Feasibility study on bioclogging by bacterial fermentation using bioaugmentation and biostimulation methods

Abstract

Bioclogging can be induced by in situ accumulation of biopolymer produced by bacteria in soils. The bioclogging can be achieved either by bioaugmentation or biostimulation strategies. A preliminary study was conducted to examine the feasibility of bioaugmentation and biostimulation methods to induce fermentation-base bioclogging effect in sands. In experiments, the model bacterium, Leuconostoc mesenteroides, and a consortium of indigenous soil bacteria from an embankment were examined for bioaugmentation and biostimulation, respectively, where in situ production of bacterial biopolymer through microbial fermentation was stimulated while monitoring reduction in hydraulic conductivity of sands for more than 40 days. The results revealed that both strategies can reduce the hydraulic conductivity of sands by 1−2 orders of magnitude. It was concluded that a biostimulation method using sucroserich growth media was applicable to induce fermentation-base bioclogging in the embankment site that the soil bacteria were sampled.