Study On Emission Characteristics Of Inorganic Chlorine And PCDD/Fs During The Process Of Typical Medical Wastes Components Pyrolysis-incineration

The amount of medical waste (MW) has rapidly increased in recent years with the development of the healthcare facilities. MW containing a great quantity of bacteria and viruses, is toxic and infectious. Therefore the disposal of MW has aroused more and more widespread concern. Pyrolysis-incineration technology is considered to be the most effective way to dispose of MW. However, qunatities of contaminations such as HCl and dioxins are generated during MW incineration due to its high chlorine content. Based on the above background, this paper carried out a study on inorganic chlorine release and dioxins emission from the process of typical medical waste components pyrolysis-incineration, expecting to provide the certain help to medical waste disposal and pollution control.The thermogravimetric behavior and gas production characteristics of typical medical waste components were investigated by TG-FTIR under nitrogen and oxygen atmosphere. The results show that different single-component has different thermal degradation characteristics and pyrolysis gas compositions. Some strong or weak interactions may exist between the different components of the mixture.In order to investigate the characteristics of inorganic chlorine release and dioxins emission during medical waste pyrolysis-incineration process, a series experiments with different pyrolysis temperature, combustion temperature and gas flow rate were conducted. The relevance among HCl, Cl2and PCDD/Fs emissions was also discussed. The results indicate that:compared to the single PVC incineration, the addition of fiber can obviously promote Cl2formation, while slightly prevent HCl release; HC1emission is significantly reduced by the presence of rubber, the conversion rate of HCl decreased. The de novo synthesis mechanism is dominant in the PCDD/Fs forming pathway during WM combustion process. HxCDF and PeCDF give the greatest contribution to the total I-TEQ value. There are no obvious correlation among HCl, Cl2and PCDD/Fs emission.Co-combustion of MW with ammonium sulfate and urea were also studied in order to investigated and found that both of them can reduce CI2and PCDD/Fs emissions.