id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-346715-r6a5vxl0	Liu, Haizhou	Hexavalent chromium in drinking water: Chemistry, challenges and future outlook on Sn(II)- and photocatalyst-based treatment	2020-08-10		.txt	text/plain	4576	234	43	Chromium (Cr) typically exists in either trivalent and hexavalent oxidation states in drinking water, i.e., Cr(III) and Cr(VI), with Cr(VI) of particular concern in recent years due to its high toxicity and new regulatory standards. To moving forward in the right direction, three key questions need further exploration for the technology implementation, including effective management of residual waste, minimizing the risks of Cr(VI) re-occurrence downstream of drinking water treatment plant, and promote the socioeconomic drivers for Cr(VI) control in the future. The reactions of Cr(III) solids oxidation by free chlorine residuals can take place in drinking water distribution systems, as supported by statistical analysis of EPA UCMR3 database. Redox-driven Cr(VI) treatment technologies are more promising and cost-effective than physical separation technologies (for example, ion exchange), because Cr (VI) is chemically reduced to non-toxic Cr(III) solids in the presence of a reductant and subsequently removed as Cr (III) particles, eliminating the need for additional brine disposal (Eary and Rai, 1988) .	./cache/cord-346715-r6a5vxl0.txt	./txt/cord-346715-r6a5vxl0.txt