Abstract:

The contents of total chlorine, inorganic/organic chlorine and volatile/non-volatile chlorine in municipal solid waste (MSW) components were determined by the oxygen bomb method, extraction-oxygen bomb method and tube furnace-oxygen bomb method, respectively. Based on which, the speciation of chlorine in MSW and its transformation during thermal treatment of MSW were investigated. The results show that the contents (dry basis) of total chlorine in the MSW components range from 1.52 mg/g to 19.44 mg/g, of which the contents of chlorine in the food waste components are the highest, 8.38—19.44 mg/g, followed by the rubber/plastic components, 3.51—10.60 mg/g. The higher chlorine contents in some paper and textile components are related to the cross-contamination by food waste, while the contents of chlorine in the other components are lower. Source separation of food waste can significantly lower the chlorine content in MSW. The inorganic chlorine accounts for more than 90% of the total chlorine in the food waste components, while the organic chlorine accounts for 46%—55% of the total chlorine in the rubber/plastic components. The content and speciation of chlorine in different components of MSW from different transfer stations vary greatly, which indicates the complexity of chlorine occurrence in MSW. During thermal treatment, about 65% of chlorine in the rubber/plastic components and 59%—71% of chlorine in the paper components are transformed to volatile chlorine under air atmosphere, respectively. Under nitrogen atmosphere, the non-volatile chlorine in the food waste components accounts for 38%—69%, the volatile chlorine in the rubber/plastic components and paper components accounts for 42%—60% and 56%—71%, respectively. The inorganic chlorine tends to be converted into volatile chlorine and non-volatile chlorine under air atmosphere, and into non-volatile chlorine and other chlorine compounds under nitrogen atmosphere; while the organic chlorine is mainly converted to the volatile chlorine. It can provide theoretical basis and solution for flue gas cleaning and chlorine corrosion prevention during thermal treatment process of MSW by revealing the occurrence of chlorine in MSW and its transformation during thermal treatment.

Key words: municipal solid waste, speciation of chlorine, thermal transformation, waste treatment, distribution, absorption

摘要：

采用氧弹法、浸提-氧弹法和管式炉-氧弹法分别测定生活垃圾组分中的总氯、无机/有机氯以及挥发态/固定态氯的含量，探究了生活垃圾中氯的形态和在热处理过程中的转化规律。结果表明，生活垃圾各组分的总氯含量（干基）为1.52~19.44 mg/g，其中，厨余类组分的氯含量最高，为8.38~19.44 mg/g。厨余类组分的无机氯含量占比高达90%以上，橡塑类组分的有机氯含量占比为46%~55%。热处理过程中，无机氯在空气气氛下更易转化成挥发态氯和固定态氯，在氮气气氛下更易转化成固定态氯和其他态氯；而有机氯则主要转化成挥发态氯。揭示生活垃圾各组分的氯形态及其在热处理过程中的转化规律，可以为生活垃圾热处理过程烟气处理和氯腐蚀控制提供理论依据和解决思路。

关键词: 生活垃圾, 氯形态, 热转化, 废物处理, 分布, 吸收