INQUISAL   20936
INSTITUTO DE QUIMICA DE SAN LUIS "DR. ROBERTO ANTONIO OLSINA"
Unidad Ejecutora - UE
artículos
Título:
Experimental investigation on arsenic removal with a nanofiltration pilot plant from naturally contaminated groundwater
Autor/es:
SAITUA, HUGO; GIL, RAÚL; PEREZ PADILLA, ANTONIO
Revista:
DESALINATION
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2011 vol. 274 p. 1 - 6
ISSN:
0011-9164
Resumen:
In this research, the efciency and the arsenic removal mechanism with a Nano sizefiltration (NF) pilot plant from naturally contaminated groundwater have been evaluated. The process integral evaluation at 7 bar shows an arsenate (HAsO4²−) rejection over 95% and a total sulfate (SO4²−) rejection. Divalent ions calcium and magnesium (Ca²+ and Mg²+) rejection produced an 81% reduction of the total hardness. The total dissolved solids TDS concentration decreased to 53%. Monovalent ions moderated rejections contributed to the membrane hydraulics stability. The arsenate (HAsO4²−) rejection from an electrolytes solution (SO4 2−, HCO3 −, F−, Cl−, NO3 −, Ca2+, Mg2+, K+ and Na+) was prevalently ruled by Donnan exclusion combined with the preferential passage of more permeable ions. Results show the importance of ionic composition on ion transmission and rejection in the studied membrane. Ion rejection in multicomponent solutions showed to be significantly different to that in individual salt solutions. Whereas monovalent anion rejections remarkably decreased, divalent cation rejections were three times superior. In arsenate rejection (HAsO4²−) from artificially contaminated natural groundwater, the membrane showed the same selectivity.ficiency and the arsenic removal mechanism with a Nanofiltration (NF) pilot plant from naturally contaminated groundwater have been evaluated. The process integral evaluation at 7 bar shows an arsenate (HAsO4²−) rejection over 95% and a total sulfate (SO4²−) rejection. Divalent ions calcium and magnesium (Ca²+ and Mg²+) rejection produced an 81% reduction of the total hardness. The total dissolved solids TDS concentration decreased to 53%. Monovalent ions moderated rejections contributed to the membrane hydraulics stability. The arsenate (HAsO4²−) rejection from an electrolytes solution (SO4 2−, HCO3 −, F−, Cl−, NO3 −, Ca2+, Mg2+, K+ and Na+) was prevalently ruled by Donnan exclusion combined with the preferential passage of more permeable ions. Results show the importance of ionic composition on ion transmission and rejection in the studied membrane. Ion rejection in multicomponent solutions showed to be significantly different to that in individual salt solutions. Whereas monovalent anion rejections remarkably decreased, divalent cation rejections were three times superior. In arsenate rejection (HAsO4²−) from artificially contaminated natural groundwater, the membrane showed the same selectivity.