Heavy Metals Stability Experimental Study On The Sewage Sludge Of Urban Sewage Treatment Plant

The final disposition of city sewage sludge is a difficult problem and a challenge which both domestic and abroad have to face. Domestic technology of dealing with sewage sludge is too simple. Moreover, the organics content of sewage sludge which has been discharged is very high. They are easy to get corrupt, have malodor, and they also contain parasitic ovum, pathogenic microorganism, heavy metal and many compounds. So, we can see that the composition of pollution is very complicated, especially for the dealing with heavy metal, which is very difficult to get the standard of sanitary landfill. Heavy metal usually contains the acute or chronic toxicity that can contaminate human body in many ways. For instance, they can result in cancer or indirectly result in some disease. which has brought out a series of serious consequence, like environment pollution, etc. So, dispose of sewage sludge problem has become an urgent task.During the process of disposing the waste of heavy metal, mostly, stabilizing treatment is needed to reach the purpose of innocent treatment. There are many categories of conventional technology of heavy metal stabilizing treatment, but there is also some limits when these categories are used on the deposition for heavy metal. Especially, these technologies can be influenced by pH value. When pH valve is low, heavy metal ions will be stripping again, then, the purpose of long–term stabilizing treatment of heavy metal would not be obtained. During the final waste disposal, environment will suffer the secondary pollution. Be aimed a these problems, using a high performance chemistry stabilizing medicament to deposit the innocent treatment has been put forward, which also become a studying hot spot of innocent treatment of depositing the dangerous waste. This paper mainly studies on the qualitative and quantitative analysis of sewage sludge, and the heavy metal desactivation of sewage sludge. The experiment of thesis will choose the sludge that is from XiAn sewage plant as a studying objective, Allowable maximal pollution contents , foul water factory infusion liquid heavy metal in the farm-oriented sludge suitable for use reaching conclusion Xi An City foul water sludge cadmium Cd , mercury Hg , lead Pb , copper Cu , zinc Zn , nickel Ni all quantity regulation without exception exceeding《pollution controls a standard in farm-oriented sludge》(GB4248-84) , lead Pb exceed《dangerous good-for-nothing distinguishes a standard leaching out toxicity being distinguished》(GB5085.3-2007) regulation maximal allow contents. Conclusion of experiment: using heavy metal sequester to deposit is more across-the-aboard, holding a comparative high rate of wiping for each index,Heavy metal chelating agent nature of the polymer analysis,Heavy metal chelating agent that the mechanism of heavy metal passivation , to EP-110 connect to heavy metal ions with covalent bond, a spatial structure of the polymer stability chelates;(EP-110)Pharmacy deal with all kinds of metal ions,The Range of pH is 3.0～11.0. After processing the metal ion content lower than the emission standards; The optimum dosage of conclusions,EP-110/Heavy Metal Content(W/W): EP-110/Cu²⁺(6.5～7.5:1),EP-110/Ni²⁺(7.0～8.0:1),EP-110/Pb²⁺(1.5～2.5:1),EP-110/Zn²⁺(8.5～9.5:1),EP-110/Cd²⁺(3.5～4.5:1),Hg2(+2.0～2.5:1);the amount of throwing the dose is few, so that the cost of deposition can be reduced more. and use compound heavy metal sequester to deposit the heavy metal that exists in the sludge, which already get an obvious effect. It comes up to the every standard of sanitary landfill of Chinese decree.