| 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 | 
       
      |