Zrównoważone gospodarowanie ściekami na przykładzie obszarów wiejskich

The Baltic Sea is highly susceptible to eutrophication. Among the nine countries located in the Baltic Sea catchment area Poland discharges the biggest load of nitrogen and phosphorus. Although in recent years this load has been significantly reduced, however it is still too high. No sustainable municipal management results in the decreasing water quality of the Baltic Sea contributing to the sea eutrophication. The implementation of the National Programme for Development of Sewage caused a number of activities related to the construction and modernization of existing wastewater treatment plants. Although the number of wastewater treatment plants has been constantly increasing, still a number of households do not have the possibility to connect to the municipal wastewater treatment plant, mainly for economic reasons. Although in Poland there is 3157 municipal wastewater treatment plants (the most in Central and Eastern Europe), only 64% of the population is connected to them. It is estimated that 7.64 million people do not have the possibility of connection to municipal wastewater treatment plants. One of the solutions to wastewater management, especially in non-urbanized areas, are on-site wastewater treatment plants, for example treatment wetland systems. These technologies provide a sustainable solution of sewage and sludge management, since they can be used not only for treatment of wastewater, but also for dewatering and stabilization of produced sewage sludge. The article presents the results of research on local constructed wetlands for biological wastewater treatment (from 15 to 750 inhabitants) located in Darżlubie, Wieszyno, Wiklino, Sarbsk and Schodno as well as individual treatment wetlands representing 9 on-site wastewater treatment plants built in three different configurations in the municipality of Stężyca. There are also results of research from sludge treatment reed beds used for dewatering and stabilization of sewage sludge from municipal wastewater treatment plants located in Denmark (Helsinge, Rudkobing, Nakskov, Vallo) and in Poland (Gniewino). Based on studies related to the latest examples of wastewater and sewage sludge management using treatment wetlands it has been shown that this method is a good example of ecological engineering. Local treatment wetland systems can be used as the second stage of wastewater treatment up to 3500 residents. With proper operation of primary tanks, these systems are characterized by high treatment efficiency. Treatment wetland systems can work as on-site wastewater treatment plants. The highest efficiency of pollutant removal was observed in the hybrid systems. Another facilities, constructed as reed beds or basins, are applied to effective dewatering and stabilization of sewage sludge. These facilities offer a sustainable solution of sludge management in local conditions.