Characteristics And Composting Of Rural Living Garbage In Different Rural Areas Of Chongqing

With the development of rural economy, rural living garbage increased gradually and its components become complexed. Lack of the technology of treatment has become an important factor. We must pay attention. Municipal sludge is the byproducts during sewage treatment. It has been reported that rural living garbage can be composting with sludge. However, the rates of sludge added from different researchers are different due to the difference in the components of garbage.Therefore, the characteristics and treatment methods of the rural living garbages from four different villages including Lianghe, Yanba, Yuanyang and Wuxin villages in Chongqing were investigated. On thoses basis, the influence of sewage sludge additionon on rural living garbrge compostingprocess was also investigated.The main results were listed as follows:1. The rural living garbage generation rates were 0.226±0.168,0.286±0.203, 0.217±0.124and0.282±0.123 kg per capita per day, respectively, with the villages of Yanba and Wuxin being the highest, and Yuanyang village being the least. Of the components in the garbage, organic materials has the highest percentage, which was 45.0%～55.0%, followed by wrapping paper and plastic, other component content was lowest.2.Except the Yuanyang village, the treatments for garbages were al follows: Farmers who live closely to garbage collection room use the mode of "village collection-town transfer-county processing" to treatthsirliving garbage, the others mixed their garbage together and thrown them away.3. Temperature in all treatments reached 50℃ on the first day of composting, and met the hygiene requirements for the composting harmless standards. Addition of different rates of sludge to the compost piles can increase the pH, bulk density and decrease the EC values, however, the EC values for all compost piles were greater than 4.0mS-cm-1. Total organic carbon decreased with composting time, addition of sludge increased total organic carbon and the more the sludge addition, the lower the total organic carbon content. Total nitrogen and total phosphotus increased with sludge addition. Addition of 20% of sludge is beneficial to improve the quality of compost products.4. Fulvic and humiccontents in the process decreased, but the contents of heavy metals and available metals increased with the addition of sludge. The affinity of Cu and Zn to HA was weaker than those of Pb and Cd. It was concluded that the humification process of organic matter was not the mainly way to reduce the available Cu and Zn during composting. Because the content of HA-Cd was much higher than the availianle Cd and FA-Cd, it can be effective to decrease the content of availianle Cd and Pb by increasing the HI.5. The changes of GI values can be divided into three stages, inhibited germination phase (0.293～0.303); rised phase (0.743～0.832); declined phase (0.515～0.620), all met the basic requirement of non-toxic. And there was little effect on the GI values with sludge addition.