| With rapid economic development and urbanization, the quantity of municipal solid waste (MSW) generated has increased quickly. Expanding MSW production could have a great effect on the environment and public health as the disposal of MSW has become a serious problem in China and other countries around the world. Thermal treatment using incineration technology has proven as an attractive method of MSW disposal for many years. Due to the limitation of MSW management system in China, many components in MSW which could be recycled as resource were loss during combustion. It goes against the goal for establishing "Recycking-based Society". On the other hand, MSW incineration in China is still in initial stage. Due to the complex characteristics of Chinses MSW, secondary pollution from MSW incineration has been a serious problem. In this research, a newly source-classication and transportation system was established. The operation MSW incineration, formation and pollution control of PCDD/Fs and PAHs, transfer and transformation of heavy metals during MSW incineration process were studied. Furthmeore, the ultilzaion of residues from combustion was also dicussed. Main conclusions were:(1) Based on the variation trend of MSW, recycling and ultization of waste, and feasibility of methods, MSW should be sorted as food waste, dry waste and harmful waste by residents. The whole system including collection, transfert and ransportation were optimized. A transfer station was designed and constructed for MSW recycling, and the combined dewatering technology" vehicle compress dewatering +mechanical dewatering + stockpile dewatering" was established. A management system were founded as well. It was shown that the separeation methods was feasible, and the correctness rates of MSW separatione increased significantly. The components of MSW changed due to the classification and recycling. Although the moisture and bulk density increased, but with a higher dewatering efficiency (more than 14%) the moisture of the classified MSW reduced significantly.(2) Due to reduction in source classification and separation section, conten of paper, textile and plastics decreased, plastics signicifantly lessend by 50% in particular. Kichetn waste became the main component. Cl content was decreased, which was dierectly related with the removal of a large amount od plastic bags and PVC, and the reduction of soluble chloride contaning in food waste through dewatering. The lower heat value (LHV) of feeding waste was increased to more than 5000kJ/kg, resulted from combined dewatering. The treatment efficiency of incinerator was improved and the temperature of incinerator furnace was continuously higher during the combustion process. By the newly established MSW source-classified collection and incineration system, the net enery output of the waste heat boiler increased significantly. Therefore, the energy transformation efficiency between waste heat boiler and steam turbine generator improved.(3) The concentration distribution and toxic equivalent quantity (TEQ) of 7 kinds of 2,3,7,8-substituted PCDDs congeners and 10 kinds of 2,3,7,8-substituted PCDFs congeners in flue gases from incinerator and the stack flue gases were studied. The ratio of PCDDs and PCDFs changed in stack flue gas compared with flue gas. 2,3,4,7,8-PeCDF was the key factor affecting the TEQ. The correlation relationship between the PCDD/Fs concentrations in flue gas and the removal quantity of PCDD/Fs in the air pollution control devices (APCD) was observed, which proved that the PCDD/Fs concentration distribution and the absorption load of active carbon were the two key factors affecting the removal efficiency of PCDD/Fs. The most toxic congener 2,3,7,8-TCDD was condensed in fly ash from bag filter (FABF). The proportion of coplanar PCBs TEQ /dioxin TEQ of FABF was less than 1%, which indicated that TEQ of PCDD/Fs was the dominant factor affecting the dioxin TEQ of FABF. The characteristcs of feeding waste and the incineration parameters principally influenced PCDD/Fs formation during combustion. Content of O2,CO,HCl in flue gas were decreased. The correlation relationship between PCDD/Fs and content of O2,CO,HCl in flue gas existed. These results demonstrated that PCDD/Fs formation in flue gas could be reduced, and concentrated in fly ash to lessen the emission to atmosphere with the foundation of the new MSW source-classified collection and incineration system. Furthermore, the emission factor of dioxin from the plant was reduced to 338.92 ng I-TEQ/t MSW.(4) Distributions of 16 PAHs and 7 carcinogenic PAHs among BA, FAB and FABF were studied. PAHs were mainly concentrated in BA. The concentrations of PAHs in fly ashes were relatively lower. The ranking of the total content of PAHs, the total content of carcinogenic PAHs and the toxic equivalency of PAHs (B[a]Peq) all were: BA > FAB > FABF. The constitution of PAHs in FAB were the similar. The total content of PAHs and B[a]Peq of bottom ash and fly ash from the classified MSW incineration were both decreased. Chlorine was the key factor that affecting PAHs formation during MSW combustion. Removal of metals and paper printed with heavy metal containing materials might reduce PAHs generation from MSW incineration. Therefore, sorting of plastics and metal, combined dewatering were the two important steps for reducing PAHs formation. Becasue PAHs are typical products of imcomplete combustion, and PAHs formation are sensitive to the combustion process. A negative correlation between the total PAHs and furnace temperature was observed, which proved that the increase of furnace temperature during the classified MSW incineration was one of important factors for reducing PAHs generation. Moreover, a positive correlation between the total PAHs and CO, a negative correlation between the total PAHs and excess air ratio were shown. The increase of combustion efficiency which was presented as decrease of CO and increase of excess air ratio, might significantly decrease the PAHs formation.(5) Transfer and distribution of heavy metals in bottom ash and fly ash during MSW incineration were studied. Low volatile metals such as Cu,Cr,Ni,Mn mainly exsited in bottom ash. On the other hand, some volatile metals such as Hg, Cd, Zn and Pb, would evaporate and would be adsorpt by granule of fly ash during condensation process. Therefore, these volatile metals became rich in fly ash. Levels of heavy metals in residues are affected by feeding waste and combustion history, especially incineration temperation. Concentations of heavy metals in bottom ash were lower, probably due to the reduction of metals, metal-containing newpaper and textile in feeding waste. Volatile metals are expected to have higher transfer rate to fly ash as furnace temperature increases. Owing to the continuously higher in the incinerator furnace during the incineration of classified MSW, heavy metals concentrations in fly ashes were higher. The maximum leachable abilities of heavy metals were related with chemical special distribution of heavy metals in residues. There was a linear relationship between the maximum leachable abilities and the total content of four leacheable chemical speciations, that were water soluble, Ca exchangeable, Ag exchangeable and acid soluble, respectively. Under the newly established MSW source-classified collection and incineration system, the enrichment of heavy metals in fly ash may be advantageous for emission decrease of heay metals to atmosphere. On the hand, the decrease of leacheable chemical speciations in fly ash could be beneficial to reduce the ecological risk of heavy metals leachting, where fly ash treated specilly as hazardous waste.(6) As the results of volcanic activities testing for bottom ashes and fly ashes from MSW incineration, BA might be able to be applied as pozzolanic material due to its qualified activity of volcanic ash. According to chemical component analysis of BA in oxide form, particularly the distribution of SiO2,CaO,Al2O3 which primarily affected the characteristics of pozzolanic cement, and the effect of BA on strength of concrete and fluidity of cement mortar, it was shown that the rupture strength, compressive strength and activity index of C-BA increased, fluidity of cement mortar decreased. In addtion, loss in ignition of BA decreased but property of grindability was improved. These might be due to the change of component of feeding waste, much more complete decomposition of organic matter and decrease of size distribution for BA, which were directly releated to the higher furnace temperature of the classified MSW incineration process. The results indicated that the newly established MSW source-classified collection and incineration system could improve the pozzolanic characteristics of BA as pozzolanic materials used for cement production, and therefore it could be conducive to BA utilization in cement and construction industry.
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