Investigation of effect of different filtration rate and iron-manganase concentration on filter efficiency

In this study, a laboratory-scale slow sand filter was used to remove iron and manganese from ground waters. The effects of different filtration rates and different iron-manganese concentrations on the filtration efficiency were investigated. The laboratory-scale slow sand filter with 40x60x50 cm dimensions composed of two filter units in parallel. Headloss through the filters was measured by several manometers at various depths of the filter units. In addition, microbial species analysis was carried out to determine the active species and samples were taken at different depths in each operating conditions. Operating conditions in experimental study includes: SSF1: 1 mg/L Fe-Mn at 0.1 m/h, SSF2: 2 mg/L Fe-Mn at 0.1 m/h, SSF3: 1 mg/L Fe-Mn at 0.2 m/h, SSF4: 2 mg/L Fe-Mn at 0.2 m/h, SSF5: 1 mg/L Fe-Mn at 0.3 m/h, SSF6: 2 mg/L Fe-Mn at 0.3 m/h. Average turbidity removal efficiencies in SSF1, SSF2, SSF3, SSF4, SSF5, and SSF6 were 94.8±2.8%, 95.9±2.6%, 96.3±2.4%, 97.9±1.3%, 97.7±0.8% and 98.2±0.8%, respectively. On the other hand, iron removal efficiencies were 90.4±4.8%, 94.4±3.2%, 92.3±6.1%, 93.1±8.1%, 93.4±4.4% and 95.4±4.8%, while manganese removal efficiencies were 90.3±5.8%, 95.4±5.2%, 92.7±5.7%, 94.3±5.7%, 94.9±6.1% and 95.9±3.5%, respectively. Average total organic carbon removal efficiencies in SSF1, SSF2, SSF3, SSF4, SSF5, and SSF6 were 52.3±3.6%, 49.3±5.8%, 55.3±8.3%, 55.5±6.8%, 52.0±4.8% and 57.6±8.2%, respectively. Effective microbial species for each operating condition in the study; Gallionella sp., Leptothrix sp., Crenothrix sp. and Hypochondrium sp. was found.