Assessment of Leather Tannery Effluent Using Multiple Indicators

In the present study physico chemical parameters such as Temperature, pH, Total dissolved solids, Total suspended solids, Electrical Conductivity, Calcium, Magnesium, Total Hardness, Chloride, Sulphate, Phosphate, Nitrate, Nitrite, Biological Oxygen Demand, Chemical Oxygen Demand and Dissolved oxygen were analyzed in the leather tannery of Dindigul, Tamil Nadu. All the parameters were found to be above the standard limit. The tannery effluent was alkaline with high BOD and COD, along with higher concentration of Total dissolved solids and Total Suspended solids, Sodium adsorption ratio and high amount of sodium having water quality class C3S1. A systematic statistical analysis showed correlation between water quality parameters. Water quality index minimum (WQI minimum) calculated using Temperature, pH, Electrical conductivity, DO and Total suspended solids which showed that effluent belonged to bad water class. Water quality index (WQI) calculated using all the 16 physico-chemical parameters showed that effluent belonged to very bad water class. The total dissolved solid present in the effluent is maximum hence effluent is unfit for irrigation and for any use. The discharge of leather tannery effluent is leading to the contamination of ground water to the surrounding area and highly polluting the environment. It can thus be concluded that waste effluent from leather tannery is unfit for agricultural use and it may have deleterious effect on soils when used for irrigation purposes causing salinity and sodicity problems unless proper management techniques are adopted.