两种医疗垃圾焚烧炉的灰渣特性研究

为评价医疗垃圾焚烧灰渣对环境的危害性及寻找安全有效的处理方法,利用X-射线荧光光谱仪、X射线衍射仪、扫描电镜、原子吸收光谱仪等仪器分别对回转窑式、固定床式医疗垃圾焚烧炉的布袋飞灰及底渣进行化学成分、物相、微观形貌、重金属含量及渗沥行为等特性分析.结果发现,回转窑式和固定床式布袋飞灰热灼减率分别为31.2%、34.6%,两者Cl、SO3和碱金属含量均较高,主要物相为CaSO4和NaCl,且Cd、Zn、Pb等重金属渗沥浓度均超过危险废物填埋允许限值,其渗沥行为可能与布袋飞灰的不规则多孔海绵状微观形貌有一定关系;2种底渣主要由复杂硅酸盐构成,其渗沥浓度低于危险废物规定的阈值.因此,2种布袋飞灰经预处理后方能进入危废填埋场填埋,2种底渣可按一般工业固废直接填埋.

Study on characteristics of ash and slag from two kinds of hospital waste incinerations

In order to evaluate the environmental hazards of hospital waste incinerator ash and slag and probe safety and effective way of processing, the characteristics such as the chemical composition, mineralogy, morphology, metal contentS and leaching behavior of heavy metal etc have been respectively analyzed on the bag fly ash and bottom slag in gyration kiln and fixed bed by using XRF, XRD, SEM and AAS. Results show the loss on ignition of the bag fly ash in gyration kiln and fixed bed is respectively 31.2% and 34.6% , and they have high contents of chloride, sulphate, alkila metal which the major crystalline phases is CaSO4 and NaCl. Moreover, The leaching concentratio of Cd ,Zn and Pb in bag fly ash exeeds the landfill allowable thresholds of the hazardous waste, the leaching behaviors of heavy metals are possibly realted to the irregular sponge-like porous particles with smaller spheres. Besides, the bottom slag mainly consistes of silicates with low leachability , so it may be classfied as non-hazardous wastes.