Seasonal And Temporal Changes In Heavy Metal Pollution In Sewage And Their Impacts On Soil Quality

摘要

Temporal and seasonal changes in chemical properties of sewage and its impact on soil qualities were studied in the sewage farm of Coimbatore district in western agro-climatic zone of Tamil Nadu. Sewage effluent and soil samples were collected at monthly intervals from five points of the sewage channels in the farm at half a kilometer interval and analyzed for their chemical characteristics. The data have clearly indicated that cationic and anionic composition of sewage effluents get altered appreciably by seasonal variations namely summer, winter or in rainy seasons. Most of the ionic concentrations in the sewage effluent was significantly higher in warmer months during summer than cooler months in winter indicating an intense microbial activity and concentration effect. In contrast, micronutrients content in sewage effluents was increased during rainy months suggesting that anaerobic reduction of solid sludge wastes which would have increased their concentration. Soil properties varied accordingly to the nature and quantities of effluents that used for irrigation leached out of the sewage channels.