摘要
生活垃圾焚烧飞灰中重金属对环境产生较大危害,而对其的固化/稳定化成为飞灰处理处置中的首要问题。用普通硅酸盐水泥处理垃圾焚烧飞灰较为普遍,为降低能耗提高产品效益,研究了新型大分子有机螯合剂哌嗪-N,N’-双二硫代羧酸钠(TS300)协同不同用量的水泥(30%、40%)固化飞灰中重金属的能力。探究了TS300对目标重金属Zn、Cd、Cr、Pb、Ni的浸出浓度、化学形态和微观结构的影响。结果表明:TS300协同水泥可有效固定飞灰中的重金属,降低浸出浓度60%以上;重金属Cr、Cd、Pb、Ni经固化后的化学形态整体向更稳定的方向移动;随着TS300和水泥添加量的增大,固化块晶体组成更稳定、抗酸强度上升且孔隙致密度增加,其中水泥添加量40%、TS300添加量8%的固化块重金属浸出浓度最低,固化效果最佳。综上,探究TS300协同水泥固化/稳定化重金属的效果和机理,有利于探究不同飞灰处理处置方式的优劣,分析水泥协同药剂固化稳定化飞灰重金属的效果,降低填埋场渗滤液的环境风险,为后续飞灰重金属螯合剂的研发提供新思路。
Heavy metals in fly ash from municipal solid waste incineration are major environmental hazard,and their solidification/stabilization have become the primary problem in fly ash treatment and disposal.Portland cement is commonly used to treat waste incineration fly ash.In order to reduce energy consumption and improve product efficiency,the ability of a new macromolecular organic chelator,sodium piperazine-N,N'-bis-dithiocarboxylate(TS300),to solidify heavy metals in fly ash in concert with different amounts of cement(30%,40%)was investigated.The effects of TS300 on the leaching concentration,chemical morphological changes,and microstructure of the target heavy metals Zn,Cd,Cr,Pb,and Ni were investigated.The results showed that TS300 co-cement could effectively immobilize the heavy metals in fly ash and reduce the leaching concentration by more than 60%.The chemical morphology of heavy metals Cr,Cd,Pb and Ni moved to a more stable direction overall after solidification.With the rise of TS300 and cement addition,curing block crystal composition,acid resistance strength,and pore density increased.The curing block with 40%addition of ordinary silicate cement and 8%addition of TS300 had the lowest heavy metal leaching concentration and the best curing effect.In summary,investigating the effect and mechanism of TS300 co-cement solidification/stabilization of heavy metals could analyze the effect of cement synergistic agents in curing and stabilizing fly ash heavy metals,reduce the environmental risk of landfill leachate,and provide new ideas for the subsequent research and development of fly ash heavy metal chelating agents.
作者
慕宗宇
杨玉飞
王菲
郭明坤
黄启飞
杨延梅
罗中力
MU Zongyu;YANG Yufei;WANG Fei;GUO Mingkun;HUANG Qifei;YANG Yanmei;LUO Zhongli(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences;State Environmental Protection Key Laboratory of Hazardous Waste Identification and Risk Control,Chinese Research Academy of Environmental Sciences;School of River and Ocean Engineering,Chongqing Jiaotong University;Organic Materials Research Laboratory,Tosoh Corporation)
出处
《环境工程技术学报》
CAS
CSCD
北大核心
2024年第1期174-183,共10页
Journal of Environmental Engineering Technology
基金
国家重点研发计划项目(2021YFE0112100)。
