Pollutants Removal Efficiency in the Hydroponic Lagoon of the Wastewater Treatment Plant

Abstract Wastewater treatment in semi-natural systems, such as a hydroponic lagoon operating as the third stage of treatment, is becoming more and more popular because of the efficiency of organic matter and nutrient removal. The article presents an analysis of the efficiency of pollutant removal at the mechanical-biological wastewater treatment plant in Gronów with a capacity of Qd = 1125m3/day and a load of 9375 PE. The wastewater treatment plant operates on the basis of activated sludge and biomass settling technology on submerged flow beds. The treatment plant is characterized by a very high variability of wastewater inflow during the year due to periodic inflow of wastewater from tourist resorts in Łagów. The average efficiency of removing pollutants from wastewater was: BOD5 - 98.5%, COD - 92.8%, total suspended solids - 93.2%, total nitrogen - 86.1% and total phosphorus - 69.5%. The study showed that the use of a hydroponic lagoon in the technological system improved the efficiency of wastewater treatment by 1.7% for BOD5, 0.9% - COD, total suspended solids by 4.3%, 6.4% for total nitrogen and total phosphorus- 3.3%.