Removal of arsenate and arsenite from aqueous solution by waste cast iron.
The removal of As(III) and As(V) from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experiment: grind precipitate dust (GPD) and cast iron shot (CIS). The X-ray diffraction analysis indicated the presence of Feo on GPD and CIS. Batch experiments were performed under different concentrations of As(III) and As(V) and at various initial pH levels. Results showed that waste cast iron was effective in the removal of arsenic. The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result. In the adsorption of both As(IH) and As(V), the adsorption capacity of GPD was greater than CIS, mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS. Results also indicated the removal of As(III) and As(V) by GPD and CIS was influenced by the initial solution pH, generally decreasing with increasing pH from 3.0 to 10.5. In addition, both GPD and CIS were more effective at the removal of As(III) than As(V) under given experimental conditions. This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.
Department of Rural Systems Engineering, Seoul National University, Seoul 151-921, Republic of Korea. nagchoul@empas.com
Nag-Choul
NC
Choi
Song-Bae
SB
Kim
Soon-Oh
SO
Kim
Jae-Won
JW
Lee
Jun-Boum
JB
Park
D000327:Adsorption; D001149:Arsenates / Q000302:isolation & purification*; D018053:Arsenites / Q000302:isolation & purification*; D011232:Chemical Precipitation; D004577:Electron Probe Microanalysis; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D012996:Solutions; D013696:Temperature; D014866:Waste Products / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D014961:X-Ray Diffraction
D001149:Arsenates; D018053:Arsenites; D012996:Solutions; D014866:Waste Products; D014874:Water Pollutants, Chemical; D007501:Iron; C015001:arsenite; C025657:arsenic acid