Abstract
The reduction rates of Cr(V) by some organic compounds were investigated in order to obtain an information on the reactivity of Cr(VI) and organic matter in natural water. Glycine, serine, tyrosine and aspartic acid reduced hardly any Cr(VI) in the solution of pH 2, while cysteine, tannic acid and lignin rapidly reduced it even at pH 4. The reduction rates of Cr(VI) by cysteine and tannic acid were precisely determined as a function of concentration of reactants, pH and temperature. The emprical rate equations are -d[Cr(VI)]/dt=kcySH·103.3×1011[H +]2[CySH][Cr(VI)] for cysteine and =kTan[H +] [Tannic acid (mg/l)]1/2[Cr(VI)] for tannic acid. The apparent rate constants, kcySH, and kTan were found to be 4.8 and 1.4 x103min-1 at 20°C, respectively. Cr(VI) in fresh water may be reduced at a considerable rate b rganic matter such as tannic acid and some of the humic substances.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
