Volume No. 3 Issue No.: 2 Page No.: 400-406 Oct-Dec 2008

 

REMOVAL OF NICKEL AND CADMIUM IONS FROM AQUEOUS WASTE WATER BY NANO FILTRATION

 

Latesh B. Chaudhari1 and Z.V.P. Murthy*2

1. Department of Chemical Engineering, N.G. Patel Polytechnic, Bardoli, Gujarat, (INDIA)
2. Department of Chemical Engineering, S.V.N.I.T., Surat (INDIA)

 

Received on : July 13, 2008

 

ABSTRACT

 

Nanofiltration is used for the treatment of wastewater containing heavy metals to reduce fresh water consumption and prevent the environmental degradation. In the present study, removal of Ni2+ and Cd2+ ions from synthetic aqueous wastewater has been investigated by a commercial nanofiltration membrane Perma-TFC-NF-300. Experiments with binary aqueous solutions (CdCl2-NiCl2-water) and (CdSO4-NiSO4-water) are performed to know the influence of the anion on the separation of nickel and cadmium ions. The experiments are carried out for different feed concentrations (5, 50 and 150 ppm), feed flowrates (5, 10 and 15 L/min) and feed pressures (4, 8, 12, 16 and 20 atm), and corresponding permeate flux and rejection/separation are measured. The rejection of both Ni2+ and Cd2+ ions increase with increase in pressure. Rejection increases with higher valency of the anion owing to increased electrostatic repulsion by the membrane. The rejection increases as the feed flowrate increases at constant feed pressure. The rejection of Ni2+ and Cd2+ ions decrease with increase in feed concentration. Maximum rejection of Ni2+ and Cd2+ ions observed are 98% and 97% for CdSO4-NiSO4-water and 85% and 80% for CdCl2-NiCl2-water systems, respectively.

 

Keywords : Flux, Heavy metal, Nanofiltration, Permeate, Rejection

 

 

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