Pollution Research Paper

ASSESSING THE MOBILITY OF SALTS IN SOIL DUE TO THE APPLICATION OF TANNERY SLUDGE COMPOST

N. JEYAPANDIYAN, P. DORAISAMY AND M. MAHESWARI

Abstract

Tannery industries create serious environmental problems especially in terms of organic effluent and the hazardous solid wastes as a result of hides and skin processing. Leather tanning industries contribute to most of the chromium contamination, through the disposal of wastewater directly to the streams and by the disposal of sludge or solid waste to the land. In addition to essential nutrients, sludge also contains elements such as Cr, Zn, Pb, Cu, Ni and Cd. Hence, the disposal sites must be carefully managed to eliminate percolation water and ensure control of trace element which may be hazardous to plants and human health. A laboratory study was conducted to assess the mobility of salts due to the application of tannery sludge compost on soil. The treatment was fixed based on the Nitrogen requirement of maize crop which was used as test crop in field condition. Column study indicated that different levels of tannery sludge compost application influence on pH, EC, NO3-N, Na and Chromium in soil. Leaching of NO3-N was higher in the treatment that received 12.5 ton ha-1 of tannery sludge compost and maximum chromium was also recorded in this treatment. It was within the limit. Leachates contained lower amount of salts showing that the application of tannery sludge compost may not contaminate the soil and groundwater.