UMASHANKER SAIN* AND NARSI R. BISHNOI**
Department of Environmental Science & Engineering, Guru Jambheshwar University of Science & Technology, Hisar-125 001 (Haryana), India
*(e-mail : firstname.lastname@example.org; ** email@example.com)
(Received : February 12, 2018; Accepted : April 20, 2018)
Traditional tertiary treatment method involved sand filter, activated charcoal filtration as an advanced treatment method for removal of total solid, turbidity, colour, bio-nutrients from wastewater either domestic or trade effluent. These present techniques slowly decreased removal efficiency of impurities or pollutants due to their low filtration rate and inadequate specific gravity gradation. Therefore, multigrade multimedia filtration is a modified filtration technique consisting of mainly sand, anthracite and garnet as filter media. Different sizes and grades of gravel were used as supporting media in this study. Variable specific gravities were the key components that enhanced the filtration rate of filter media which was selected for designing of multigrade multimedia filtration column. Acrylic and polycarbonate pipe was used to design the multimedia column with multi-layered media of natural (sand, garnet, anthracite), synthetic (recycled glass media) and industrial waste (crushed ceramic bushes) products. Column consisted of a 150 mm diameter and 2.0 m in height containing total 600 mm depth of multi-layered media. The multigrade multimedia filtration column was designed by applying different Hydraulic Loading Rates (HLR) ranging from 3.0-7.0 m/day and the media used were of an effective size from 0.3 to 3.0 mm. 4.5 m/ day was the optimized HLR that showed maximum removal of suspended solid from secondary treated wastewater by multigrade multimedia column.
Key words : Multigrade multimedia filtration, filter media, TSS, removal efficiency, hydraulic loading rates