Treatment of some wastes for their utilization in cultivation and environmental protection

The important findings could be summarized as follows: • Improving sewage sludge by using drying beds, chemically by addition of 5% lime and biologically by composting with plant residue caused reduction in the soluble heavy metals contents and killing all pathogens (Fecal, strepto coliform) and Salmonella and Shigella. •Application of different composting materials to the soil increased the EC values. The highest EC value (6.8 dSm. 1) was observed in case of 4% lime compost followed by 4% cotton compost(3.5 dSm. 1) The highest pH value was also obtained in case of lime compost followed by cotton compost, corn compost, rice compost and sewage sludge compost, but all pH values were lesser than the control (8.81).The application of composting materials also increased the values of macro, micro-nutrients (N, P, K, Mn, Zn and Cu) and heavy metals (Pb, Cd and Ni) in soil after cultivation compared with control. The highest increase in trace elements was obtained with the soil treated by sewage sludge followed by the soil treated by plant residues. In wheat grains, the macro and micro elements content were influenced by different composted materials. The increase in NPK content in wheat grains could be arranged as following sequence: sewage sludge treatment lime compost plant residues compost. Similar results were obtained with wheat straw. Physiological parameters (total carbohydrate and protein in grains, and total chlorophyll in leaves) of wheat plant with all treatments were increased according to the following sequence: soil treated with sewage sludge soil treated with lime compost different compost materials (rice straw, corn stalks and cotton stalks). Values of plant were significantly increased in response to sewage sludge treatments compared with control. The highest growth parameters and yield components of wheat plants were obtained with 4% sewage sludge compost.