nutrient elimination from effluent of municipal wastewater treatment plant applying horizontal roughing filter

high levels of turbidity and suspended solids are the major disadvantages of aerated lagoons. aerated lagoon effluent filtration was investigated by horizontal roughing filter (hrf). removal efficiencies were determined by examining total phosphorus (tp) and total kjeldahl nitrogen (tkn) from hrf influent and effluent, simultaneously. hrf pilot system located on effluent pump station of qom wastewater treatment plant and was put into operation at the filtration rate of 1 m3/m2.h. the main objective was to evaluate the performance of horizontal roughing filter for nutrient removal from aerated lagoon effluent. the filter was fed with continuously aerated lagoon effluent during a 62 days filtration run period. tkn and tp removal efficiencies were 46.6% and 53.8%, respectively. the average inlet and outlet tkn during filtration were 14.49 ±1.63 and 7.73 ±2.84 mg nh3/l, respectively. moreover, tp was measured 5.7 ±0.83 and 2.63 ±0.63 mg p/l for filter inlet and outlet, respectively. it was shown that horizontal roughing filter has a significant effect on total kjeldahl nitrogen (p