摘要
该文探究了溶解性有机物(DOM)在不同环境p H条件下对稳定化飞灰中重金属(Pb、Zn、Cu、Cd)溶出行为的影响并进行环境风险评估。腐殖酸(HA)和富里酸(FA)浸提环境下p H值均是主导飞灰中重金属浸出的关键因素,且pH越低,浸出浓度越高。DOM会影响浸出重金属在“飞灰-浸出液”体系中的终点浓度分布,但其影响规律因浸提环境(HA或FA)、飞灰类型、重金属种类而异,同时受环境pH的影响。相比HA浸提环境,FA对重金属的终点浓度分布影响波动较大,并无一致性规律。DOM在3种环境pH条件下总体上均减弱了稳定化飞灰重金属的“总体浸出环境风险水平”。酸中和能力(ANC)是维持填埋稳定化飞灰所赋存重金属稳定性的关键,一旦飞灰的ANC被酸性pH环境所耗尽,螯合剂或磷酸稳定化作用以及DOM的减弱作用均难以阻碍重金属浸出环境风险的再次增加。研究结果能够为非规范填埋条件下(如因未严格分区填埋存在酸性有机渗滤液入侵现象)稳定化飞灰中重金属浸出行为评价及环境风险管控提供科学依据。
This paper intended to explore the effects of DOM(dissolved organic matter)on the behavior of leaching of heavy metals(Pb,Zn,Cu,Cd)in stabilized fly ash under different environmental pH conditions,and to perform the corresponding environmental risk assessment.It was found in the experiment that pH value under the condition of leaching with HA(humic acid)and FA(fulvic acid)was the key factor of the leaching of heavy metals in fly ash,i.e.,the lower the pH,the higher the heavy metals concentration in leachates.Besides,DOM would affect the end-point concentration distribution of leached heavy metals in the fly ash/leachate system,but the law of its influence varied with the leaching environment(in HA or FA),fly ash type,and heavy metal species,and would be affected by environmental pH.Compared with leaching with HA,the effect on the end-point concentration distribution of heavy metals in FA environment fluctuated rather strong,but with no regularity.In general,DOM could weaken the overall leaching environmental risk level of heavy metals in stabilized fly ash under the condition of environmental p H,and ANC(acid-neutralizing capacity)was critical to maintaining heavy metals’stability of stabilized fly ash in the landfill-once ANC of flyash was exhausted by acidic pH environment,both the stabilization effect of chelating agent and phosphoric acid and the weakening effect of DOM were difficult to prevent the re-increase of environmental risk of the leaching of heavy metals.Consequently,the experimental study could provide the scientific basis for evaluating the behavior of heavy metals leaching of the stabilized fly ash and environmental risk management/control,especially in the scenario of the non-standardized landfills wherein the invasion of acidic organic leachate may exist due to the lacking of strict zoning landfills.
作者
于倩雯
吴寅凯
尹俊权
李卫华
孙英杰
葛燕辰
何依洋
YU Qianwen;WU Yinkai;YIN Junquan;LI Weihua;SUN Yingjie;GE Yanchen;HE Yiyang(Qingdao Solid Waste Pollution Control and Resource Engineering Research Center,School of Environmental and Municipal Engineering,Qingdao University of Technology,Qingdao 266520,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2022年第12期174-181,共8页
Environmental Science & Technology
基金
国家自然科学基金项目(52000111,51978350)
山东省博士后创新项目(202103026)
青岛市博士后应用研究项目(2020年7月)。
