Abstract:The purpose of this research is to investigate a biofilm system with trickling filter as a biological alternative process during low cost treatment connection with the possibility of reducing nutrients such as phosphorus. Given that nitrogen with phosphorus that are leading causes of algal bloom resulting in increased eutrophication or chemical nutrients are the basis of this document analysis. This increase in organisms results in less oxygen in water bodies and at times, slow decay leads many fresh water ponds, lakes and rivers. The process of eutrophication unfortunately tends to favor pollution and algae, which reduce the quality of the water. Kosovo has not a long tradition in the treatment of wastewater, especially in removing phosphorus, since the country has only a plant for wastewater treatment. The present plant is intended to protect the Klina river from eutrophication from wastewater discharged after treatment. This plant currently reduced phosphorus efficiently, but the goal of this paper is to increase the percentage of removal of phosphorus to 40% through trickling filters, presenting options for optimizing work on plant Skenderaj.