Bioclogging in porous media: influence in reduction of hydraulic conductivity and organic contaminants during synthetic leachate permeation.

Subramaniam Kanmani,Kasinathan Muthukkumaran,Rajan Gandhimathi

doi:10.1186/s40201-014-0126-2

Abstract

In this study the concept of biofilm accumulation in the sand column was promoted to assess the changes in hydraulic conductivity and concentration of organic contaminants of the synthetic leachate. Four different combinations of column study were carried out using synthetic leachate as a substrate solution. Mixed and stratified mode of experiments with two different sizes (0.3 mm and 0.6 mm) of sand grains were used for column filling. Two columns were acting as a blank, the remaining two columns amended with mixed microbial cultures which were isolated from leachate. The column was operated with continuous synthetic leachate supply for 45 days. The results indicated that the highest hydraulic conductivity reduction occurred in the mixed sand microbial column with 98.8% when compared to stratified sand microbial column. The analysis of organic contaminants of the effluent leachate was also clearly shown that the mixed sand amended with microbes poses a suitable remedial measure when compared to natural and synthetic liners for controlling the leachate migration in the subsurface environment.

Highlights

The generation of solid waste has become an increasing environmental and public health problem everywhere in the universe, especially in the developing countries [1]
Chemical Oxygen Demand (COD) of the synthetic leachate was measured at 14000 mg/L using the closed reflux method. 40 ml of isolated mixed bacterial culture was transplanted to 400 ml of synthetic leachate solution contains 14,000 mg/L of COD [52]
Four different sets of experiments were conducted for assessing changes in hydraulic conductivity permeated with a synthetic leachate solution

Summary

Introduction

The generation of solid waste has become an increasing environmental and public health problem everywhere in the universe, especially in the developing countries [1]. The biofilm accumulation in the porous media is an effective way in the reduction of hydraulic conductivity and concentration of organic contaminants from the leachate. Several authors reported a significant reduction of hydraulic conductivity due to bioclogging These studies demonstrated that the biobarrier may be a promising technology for containing contaminant plume in the field. The influence of biofilm accumulation using sand column is described by (1) the reduction in hydraulic conductivity of the inoculated microbial sand column (2) the physico-chemical characteristic of the effluent leachate such as pH, turbidity, total dissolved solids (TDS), oxidation reduction potential (ORP), nitrates, phosphates and degradation of organic contaminants in terms of COD

Materials and methods

Results and discussion

Conclusion

35. Donlan MR: Biofilms

50. IS 2720

76. Armstrong MD