Efficiency of Horizontal Roughing Filter in Removing Suspended Solids from Effluent of Waste Stabilization Ponds in 2013

Background & Aims of the Study: The Horizontal roughing filters (HRF) are generally formed with three layers. The size of the course at the beginning of the flow path is large and at the end is small. This kind of layering increases absorption capacity while the solids entering the bed&ndash;depth gradually separate because of the decline in the holes&rsquo; diameters. This study aimed to examine the efficiency of HRFs in removing total suspended solids (TSS) from effluent of a waste stabilization pond. Materials & Methods: This experimental study was conducted in 2013. The pilot project was transferred to the Karaj wastewater treatment plant (waste stabilization pond), Alborz province of Iran. Then, the installation, equipping and start-up of the system began, using an effluent treatment plant. Sampling was done from March to August in 3 rates of 0.5, 1 and 1.5 m/h, which was included simultaneous sampling from inlet and outlet HRF to determine the concentrations of TSS. Results: The results showed that at filtration rates of 0.5, 1, and 1.5 m/h, the average of TSS removal was equaled to 42.46, 56.65 and 33.22%, respectively. The removal efficiency of TSS at the rate of 1m/h was more than 0.5 and 1.5 m/h rate (p<0.05). The Outlet value of TSS was lower than the standards which are set by the Environmental Standards Organization (ESO) (P < 0.05). Conclusion: According to the results of this study, the HRF function was approximately adequate in TSS removal and can be a suitable option for improving the quality of stabilization ponds effluent.