Combined effects of water pH and alkalinity on the accumulation of lead, cadmium and chromium to labeo rohita [hamilton]

ABSTRACT

Influence of pH [5.5, 7.0 and 8.5] and alkalinity [40 to 200 mg/L as CaCO3] on the accumulation of Pb [NO3]2, CdCl2, H2O and K2Cr2O7 to Labeo rohita [Hamilton] was investigated in the laboratory. Highest accumulation of Pb and Cr in whole fish occurred at pH 5.5 and at alkalinity level of 40 to 46 mg/L as CaCO3 compared to 7.0 and 8.5. In case of Cd maximum accumulation occurred at pH 7.0 and at alkalinity of 100 mg/L as CaCO3 than that of pH 5.5 and 8.5 and alkalinity 42 and 156 mg/L as CaCO3. Maximum accumulation of lead and chromium occurred at total alkalinity level of 40 and 46 mg/L as CaCO3, respectively while maximum accumulation of cadmium occurred at an alkalinity level of 200 mg/L as CaCO3. A significant [p<0.05] linear relationship was demonstrated between increasing pH/ alkalinity and decreasing accumulation in Pb and Cr treatment at all exposure period while for Cd there was no significant linear relationship established