[{"id":206,"title":"A proposal for sequential approach for arsenic removal from top-soil","sha":"839221c4a79ee72d68db5c4209371835","user_id":null,"state":"published","body":"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\u0026q_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. \r\n","created_at":"2015-08-19T10:53:58.761Z","updated_at":"2015-09-03T17:54:31.683Z","zenodo_id":57553,"doi":"http://dx.doi.org/10.5281/zenodo.29583","subject":null,"tags":["arsenic","poisoning","contamination","soil pollution","bioremidiation","phytoremidiation","microbial remidiation","iron removing bacteria","detritus"],"vote_count":1,"view_count":1,"score":1.1,"deleted":false,"muted":false,"tweeted":false,"attachment_file_name":"Arsenic_removal_proposal_figure.pdf","attachment_content_type":"application/pdf","attachment_file_size":21673,"attachment_updated_at":"2015-08-19T10:56:51.839Z"},{"id":203,"title":" Magnification of arsenic poisoning factors along the length of river","sha":"21f71f41a776e5a4b3cafa6da6476c8d","user_id":null,"state":"published","body":"Previous studies have not explored the link between the downstream distance of rivers and increased incidence of arsenic toxicity. We find that in South Asia almost all the sites of arsenic toxicity are close to a river and are furthest from the source of river. The 3 factors that we posit are contributing to this distribution but have not been studied are: 1. deforestation, 2. misguided commercial forestation and 3. runoff and magnification in rivers. Deforestation and misguided commercial forestation of plants that results in reduced biodiversity and soil holding capacity contribute to erosion and leaching of arsenic. Massive commercial forestation in Northern Himalayas and expansion of agriculture in North Indian plains in the last few centuries have drastically altered the previous equilibrium of the system. Runoff in river can influence increased arsenic toxicity in 3 ways: 1. direct runoff of pesticides and other compounds containing arsenic, 2. industrial, agricultural and domestic-use compounds that increase arsenic mobilization and 3. decreased pH that increases arsenic mobilization. In the coming years, we expect additional factors of ground water cycling and other anthropogenic factors to alter this distribution and worsen the situation of arsenic toxicity. \r\n\r\n","created_at":"2015-08-16T11:17:23.393Z","updated_at":"2015-09-03T18:04:26.997Z","zenodo_id":54096,"doi":"http://dx.doi.org/10.5281/zenodo.28094","subject":null,"tags":["arsenic","poisoning","toxicity","river","deforestation","biomagnification","runoff","pesticide","ph","anthropogenic","south asia"],"vote_count":3,"view_count":1,"score":3.1,"deleted":false,"muted":false,"tweeted":true,"attachment_file_name":null,"attachment_content_type":null,"attachment_file_size":null,"attachment_updated_at":null}]