TREATMENT OF ORGANIC WASTE WATER BY TRICKLING FILTER

Abstract

Trickling filters are basically a fixed-film biological reactor; where organic matter _01- are absorbed and oxidized by attach microbial film. The performance of trickling filter designed more recently is comparable to that of activated sludge plants. The advantage of trickling filter is that it provides good performance and less energy requiremeri. In the present study the effect of variableA•such as hydraulic flow rate, organic loading, recirculation ratio and depth on the performance of high rate trickling filter have been studied. The influent COD, recycle ratio, influent flow rate and bed depth significantly influence the performance of the trickling filter. Experiment have been carried out with laboratory scale trickling filter of size 7.5 cm in diameter and 175 cm (150 cm effective depth) in depth packed with gravel inert solids packing mediahaving a size range of 5 mm too 25 mm. Influent COD varied from 250 mg/I to 1000 mg/I, removal efficiency was founddecrease with increase of influent COD. Because of nonavailibilty of industrial wastewater of uniform characteristics for these experiments, synthetic waste prepared by dissolving a known amount of molasses in the tap water, was used. The saturation constant Km is experimentally determined as 1121.8 mg/1 at flow rate of 0.012 m3/hr. The study is useful for the design of trickling filters for the removal of carbonaceous BOD from industrial wastewaters.