IEG 환경지질연구정보센터

10월 26일(금)․지구화학

2007 추계지질과학연합학술대회 초록집

Geochemical evaluation on the use of scoria and steel slag for simultaneous removal of multiple contaminants in water

Jang-Soon Kwon^* · Jonghwa Lee · Seong-Taek Yun · Ho Young Jo Department of Earth & Environmental Sciences, Korea University, [email protected]

We conducted kinetic and equilibrium sorption experiments on removal of divalent heavy metals (Pb(II), Cu(II), Zn(II), Cd(II)) and trivalent arsenic (As(III)) from aqueous solutions by scoria (a vesicular pyroclastic rock with basaltic composition) from Jeju Island and steel slag (basic oxygen furnace slag: BOFS; an agglomerate generating during a steel manufactur- ing process) from the Pohang Iron & Steel Works, Korea, in order to its potential use as an efficient sorbent. The batch-type kinetic sorption tests indicated the removal efficiencies of heavy metals and arsenic except lead ion (Pb(II)) by steel slag are slight higher than that by scoria. However, the hydration of slag composition during the tests provides a high pH (> 11) in the aqueous solutions. Careful examination of ionic concentrations in sorption batch- es suggests that for heavy metals the sorption behaviors onto scoria and steel slag are mainly controlled by cation exchange and precipitation with metal hydroxides, respectively, and for arsenic that are sensitive by physical adsorption onto hematite (minor constituent of scoria) and calcium-arsenite precipitation, respectively. Equilibrium sorption tests show that the re- moval capacity of heavy metals onto scoria increases with increasing pH of sorbates, likely due to hydroxide precipitation.Multi-component system with heavy metals and arsenic also show the arsenic removal efficiency increases with increasing metal hydroxide precipitates by the coprecipitation. The acquired kinetic sorption data are better fitted to the pseudo-sec- ond-order model than first-order model (Lagergren equation), and the equilibrium sorption data of heavy metals and arsenic onto scoria are well explained by the langmuir isotherm and the Freundlich isotherm, respectively.

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