title: Removal of hexavalent Cr by coconut coir and derived chars--the effect of surface functionality.
abstract: The Cr(VI) removal by coconut coir (CC) and chars obtained at various pyrolysis temperatures were evaluated. Increasing the pyrolysis temperature resulted in an increased surface area of the chars, while the corresponding content of oxygen-containing functional groups of the chars decreased. The Cr(VI) removal by CC and CC-derived chars was primarily attributed to the reduction of Cr(VI) to Cr(III) by the materials and the extent and rate of the Cr(VI) reduction were determined by the oxygen-containing functional groups in the materials. The contribution of pure Cr(VI) adsorption to the overall Cr(VI) removal became relatively significant for the chars obtained at higher temperatures. Accordingly, to develop a cost-effective method for removing Cr(VI) from water, the original CC is more advantageous than the carbonaceous counterparts because no pyrolysis is required for the application and CC has a higher content of functional groups for reducing Cr(VI) to less toxic Cr(III).
authors: Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 40227, Taiwan, ROC.
authors: Ying-Shuian
authors: YS
authors: Shen
authors: Shan-Li
authors: SL
authors: Wang
authors: Yu-Min
authors: YM
authors: Tzou
authors: Ya-Yi
authors: YY
authors: Yan
authors: Wen-Hui
authors: WH
authors: Kuan
mesh_terms: D000042:Absorption; D002857:Chromium / Q000737:chemistry / Q000302:isolation & purification*; D003059:Cocos / Q000737:chemistry*; D005374:Filtration / Q000379:methods*; D008031:Lignin / Q000031:analogs & derivatives* / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D010936:Plant Extracts; D014874:Water Pollutants, Chemical; C507903:coir; D014867:Water; D002857:Chromium; C074702:chromium hexavalent ion; D008031:Lignin