Parameters studied Concentration
0th day 5th day 10th day 15th day 20th day 25th day
Control   Sample
pH 7.3 7.3 8.2 8.5 8.9 9.4 9.6
Calcium mg/l 108 108 99.2 96.3 92.2 87 89
Magnesium mg/l 78 78 74.3 69.4 64.2 61 56.4
Sulphate mg/l 256 256 242 212 187 156.1 114
COD mg/l 459.3 459.3 304 281 242.6 201 184.7
BOD mg/l 104 104 90 78 55.3 31 17.4
Nickel mg/l 8.4 8.4 7.4 6.3 5.2 4.1 3.1
Zinc mg/l 12.1 12.1 10.2 9.1 8.3 7.1 5.2
Decolourization 1.83 1.83 - - - - 0.25
Table 3: Variability in physico-chemical properties of textile industry effluent during phycoremediation by Anabaena variabilis.