Remediation of Arsenic Contaminated Soil Using Phosphate and Colloidal Gas Aphron Suspensions Produced from Sapindus mukorossi
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 flow and up flow 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 efficiency 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.
KeywordsArsenic Soapnut Sapindus mukorossi Soil remediation Colloidal gas aphrons
The authors acknowledge the funding provided by University of Malaya, Kuala Lumpur (Project UM-QUB6A-2011) for carrying out this research (Brookins 1986).
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