Effects Of Sludge Utilization On Plant Growth And Environmental Influences

In recent years, with the rapid development of economic and the quickly growth of urban population in China, the massive growth in the amount of sludge has become more and more attention, the relative scarcity of our natural resources, and it becomes our pressing problems that how to use the sludge resourcely. Rich content of organic matter and nitrogen, phosphorus and other elements in the sludge, and how to improve the utilization of the sludge has been a hot research topic, but the substance is in the sludge will cause secondary pollution to the environment, we restrict the use of sludge Utilization of the determinants of the sludge, many Chinese and foreign scholars to explore and study on this issue.This project mixed lime-drying sludge and thermal drying sludge with the soil, potted plants and soil column, maked this two experimental systems to test, from the balance of positive and negative effectiveness, and find the landscaping, planting agricultural lime-drying sludge mud and thermal drying sludge application rate, and provide a reference for the land use of sludge.(1)The pot experiment showed that:the number of significant correlation between plant biomass and sludge application rate. Within a certain range, sludge application, the more the greater the biomass of radish; but beyond this, the sludge application more radish biomass are smaller. This indicates that the sludge use in land too will plant growth and development to bring some negative impact in the landscape, agriculture planting should be strictly controlled doses.(2)The soil column leaching Simulation results show that: total phosphorus and total nitrogen in the sludge mixed soil leaching solution a significant increase in pH decreased. Thermal drying sludge series after the leaching treatment, the leaching solution of a higher nitrogen content, easy to cause pollution of groundwater. phosphorus content in the leaching solution on the eutrophication of water bodies have a greater impact, in order to avoid nitrogen and phosphorus cause eutrophication of surface water and groundwater and other water bodies, whether it is a sludge of lime-drying or thermal drying sludge application are must be controlled within a certain range.(3)Through single-factor pollution assessment method, the research shows that: in lime-drying sludge series, As is the key factor for potential contamination of water, and in thermal drying sludge series, Mn is the key factor for potential contamination of water. Both of them may cause water potential pollution. Through multi-factor pollution assessment method, the research shows that: in lime-drying sludge series, the pollution levels of heavy metals is0.6244, and in thermal drying sludge series, the pollution levels of heavy metals is0.7608. Pollution levels are low, Both of them is unlikely to pollute water.This topic potted radish test and soil column leaching simulations, the study analyzed the migration of lime-drying sludge mixed soil and thermal drying sludge mixed soil of nutrients and heavy metals, as well as plants and water impact, and then find the best application rate of lime-drying sludge and thermal drying sludge in the soil for30%and20%, respectively.