Study On Environmental Impact Of Municipal Sewage Sludge In The Sand Improvement

This study use the sand of houtian in jiangxi province as the research object, collecting sludge of qingshanhu sewage treatment plant and nursery base soil in jiangxi agricultural university as the experimental material, leaching sand content of different sludge without wood soil, leaching sand content of different sludge with wood soil through the leaching simulation experiment indoor, then analyzing the effect of activated sludge for sandy soil nutrient content and the status of the groundwater pollution with different dispose, evaluating the comprehensive pollution index of soil sample which sludge been applied,then studying which means can make the best to improve the quality of the desert.Main conclusions are as follows:1. Sludge in qingshanhu sewage treatment plant is weak acid, the organic matter, total nitrogen, total phosphorus and total potassium of sludge were higher than pig and cow dung, it has the good value use to land. Zinc is the highest levels of heavy metals in sludge of qingshanhu sewage treatment plant,it reach 1115.12 mg/kg, followed by Cu is 539.69 mg/kg.Zinc, Pb, Cd and Cr were below the related standards of sludge in our country, the Cu which is only 7.9%, and Cu is the element that plants need, Sludge in qingshanhu sewage treatment plant can be completely applied to the soil improvement.2.The cod and ammonia nitrogen in the leaching liquid are less than a of integrated wastewater discharge standard limit by applying 0.3 g/cm3 sludge with the conditions of doping and doping of woodland soil, reducing the over standard rate of cod and increasing the over standard rate of ammonia nitrogen with woodland soil soil. The conteng of heavy metals in the leaching liquid is much lower than standard limits in three different content sludge,with the condition of doping and doping of woodland soil, the over standard rate of heavy metals increase, but the increase was small.3. The greater sludge content is applying, the total nitrogen retention rate is smaller, The concentration of total phosphorus by applying 1.5g/cm2 sludge was biggest,but it changing when leaching sand content 0.9g/cm2 sludge with wood soil. The leaching risk of total nitrogen is greater than the total phosphorus.4. The concentrations of heavy metals do not exceed the iii standard of Soil environmental quality standards at the biggest risk of pollution, no matter adding wood or not. The greater sludge content is applying, the soil nemerow index is greater.The biggest single pollution index is zinc, Pb is the smallest single pollution index.5. After doping woodland soil, sand has obvious effect of intercepting total phosphorus, the concentration of total phosphorus were decreased corresponding in the liquid.6. Because of mood soil, pH of the blank leaching liquid go down almost a unit, after doping woodland soil, pH of leaching liquid have declined than the original, but the decline is not obvious.7. The nemerow index of soil increase with wood soil under the condition of applying different sludge content, when The nemerow index of soil increased from 0.01 to 0.04 applying sludge content is 0.3g/cm2, The nemerow index of soil increased from 0.05 to 0.07 applying sludge content is 0.9g/cm2, The nemerow index of soil increased from 0.08 to 0.11 applying sludge content is 1.5g/cm2.