Study In Stabilization Process Of Modification Sludge And Technology Of Sanitary Landfill

As the rate of our country's urban sewage treatment increases annually, the production of the sludge in sewage treatment plants has increased dramatically and sludge disposal has become an acute problem.Common disposal methods as land use, landfill, burning and making building materials have advantages and disadvantages.According to our current economic situation and future trends, in the near future, landfill still will be the main form of the sludge disposal. However, the traditional way of the sludge landfill has many problems such as low intensity so difficult to compact, low permeability so not be drained, and poor sanitation so can't sustainable.To solve these problems, this paper proposes the concept of modified sludge, that is the original sludge is firstly modified to reach the conditions of landfill access, and then landfilled. According to the specific circumstances of Shanghai, this topic,selecting the aged refuse and magnesium material as the modification, and modified sludge as the research object, analyses the process of landfill gas and the stabilization, and puts forward the designing technology program of sludge sanitary landfill and relevant provisions of transport, pretreatment, and esanitary landfill, in view of the characteristics of the modified sludge unlike garbage , and reaches the main conclusions as follows:(1) Sludge can enter sanitary landfill after modified and reach the condition of access.Usually the modified materials include magnesium or aluminum, aged refuse, solid waste incineration slag, residues of compost, garbage, construction waste, fly ash, lime, soil, etc. Combined with the specific circumstances of Shanghai and the LaoGang landfill, currently the most appropriate modification in LaoGang landfill is aged refuse and magnesium materials.(2) Aged refuse and magnesium belong to two different types of modified materials, and has different characteristics,aged refuse can promote the process of anaerobic gas production of landfill, but magnesium modified materials has the opposite effect. Analysis two modified materials from anaerobic gas production,the best choice is aged refuse if you want to collected and use the gas, and it can speed up the landfill into the stage of methane production, in addition,it can increase in the methane content of landfill gas; it is a suitable choice that select magnesium if it is not big and can not collect and use the gas, magnesium can inhibit the production of landfill gas effectively, so become an effective way to reduce emissions of methane.(3) After 120 days of stabilization, all kinds of indexes of primary and modification sludge were changed, the index of primary sludge has a specific peak, and it is say that is in the state of normal degradation, but all indicators of the modification sludge tended to be stable, explain it has strong stability, the degradation rate is slower in the early. According to fitted relationship, it was found that the organic matter of primary and modification sludge may reach to 20%, the possible lowest value for the landfill, after around 3.95 years, 2.27 years, 4.58 years of placement.(4) The design of the sludge sanitary landfill may be paid more attention to the system of landfill gas and leachate drainage, and the features of low permeability, high water content, high liquidity, size of small,need be considered.