热等离子体熔融固化模拟医疗废物的研究

Study on Vitrification of Simulated Medical Wastes by Thermal Plasma

利用直流双阳极等离子体实验装置熔融固化处理不同组成的模拟医疗废物.研究了医疗废物熔融过程中重金属的迁移特性、熔渣的重金属浸出特性以及实验系统对医疗废物的处理效果.结果表明,经熔融处理得到的熔渣均呈典型的玻璃质结构,微观结构紧密、光滑且无空隙;所采用的等离子体对医疗废物中重金属有很好的固化效果,固化率在68.5%～89.4%之间;重金属Cd的浸出浓度低于仪器最低检测限,无法检出,Ni、Cr、Zn、Cu和Pb在熔渣中浸出浓度均远低于国家规定的毒性浸出标准.说明热等离子体技术是一种处理医疗废物的有效手段.

The simulated medical wastes with different feed compositions were vitrified in a thermal plasma reactor,the core of which was a DC double anode plasma torch.The purpose of this study was directed towards the mobility characteristics of heavy metals contained during the vitrification process,the leaching behavior of heavy metals in the vitrified slag and the effectiveness of vitrification were investigated.Results indicated that the morphology of vitrified slag was amorphous state which showed the mostly glassy slag of SiO2 and the microstructure of slag was very compact.This thermal plasma could be effectively utilized for encapsulation of heavy metal in wastes,as the vitrification ratio was between 68.5%-89.4%.Toxicity characteristic leaching procedure results showed that the slag had an excellent resistance against leaching of heavy metal ions.Except that the leaching concentration of Cd was lower than the detecting limit,those of Ni,Cr,Zn,Cu and Pb were much lower than that specified in relevant national standards.These results indicate that,with the proper feed compositions,the thermal plasma disposition is an alternative technology with a highly efficiency to dispose medical wastes.