Research For The Influence Of Sewage Sludge On The Plant Soil And Water

With the rapid development of industrialization and the quickly growth of urban population,the conflict between increase sludge and environmental carrying capacity is growing intensified. Sludge of consumer satisfaction must be required. The studies on the treatment technical of sludge are in demand. As China is short of natural resources, it is more urgent to research the use of sludge resources.The sludge is full of nutrients like nitrogen, phosphorus, potassium, i.e. As a consequence, the recycle use of sludge is the ideal treatment to it. However, it is restricted by pathogenic microbes, surplus nutrient and heavy metals that contained in the sludge. Now, more and more researchers start to engage in the methods for solving this problem.This subject designed two sets of simulated experimental system, the potted experiment and soil column experiment. This study aims to provide references for the utilization of sludge through finding the appropriate volume of raw sludge and composting sludge.Through its effect on plants,water and soil weighing the pros and cons of sewage sludge.Pot experiment showed that there exists dose relationship between shoot ratio, biomass and sludge fertilizer. With the increasing of application of sludge,the biomass and ratio of root of tall fescue is increased.But when the sludge application rate is very high, ratio of root and biomass of tall fescue is lower than the moderate application rate. This shows that too much sludge has some adverse effects on plant growth and development. Therefore, land use should be strictly controlled in the dosage.The simulated column experiment demonstrated that, the TN and TP were increased significantly with the using of sludge, but the pH value became lower than befor. Moreover,the TN increased apparently with the addition of raw sludge application rate.while phosphorus has little effect on the production cost of agriculture but has great impact on eutrophication of surface water and groundwater.Therefore,whether the raw sludge amount or the composting sludge amount were should be controled in a certain range.The paper studied of heavy metals in leachate.The experiment shouwed that the element of Mn is most likely to cause potential pollution of groundwater in raw sludge series. But in composting series the most harmful element is As.This study analyzed the soil nutrients and heavy metals in the migration and transformation, as well as the inflence of plants and water. And finally found the pest fertilizer for the raw sludge and the composting sludge, respectively were 10% and 15%.