Arsenic Bioremediation by Indigenous Heavy Metal Resistant Bacteria of Fly Ash Pond

Abstract

Fly ash (FA), the major by-product of coal-fired thermal power plants, causes significant environmental degradation owing to its injurious heavy metal contents. Leaching of arsenic (As) from ash ponds is especially significant as As released from FA can increase As concentration of drinking water above maximum contaminant level of 10 ppb. The aim of this paper was demonstration of As bioremediation potential of indigenous As resistant bacteria present in the weathered pond ash sample. Ten isolates belonging to Bacillus, Micrococcus, Kytococcus and Staphylococcus genera were characterized. Biochemical tests showed reduction of relatively non toxic arsenate to more toxic arsenite by two strains while four strains showed oxidation of arsenite to arsenate. Two exoplolysaccharide producing strains were shown to absorb As within their biomass. Total heterotrophs versus As resistant heterotrophs counting performed showed that FA was enriched with As resistant heterotrophs. Column leaching based microcosm study revealed overall As detoxification potential of the isolated microbes.

Water and soil contaminated by arsenic: the use of microorganisms and plants in bioremediation

“…AS-1, Delftia spp. BAs29, Ensifer adhaerens , Micrococcus sp., Pseudomonas chengduensis , and T. arsenivorans (Biswas and Sarkar 2019 ; Biswas et al 2019 ; Corsini et al 2014 ; Ito et al 2012 ; Jebelli et al 2018 ; Lu et al 2018 ; Roychowdhury et al 2018 ; Wan et al 2010 ).…”

Ecological restoration of fly‐ash disposal areas: Challenges and opportunities

“…along with toxic elements such as selenium (Se), arsenic (As), vanadium (V), boron (B), aluminium (Al), mercury (Hg), chromium (Cr), lead (Pb), cadmium (Cd), and so forth. These can cause metal(loid)s toxicity in plants (Sushil andBatra 2006, Koukouzas et al 2011;Roychowdhury et al 2018;Gaji c et al, 2016;Gaji c, Djurdjevi c, et al, 2020). The presence of essential elements in FA can be utilised for the growth of plants but if these exceed permissible limits, it results in metal(loid) toxicity (Pandey et al, 2009;Singh et al, 2010).…”

Bacteria in Heavy Metal Remediation and Nanoparticle Biosynthesis

“…Consequently, two exopolysaccharide-producing strains were revealed to soak up arsenic within their biomass. Arsenic-resistant heterotrophs versus total heterotrophs counting demonstrated that fly ash was augmented with arsenic-resilient heterotrophs . Chromium is considered to be noxious due to its association with additional metals.…”

“…Arsenicresistant heterotrophs versus total heterotrophs counting demonstrated that fly ash was augmented with arsenic-resilient heterotrophs. 82 Chromium is considered to be noxious due to its association with additional metals. In one study, among the isolates from 300 bacteria, strains, namely, Pseudomonas f luorescens and Bacillus safensis, were reported to have the capacity to degrade chromium more than 84% and 72%, respectively; phylogenetic association of 16S rRNA was unwavering by applying bioinformatics, and YKS2 and YPS3 bacterial species were detected with 100% resemblance of sequences.…”