Author/Authors :
Njoku, P.C. Federal University of Technology - Department of Chemistry, Nigeria , Nweze, C.A. Federal University of Technology - Department of Chemistry, Nigeria
Abstract :
The physiochemical influence of soil minerals (Bentonite, Kaolinite, Diatomite,Rutile and Ferrihydrite) on the organic reduction of chromium (VI) has been investigated with Oxalic acid as the organic reductant. The effect of pH and particle sizes of the soil minerals were also investigated. Results showed that with 0.1mol/dm3 concentration of Oxalicacid, the concentration of chromium(VI) remaining was 0.28, 0.34, 0.38, 0.46 and 0.52mg/kgfor Bentonite, Rutile, Diatomite, Kaolinite and Ferrihydrite respectively whereas at 0.5mol/dm3 of oxalic acid, the concentration of chromium reduced to 0.20, 0.26, 0.30, 0.38, and 0.44mg/kg for Bentonite, Rutile, Diatomite, Kaolinite and Ferrihydrite. Increased concentration of oxalic acid increased the reduction of chromium(VI) to chromium(III). At pH 5.0, the concentration of chromium(VI) left was 0.28, 0.34, 0.38, 0.46 and 0.52mg/kg for Bentonite, Rutile, Diatomite, Kaolinite and Ferrihydrite while at pH 2.5, concentration was 0.16, 0.22, 0.26, 0.34 and 0.43mg/kg respectively. At particle size of 47-42 microns,concentration of chromium(VI) was 0.28, 0.34, 0.38, 0.46, 0.52mg/kg for the same order of the soil minerals. At micron sizes of 33-29 and 28-25 ranges the concentration of chromium(VI) left was 0.23, 0.29, 0.33, 0.41 and 0.47mg/kg for both micron sizes and corresponding minerals as well. These results showed that above 33-29 micron sizes, the influence of particle size was negligible.
NaturalLanguageKeyword :
soil minerals , organic reduction , chromium (VI) , oxalic acid
