Analysis of eutrophication potential of municipal wastewater

One of the main factors of the increased eutrophication level of surface waters is the high anthropogenic loads of biogenic substances discharged into water bodies. Municipal wastewaters, containing large amounts of nitrogen and phosphorus play one of the key roles in the acceleration of eutrophication intensity. The main direction in the prevention of eutrophication caused by wastewater discharge has become the reduction of nutrient loads introduced to wastewater receivers in accordance with strict legal requirements achievable only in advanced technologies. The treated wastewater quality standards are actually developed for total nitrogen and total phosphorus content, disregarding the fact that eutrophication potential of treated wastewater is determined by the content of non-organic nutrient forms directly bioavailable for water vegetation. That is why the currently used energy-consuming and expensive technologies do not always guarantee effective protection against eutrophication and its consequences. The goal of the study was to analyze the most widely used wastewater treatment technologies for enhanced biological nutrients removal in treated wastewater eutrophication potential. For this purpose, an analysis of the operation of 18 wastewater treatment plants based on different technologies in Finland, Canada, Poland, Russia and the United States was realized. The analysis concluded that the eutrophication potential of treated wastewater to a large extent is conditioned by the applied technology. The results of the research concluded that the eutrophication potential can serve an important criterion for decision-making regarding the proper selection of wastewater treatment technologies aimed at eutrophication mitigation.