Research On Comparation Of Pollution Characteristics And Recycling Process Risk Assessment Of Heavy Metals In Municipal Solid Waste Incineration Fly Ash About Typical Countries And Regions

The rapid growth of municipal solid waste has become one of the most difficultenvironmental problems, and Domestic waste incineration treatment as the mainmeans of garbage harmless reduction and energy conversion has become a dominantway of garbage disposal in European Denmark, Sweden and and Asia Taiwan andJapan. Similarly, it can be expected in the next few years that garbage incinerationwill become the main technology development direction in super-large city of China.Waste incineration fly ash is the waste incineration technology popularization andrapid development with the hazardous waste. Waste source reduction and wholeprocess management mode of MSW fly ash and achievements will significantlyinfluence the physical and chemical characteristics.Based on the analysis the pollution characteristics of MSW fly ash about typicalcountries and regions and the treatment of MSW fly ash disposal and resourcerecovery utilization process, workers at room temperature and high temperatureenvironment for a long time, the typical heavy metal pollutants exposed to oral intake,skin contact or fly ash leaching of heavy metals in groundwater pollution constitutes arisk to human health through the food chain of different scenarios, this researchattempts to build the fly ash disposal process of risk assessment models and methods,and application of risk assessment software fly ash disposal process for differentsituations of environmental risk has carried on the preliminary assessment.The institute to obtain the results:1. comparative analysis pollution characteristics of heavy metals in fly ash ofChinese mainland, Taiwan and Japan.(1) The concentration distribution of heavy metals in the inland areas of China,Taiwan and Japan in the fly ash and comparison. Analysis found that the content ofheavy metals Cd, Cr, Ni are very low, and Zn, Cu and Pb are generally high in the flyash.In inland areas of China and Japan the average concentration of six heavy metals in the fly ash, follow the low of Zn> Pb> Cu> Cr> Ni> Cd, slightly different law forZn> Pb> Cu> Cr> Cd> Ni in Taiwan. By average concentrations of contrast, theaverage concentration of six heavy metals in the fly ash of Japan were lower than theinland areas of China and Taiwan. While the average concentration of Zn, Cu, Pb aresmall in fly ash of the inland areas of China and Taiwan, which slightly higher inTaiwan than the inland areas. The remaining three heavy metals in fly ash, the averageconcentration of Cd and Ni of Taiwan is higher than the inland areas. Three regions ofheavy metals in fly ash correlation analysis found that waste management is loose andwaste separation is not clear enough in China’s inland, and in Taiwan and Japan wastemanagement is relatively strict and waste separation is better treatment.(2) The TCLP leaching of heavy metals in the inland areas of China, Taiwan andJapan in the fly ash and comparison. In fly ash the leaching value of Zn, Cu and Pb ishigher, and Cd, Cr, Ni leaching value is relatively low, and most of the data is higherthan the EPA leaching standards. By comparison, the TCLP leaching averageconcentration of Zn, Cu, Cd in the fly ash of Chinese mainland were higher than inother areas. In addition to Pb and Cr leaching concentration higher than the inlandareas of China in Japan in the fly ash, the rest TCLP leaching of heavy metalsconcentration were lower than the inland areas of China and Taiwan. the TCLPleaching average concentration of Ni in the fly ash of Taiwanwere higher than that ofJapan and Chinese mainland.(3) The formation distribution of heavy metals in fly ash of Chinese mainland,Taiwan and Japan is studied in this paper. Through principal component analysis, itwas found that two elements Ni and Cr were higher in F4and two elements Cd and Pbwere higher in F1in fly ash of Chinese mainland, Taiwan and Japan. In fly ash ofChinese mainland Cu and Zn were higher in F2, but Cu existed in F2and zincexisted in F1in the fly ash of Taiwan and Japan.2.Established suitable for MSW fly ash utilization process risk assessmentmethod, and instance simulation study the stabilized before and after wasteincineration fly ash heavy metals ecologica risks and resource in the environment and humangenerating risks.(1)mainly ecological risk determined by the RAC method. Analysis found thatthe inland areas of China, Taiwan and Japan Fly Ash have ecological risk, but risk isdifferent severity. After pretreatment, the RAC value of the fly ash significantlyreduced, in particular after stabilized, the RAC values were less than1%.(2)The risk of resource of fly ash produced during the main study two aspects,namely the process of disposal of fly ash particles escape and leaching of heavymetals and high-temperature calcination volatile toxic substances. Based on theGaussian dispersion model uses two models to analyze the concentration of heavymetals in the fly ash with the changes in the distance, and then through a health riskassessment model to calculate their risk, concluded that:Fly ash piled up in the process of leaching of heavy metals pollution ofgroundwater and cause a risk to human body. f Three areas of fly ash in the piled upprocess will be pollution of groundwater, and inland areas in China>Japan> Taiwan.After pretreatment, risk of heavy metals in fly ash to the human body is significantlylower before processing, especially after stabilizing treatment of fly ash does notconstitute a risk to human body.Fly ash in the piled up process of particulate matter to human body caused therisk is that, first increases then decreases, with increasing distance from the oral intakeof heavy metals by hand is the main way of human risk, including fly ash has thehighest risk value of Taiwan, followed by inland areas in China, the last is Japan.Consider biological effectiveness, acid soluble state of pre-treatment fly ash isadopted to improve the risk assessment, three pretreatment methods have reduced therisk value of the fly ash.The risk of volatilization of heavy metals in fly ash by high temperature resourceis that, three regions in fly ash high temperature utilization process in the maximumlanding concentration all can produce risks to human body, the risk is Taiwan>mainland> Japan.