One of the most vital problems of environmental protection concern is that of solid waste disposal. This problem continues to grow with the growth of population and the development of industries. The Common Effluent Treatment Plant (CETP) already establishes itself as a service to society at large, contributing towards a cleaner environment. However, the inappropriate disposal of CETP?s hazardous sludge can cause serious environmental problems. The sludge if sent for landfilling may cause groundwater contamination, changing the soil fertility parameters as well. The research presented here is carried out to explore the ability of an epigeic earthworm Eudrilus eugeniae to transform the sludge produced from CETP into a value-added product i.e., vermicompost. In this study, six samples of feed mixture were used with different ratios of CETP sludge, cow dung, and sawdust. Physico-chemical parameters such as pH, Electrical Conductivity (EC), Volatile Solids (VS), Total Nitrogen (TN), Nitrate Nitrogen (NO3--N), Ammonium Nitrogen (NH4+-N) were characterized to analyze the quality of the compost formed. All these parameters are in the agreement with recommended standards of mature compost. The result shows that vermicomposting technique when used, epigeic earthworm Eudrilus eugeniae can work as a favorable alternative solution for the disposal of CETP sludge.

Total 150 sediments samples were collected from the Yangzong Lake, and the total phosphorus, pH, redox potential and organic carbon were analysed to quantitatively study the dispersal and sources of phosphorus and its influential factors. The results indicated that the total phosphorus content in sediments was 318-3931 mg/kg, which decreased slightly with depth. In the sediments at the depths of 0-2cm, 2-4cm, 4-6cm, 6-8cm and 8-10cm, the phosphorus contents were 1151mg/kg, 1126mg/kg, 1138mg/kg, 1057mg/kg and 893mg/kg respectively. The contents of phosphorus in the sediments were high on both north and south banks and reduced gradually towards the centre of the lake. Before the 1980s, the phosphorus distribution in the sediments was mainly influenced by natural factors such as pH value, redox potential and organic matter. But after the 1980s, the phosphorus distribution was mainly affected by the position of sewage discharge. Sources of phosphorus in the sediments have changed from the local source to the multiple sources, and from the point source to surface source. Currently, soil erosion and agricultural non-point source pollution are the main sources of phosphorus in Yangzong Lake.