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http://crossmark.crossref.org/dialog/?doi=10.1007/s00128-016-1878-4&domain=pdf
Web End = Bull Environ Contam Toxicol (2017) 98:366372 DOI 10.1007/s00128-016-1878-4
http://crossmark.crossref.org/dialog/?doi=10.1007/s00128-016-1878-4&domain=pdf
Web End = Remediation of Arsenic Contaminated Soil Using Phosphate and Colloidal Gas Aphron Suspensions Produced from Sapindus mukorossi
Soumyadeep Mukhopadhyay1 Sumona Mukherjee1 Mohd Ali Hashim1
Bhaskar Sen Gupta2
Received: 22 December 2015 / Accepted: 30 June 2016 / Published online: 13 July 2016 Springer Science+Business Media New York 2016
Abstract Phosphate and colloidal gas aphrons (CGAs) generated from saponin extracted from Sapindus mukorossi fruit, were evaluated for washing low levels of arsenic from an iron rich soil. Phosphate is one of the most commonly dispersed chemicals that increases arsenic mobility in soil due to their structural similarities, making it an important factor in arsenic removal process. Column washing experiments were performed with CGAs in down ow and up ow modes on soil of pH 5 and 6. Soapnut CGAs, when paired with phosphate removed up to 95 % arsenic while soapnut CGAs alone could only remove up to 70 % arsenic. The presence of phosphate improved efciency of soapnut solution by up to 35 %. SEM image of washed soil revealed minor corrosion of soil surface while using phosphate with soapnut. Therefore, the addition of phosphates would have positive impact on soil washing using soapnut saponin.
Keywords Arsenic Soapnut Sapindus mukorossi Soil
remediation Colloidal gas aphrons
USEPA has classied arsenic as a human carcinogen. Soil and water pollution through mining, smelting, coal burning, wood preservation and illegal waste dumping activities releases arsenic in ecosystem (Tokunaga and Hakuta 2002). In a recent study, soil of golf course was found to be
contaminated with arsenic sourced from seaweed fertiliser (ONeill et al. 2014). Usual screening concentration of arsenic in soil usually varies in the range of 1016 mg Kg-1 for industrial soil (DOE Malaysia 2009). Arsenic and other contaminants can be removed from soil through a host of technologies including bioremediation and soil washing with surfactants and other chemicals (Jang et al. 2005; Majumder et al. 2013; Mukhopadhyay et al. 2015a).
CGAs have shown excellent potential as separation agents for contaminant removal from liquid and soil matrices (Hashim et al. 2012). Saponin, a natural surfactant obtained from the fruit pericarp of Sapindus mukorossi or soapnut has been used for removing organic and inorganic...