عنوان مقاله [English]
User-friendly and low-cost wastewater treatment plants are good options for treating wastewater of small communities. The effluent of these treatment plants can be improved by various methods including using a horizontal rouphing filter (HRF). In this paper, HRF performance was evaluat by passing the Parkandabad wastewater treatment plant effluent through pilot scale constructed HRF. The HRF was constudted with four- compartments of different sand sizes and was operated under three filtration rates of 0.5, 1 and 1.5 m3/m2.h. The results obtained from this study showed that the HFR performed the best at filtration rate of 0.5m/h when the removal efficiency for BOD5 and COD was 61 and 63 %, respectively. Optimum removal efficieny of BOD5 and COD up to 65% could be achieved with an extended filtration run length. However, longer duration of filter operation after 4 months, reduced the filter performance for BOD5 and COD removal efficiency to 56.8 and 61.5%, respectivel. In conclusion, by using 4-compartment HRFs, compared with the conventional 3-compartment filtration, it may be possible to produce effluent quality for BOD5 and COD that is permissible for agricultural irrigation purposes.