An experiment was conducted to assess the growth performance of four canola varieties with effluents of three different tanneries i.e. Raji, Haji Boota and Dildar Khan of District Kasur. Shoot length, Shoot fresh and dry weight, root fresh and dry weight, chlorophyll a and b, no of seeds per plant, no of pods per plant seed weight and no of seeds per pod were investigated. The results showed that all parameters under all three effluents treatments showed reduced growth performance and also yield of the plants reduced greatly. Maximum growth reduction were found in plants treated with effluents with Haji Boota. It is also showed from the analysis of seeds that, chromium was found in the seeds which is thought to be taken up from effluent.
The determination of total chromium in different streams of tannery effluents were carried out by the digestion of samples in a HNO3:H2SO4 mixture followed by KMnO4 oxidation, which resulted in the complete conversion of Cr(III) to Cr(VI). The Cr(VI) (Cr2O72-) species present in these samples were estimated by UV–visible spectrophotometry (1,5-diphenyl carbazide method). The results obtained were critically evaluated. UV–visible spectrophotometry was found to be better suited for this analysis.