Achieving sub-10 ppb arsenic levels with iron based biomass-silica gel composites

Concrete stabilization of arsenic-bearing iron sludge generated from an electrochemical arsenic remediation plant

“…Arsenic contamination in groundwater is a widespread global water pollution issue that affects most severely communities in the Bengal Basin of India and Bangladesh in South Asia (Fujita et al, 2009;Gadgil et al, 2012;Roy, 2013, 2015;Das et al, 2016;Nazari et al, 2016). The consumption of groundwater containing toxic levels of arsenic increases the risk for various cancers, including skin, lungs and brain (Yoshida et al, 2004;Clancy et al, 2013;Martínez-Cabanas et al, 2015), as well as cardiovascular, respiratory and immune system diseases (WHO, 1996;Yoshida et al, 2004). Arsenic contamination is estimated to affect over 144 million people around the world (Clancy et al, 2013), with over 70 million individuals in South Asia alone (Dhar et al, 1997;Shrestha et al, 2003;Shafiquzzaman et al, 2010).…”

“…The arsenic crisis in South Asia has prompted the development and installation of several arsenic removal technologies (Patterson, 2006;Das and Roy, 2015;Das et al, 2016;Liang et al, 2017), many of which rely on sorption of arsenic to oxides of iron (Fe), aluminum (Al) or manganese (Mn) (Martínez-Cabanas et al, 2015). Iron-oxide based sorption technologies, particularly those based on electrolysis of Fe(0) such as Electrochemical Arsenic Remediation (ECAR) (van Genuchten et al, 2012;Amrose et al, 2013aAmrose et al, , 2013bDas and Roy, 2015;Das et al, 2016) are more efficient and less costly than other sorption technologies and also require less support infrastructure, which facilitates sustainable operation in remote, decentralized communities.…”

New polymeric/inorganic hybrid sorbents based on red mud and nanosized magnetite for large scale applications in As(V) removal

“…Mixtures were stirred on a rotary shaker (Compact Shaker KS-15, Edmund Bühler GmbH, Hechingen, Germany) at 175 rpm during 3 h (raw materials) or 24 h (hybrid materials) at room temperature. Studies were carried out at natural pH ( 7), except for red mud experiments, where natural pH was very high ( 10), therefore the solution pH was adjusted to 6.5-7 by addition of small volumes of a concentrated HCl solution. Aliquots of the supernatant solution were taken and analysed as mentioned above.…”

“…Iron (hydr)oxides are regarded as promising adsorbent materials as they have strong affinities towards inorganic arsenic species which result in high selectivity to arsenic in the sorption processes; moreover, they are low-cost and environmental friendly. Some examples of the different available materials presenting arsenic sorption are: iron hydroxide-coated alumina, manganese greensand and ferrihydrite [6] as well as iron based biomass-silica gel composites [7] or activated carbon loaded with iron [8].…”

Effective cementation and removal of arsenic with copper powder in a hydrochloric acid system

“…Based on human health data, a concentration of 10 ppm has been recommended by WHO as a guideline value for drinking water. 7,8 Till now, various technologies and approaches have been exploited to remove arsenic, such as ion exchange, 9 precipitation, [10][11][12][13] reverse osmosis, [14][15][16] bioremediation, 17 and adsorption, [18][19][20][21][22][23] electrodeposition, [24][25][26] coagulation, [27][28][29][30] etc. However, they are usually subject to low efficiency, strict operation condition, high cost or expensive materials.…”