EFFECTS OF VARYING INLET IRON AND MANGANESE CONCENTRATIONS ON SLOW SAND FILTER PERFORMANCE

Abstract

In this study a laboratory-scale slow sand filter (SSF) is used for removal of iron and manganese and the effects of various inlet concentrations on removal efficiency were investigated. SSF was operated at a filtration rate of 0.2 m.h(-1) with two different synthetic inlet waters (Run1 and Run2). Iron and manganese concentrations in two runs were 1.09 +/- 0.13mg. L-1-1.06 +/- 0.10 mg.L-1 for Run1 and 2.02 +/- 0.15 mg.L-1-2.10 +/- 0.14 mg.L-1 for Run2. In Run1, the removal efficiencies of 96.3 +/- 2.48%, 92.3 +/- 6.1%, 92.6 +/- 5.7%, and 55.3 +/- 8.3% were obtained for turbidity, iron, manganese and total organic carbon (TOC), respectively. In Run2, on the other hand, the removal efficiencies were obtained as 97.9 +/- 1.3%, 93.1 +/- 8.1%, 94.4 +/- 5.8%, and 55.5 +/- 6.8%, respectively. Results suggested that the SSF was the most efficient in turbidity removal at a filtration rate of 0.2 m.h(-1). Sequence analyses of DGGE bands from Run1 and Run2 were also performed and results indicated that a range of bacteria were present, with 16S rRNA gene sequences similar to groups such as Gallionella, Leptothrix, Crenothrix, and an uncharacterized environmental clone.