TY - JOUR
T1 - A novel sequential process for remediating rare-earth wastewater
AU - Cui, Mingcan
AU - Jang, Min
AU - Kang, Kyounglim
AU - Kim, Dukmin
AU - Snyder, Shane A.
AU - Khim, Jeehyeong
N1 - Funding Information:
This work was supported by the Korean Institute of Energy Technology Evaluation and Planning (KETEP) Project (KETEP, No. Q1512121) and by the Malaysian Government Ministry of Higher Education through the High Impact Research Grant ( D000062-16001 ).
PY - 2016/2/1
Y1 - 2016/2/1
N2 - A novel and economic sequential process consisting of precipitation, adsorption, and oxidation was developed to remediate actual rare-earth (RE) wastewater containing various toxic pollutants, including radioactive species. In the precipitation step, porous air stones (PAS) containing waste oyster shell (WOS), PASWOS, was prepared and used to precipitate most heavy metals with >97% removal efficiencies. The SEM-EDS analysis revealed that PAS plays a key role in preventing the surface coating of precipitants on the surface of WOS and in releasing the dissolved species of WOS successively. For the adsorption step, a polyurethane (PU) impregnated by coal mine drainage sludge (CMDS), PUCMDS, was synthesized and applied to deplete fluoride (F), arsenic (As), uranium (U), and thorium (Th) that remained after precipitation. The continuous-mode sequential process using PASWOS, PUCMDS, and ozone (O3) had 99.9-100% removal efficiencies of heavy metals, 99.3-99.9% of F and As, 95.8-99.4% of U and Th, and 92.4% of CODCr for 100 days. The sequential process can treat RE wastewater economically and effectively without stirred-tank reactors, pH controller, continuous injection of chemicals, and significant sludge generation, as well as the quality of the outlet met the EPA recommended limits.
AB - A novel and economic sequential process consisting of precipitation, adsorption, and oxidation was developed to remediate actual rare-earth (RE) wastewater containing various toxic pollutants, including radioactive species. In the precipitation step, porous air stones (PAS) containing waste oyster shell (WOS), PASWOS, was prepared and used to precipitate most heavy metals with >97% removal efficiencies. The SEM-EDS analysis revealed that PAS plays a key role in preventing the surface coating of precipitants on the surface of WOS and in releasing the dissolved species of WOS successively. For the adsorption step, a polyurethane (PU) impregnated by coal mine drainage sludge (CMDS), PUCMDS, was synthesized and applied to deplete fluoride (F), arsenic (As), uranium (U), and thorium (Th) that remained after precipitation. The continuous-mode sequential process using PASWOS, PUCMDS, and ozone (O3) had 99.9-100% removal efficiencies of heavy metals, 99.3-99.9% of F and As, 95.8-99.4% of U and Th, and 92.4% of CODCr for 100 days. The sequential process can treat RE wastewater economically and effectively without stirred-tank reactors, pH controller, continuous injection of chemicals, and significant sludge generation, as well as the quality of the outlet met the EPA recommended limits.
KW - Adsorption
KW - Oxidation
KW - Precipitation
KW - Rare-earth
KW - Wastewater
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U2 - 10.1016/j.chemosphere.2015.10.107
DO - 10.1016/j.chemosphere.2015.10.107
M3 - Article
C2 - 26583290
AN - SCOPUS:84953775096
SN - 0045-6535
VL - 144
SP - 2081
EP - 2090
JO - Chemosphere
JF - Chemosphere
ER -