Birjand is a city in the east of Iran. Underground water is the only drinking water source, because this city is in a dry region.Ground water hexavalent chromium ion (Cr +6 ) concentration in Birjand is about 0.07 mg/l, which is higher than the maximum contamination level (MCL). The maximum contamination level of Cr +6 is 0.05 mg/l according to WHO guidelines.In an effort to comply with the World Health Organization (WHO) guideline regulations governing hexavalent chromium, Cr +6 was reduced to Cr 3 through standard jar test procedures with the addition of ferrous sulphate as a reducing agent. This research studied this as a bench scale.In the first alternative, ferrous sulphate was just used as a reducing agent. A chromium concentration of 0.042 mg/l was reached in order to comply with WHO guidelines. But the addition of ferrous sulphate induced a sulphate ion (SO 4 2-) concentration increment of up to 430 mg/l, which is higher than the maximum contamination level according WHO guidelines (400 mg/l).In the second alternative, ferrous sulphate was used as a reducing agent with lime milk.A chromium concentration of 0.015 mg/l was reached with a sulphate ion concentration of 380 mg/l, which is less than the MCL (400 mg/l).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.