Lab-scale experimental investigation concerning ex-situ bioremediation of mercury (Hg) contaminated soil by local bacterial isolated from Bombana mining area

Abstract

Hg Contamination is a most common occurrence in the industrial area, caused by several industrial activity wich release Hg into environment, like industrial activity of gold mining in Bombana Regency Southeast Sulawesi, Indonesia. So that it need effort to controll Hg contamination, one of wich is bioremediation techniques using bacterial. The aims of this study were to know the effect of local bacterial and incubation time to reduce the Hg content at post-gold mining soil of Bombana Regency. This study was experimental research atlab-scale (ex-situ bioremediation) using Completely Random Design (RAL) with two factorial. The 1st factor was the kind of bacterial inoculum namely Pseudomonassp. strain LIIC (Ps), Bacillussp.strain LIIIC (Bc), and mixed inoculum both of these bacterial species (PB). The 2nd factor was incubation time consist of 1st week until 8th weeks incubation. Soil substrate contaminated by Hg was inoculated of bacteria inoculum as much as 100 mL/kg and incubated at room temperature for 8 weeks. Hg content was measured by AAS (Atomic Absorption Spectrophotometer).Data was analysed by software SAS. The result of inoculated of local bacteria and incubation times affect to the Hg content on post-gold mining soil. The highest reduction of Hg content at the treatment of Pseudomonas sp. LIIC inoculated was 98,89% with the optimum incubation time in the second weeks.