A proposal for sequential approach for arsenic removal from top-soil
Arsenic contamination of ground water and soil is a vexing problem in several countries, including India. For water treatment there have been several effective, economical and commercially available [methods] (http://www.hindawi.com/journals/tswj/2014/304524/#B161). [Phytoremidiation] (http://www.hindawi.com/journals/ijce/2011/939161/), [microbial remediation] (http://link.springer.com/article/10.1007%2Fs00253-013-4838-5), [genetically modified plants with bacterial genes and hybrid approach of both bacteria and plant accumulating Arsenic] (http://www.sciencedirect.com/science/article/pii/S098194280201375X) have been used for Arsenic removal from soil, with some success in field studies. We propose a novel hybrid approach of removing iron from soil, which interferes with freely available arsenic, followed by further mobilization of arsenic by increasing soil acidification along with absorption by suitable plants and fungi, followed by removal of arsenic from the biomass. We propose removal of iron by fertilizing soil with iron accumulating bacteria. Following the initial treatment, we would then add detritus to decrease soil pH, along with arsenic accumulating non-edible plants and fungi that produce easily harvestable biomass but cannot be utilized directly by humans. The next step would be solubilization of harvested biomass in a fermenter, which can also be used to produce natural gas. The solubilized slurry can then be treated with several successful approaches for [slurry] (http://www.neptjournal.com/journal-details.php?id=49&q_id=7) and [water treatment] (http://www.hindawi.com/journals/tswj/2014/304524/#B161). We have not proposed combining microbial bioaccumulation and using chemical methods due to cost and feasibility issues. Our sequential approach presents a possibly effective and practical approach of soil arsenic remediation.
Attachment: Arsenic_removal_proposal_figure.pdf (21.2 KB)