Parameters studied Concentration 0th day 5th day 10th day 15th day 20th day 25th day Control   Sample pH 7.3 7.3 7.6 7.9 8.0 8.3 8.7 Calcium mg/l 108 108 94.3 89.4 70.1 62.3 59.7 Magnesium mg/l 78 78 74 65 57 49.2 38 Sulphate mg/l 256 256 213 185.2 156 132.1 76 COD mg/l 459.3 459.3 414.7 343 301.2 278.2 154.1 BOD mg/l 104 104 94.1 79 64 39.4 14.7 Nickel mg/l 8.4 8.4 7.3 6.3 5.4 3.2 2 Zinc mg/l 12.1 12.1 10.1 8.1 7.4 5.3 3.2 Decolourization 1.83 1.83 - - - - 0.63

Table 5: Variability in physico-chemical properties of textile industry effluent during phycoremediation by Oscillotoria salina.