EFFECT OF SEWAGE SLUDGE ON THE CONTAMINATION OF SOIL WITH HEAVY METALS
The recovery of sewage sludge is an urgent environmental problem in Russia. The utilization of sewage sludge in agriculture is an important recovery method, but it is little used in Russia. The long-term application of urban waste water to the soil has increased the contents of heavy metals, including cadmium, which often exceeds the maximum permissible concentration. The high levels of heavy metals prevent the use of sewage sludge as a fertilizer. It has been suggested to improve the formula for calculating the application rates of sewage sludge to the soil.