Impact of Industrial Effluents on Soil Health and Agriculture - Indian Experience: Part I - Distillery and Paper Mill Effluents

The disposal of industri al eftluents is a problem of increasing importance throughout the world. In Indi a, a huge amount of waste water generated from distillery and paper industri es is discharged on land or into the running water. Di stillery waste water is characterized by low pH, hi gh BOD and COD values and contains a high percentage of organic and inorganic material s. This waste water also contains considerable amounts of elements like N, P, K, Ca and S. The paper mill effluents are characterized by high values of BOD, COD and wide range of pH, depending upon the source of origin. The N, P and K contents are lower as compared to those in distillery waste waters. Impact of use of these effl uents on soi l, plant and waterbodies is discussed . Use of distillery effluents indicates a significant increase in elec trical conductivity (EC), organic carbon, exchangeable Na as well as avail ab le N, P and K in soil s. Similarly, pH, organic carbon, cation-exc hange capacity, avai lable N, P, K and micronut rient contents of soils irrigated with paper fac tory effluents are reported to be increased. Besides, the use of th is waste water increases the exchangeable Na content of soils. Some of the field crops show positive response to post-methanation eftluent applicat ion with irrigation water. Paper mill effluents are found to adversely affec t the seed germination and seedling growth of various crops, whereas, these aspec ts of crops are stimul ated due to the application of these eftl uents after proper dilution. Increase in organic load, depletion of oxygen content and destruction of aquatic li fe in water course are some of the major problems created due to disposal of these effluents in river. Met hods of control and treatment of these effluents are indi cated . Manuria l potential , strategies and constraints o f utilization of these industri al ertluents in agricu lture are mentioned.