygen consumption, biochemical oxygen consumption, total nitrogen, total phosphorus, suspended solids. The best results in purification were observed regarding the biochemical oxygen consumption (over 95%). The low temperature of wastewater at the entrance to the Wastewater Treatment Plant during winter leads to a difficult exploitation of the biological step and implicitly to the increase of the phosphorus and total nitrogen concentration in the effluent, which means a weak process of eutrophication in the emissary.