CAJ | 학술논문

采用超临界水氧化降解PVC同时无害化处理医疗垃圾焚烧飞灰,利用PVC脱氯形成的中间产物盐酸提取医疗垃圾焚烧飞灰中的重金属,达到飞灰无害化的目的.结果显示,超临界水可以将飞灰颗粒打碎,从而提高盐酸提取重金属的速率和效果,但是在超临界水中还存在重金属的固定过程,过长的反应时间和过高的反应温度都会降低重金属的提取效率.在提取过程中,Cu和Zn优先于Pb被盐酸浸出,而Pb被浸山后很容易被超临界水进一步固定.综合考虑重会属在趟临界水中的变化特性,总结出超临界水处理飞灰和PVC的最佳条件为:PVC与飞灰质量比0.5:1,温度400℃,提取时间90 min.处理后的飞灰再次经过水洗后,其重金属浸出浓度低于USEPA规定的限制值.本研究为飞灰的无害化处理提供一条新的思路.
채용초림계수양화강해PVC동시무해화처리의료랄급분소비회,이용PVC탈록형성적중간산물염산제취의료랄급분소비회중적중금속,체도비회무해화적목적.결과현시,초림계수가이장비회과립타쇄,종이제고염산제취중금속적속솔화효과,단시재초림계수중환존재중금속적고정과정,과장적반응시간화과고적반응온도도회강저중금속적제취효솔.재제취과정중,Cu화Zn우선우Pb피염산침출,이Pb피침산후흔용역피초림계수진일보고정.종합고필중회속재쟁림계수중적변화특성,총결출초림계수처리비회화PVC적최가조건위:PVC여비회질량비0.5:1,온도400℃,제취시간90 min.처리후적비회재차경과수세후,기중금속침출농도저우USEPA규정적한제치.본연구위비회적무해화처리제공일조신적사로.
This study investigated the feasibility of supercritical water(SCW) treatment on synchronous detoxification of medical waste ( MW) incinerator fly ash and PVC. The main merit was that hydrocloric acid could be formed during dechlorination of PVC in supercritical water which was effective for heavy metals extraction. SCW could destroy ash particles, thus improved heavy metals extraction efficiency and velocity. However, SCW also had the effect of fixing metal ions into the ash matrix, hence over time or extremely high temperature treatment conversely lowered heavy metal extraction efficiency. During the treatment process, the extraction of Cu and Zn by HCl was prior to Pb, and Pb could be easily solidified in SCW. Considering the changing properties of heavy metals, it was concluded that the optimum SCW treatment conditions were; PVC/ash ratio =0.5:1 (by weight) , temperature = 400 ℃ and treatment time = 90 min, respectively. Heavy metals leaching from the treated ash was below the USEPA standard limits after further washing with water. This study provides a new potential approach for fly ash detoxification.