TY - JOUR
T1 - Arsenic removal from drinking water through a hybrid ion exchange membrane - Coagulation process
AU - Oehmen, Adrian
AU - Valerio, Rita
AU - Llanos, Javier
AU - Fradinho, Joana
AU - Serra, Susana
AU - Reis, Maria A. M.
AU - Crespo, João G.
AU - Velizarov, Svetlozar
N1 - The financial support by Fundacao para a Ciencia e a Tecnologia (FCT), Lisbon, Portugal through projects PEst-C/EQB/LA0006/2011, PPCDT/AMB/57356/2004 and PTDC/AMB/65702/2006 is gratefully acknowledged.
PY - 2011/11/15
Y1 - 2011/11/15
N2 - A hybrid process targeting arsenic (As) removal from drinking water was developed in this study, consisting of arsenate transport through an anion exchange membrane followed by coagulation. The main advantage of this ion exchange membrane (IEM) process is improved drinking water quality through the prevention of secondary contamination by coagulants and pH-controlling agents, a design feature that was successfully confirmed experimentally. This study describes: (1) the selection of an appropriate anion exchange membrane for transporting monovalent and divalent forms of arsenate, (2) the effects of iron (Fe) vs. aluminium (Al) coagulants on the process, (3) the long-term efficacy of the IEM process and (4) a comparison of the IEM process effectiveness with conventional coagulation/filtration. Al was found to be more effective than Fe at preventing membrane scaling, likely due to the contrasting charges of the precipitates, which are repelled from the positively charged membrane in the case of Al, unlike Fe. Arsenate was removed below the maximum contaminant level (6.6 ± 2.8 ppb) during periods with and without Al addition, where minimal operational maintenance was required. The high quality drinking water that is achievable and its ease of operation make the IEM process attractive for treating As-containing water supplies.
AB - A hybrid process targeting arsenic (As) removal from drinking water was developed in this study, consisting of arsenate transport through an anion exchange membrane followed by coagulation. The main advantage of this ion exchange membrane (IEM) process is improved drinking water quality through the prevention of secondary contamination by coagulants and pH-controlling agents, a design feature that was successfully confirmed experimentally. This study describes: (1) the selection of an appropriate anion exchange membrane for transporting monovalent and divalent forms of arsenate, (2) the effects of iron (Fe) vs. aluminium (Al) coagulants on the process, (3) the long-term efficacy of the IEM process and (4) a comparison of the IEM process effectiveness with conventional coagulation/filtration. Al was found to be more effective than Fe at preventing membrane scaling, likely due to the contrasting charges of the precipitates, which are repelled from the positively charged membrane in the case of Al, unlike Fe. Arsenate was removed below the maximum contaminant level (6.6 ± 2.8 ppb) during periods with and without Al addition, where minimal operational maintenance was required. The high quality drinking water that is achievable and its ease of operation make the IEM process attractive for treating As-containing water supplies.
KW - Arsenic
KW - Chemical precipitation
KW - Donnan dialysis
KW - Groundwater
KW - Heavy metals
UR - http://www.scopus.com/inward/record.url?scp=80055085671&partnerID=8YFLogxK
U2 - 10.1016/j.seppur.2011.09.027
DO - 10.1016/j.seppur.2011.09.027
M3 - Article
AN - SCOPUS:80055085671
SN - 1383-5866
VL - 83
SP - 137
EP - 143
JO - Separation and Purification Technology
JF - Separation and Purification Technology
IS - 1
ER -
