粉煤灰/污泥灰协同固化Pb^(2+)或Zn^(2+)的实验研究  

Experimental Study on Synergistic Solidification of Pb^(2+)or Zn^(2+)by Fly Ash and Sludge Ash

作　　者：李强 邱瑞芳[2] LI Qiang;QIU Ruifang(Sedin Engineering Co.,Ltd.,Taiyuan 030032,China;School of Environmental&Resource Science,Shanxi University,Taiyuan 030006,China)

机构地区：[1]赛鼎工程有限公司,太原030032 [2]山西大学环境与资源学院,太原030006

出　　处：《电力学报》2024年第3期210-220,共11页Journal of Electric Power

基　　金：国家自然科学基金联合基金资助项目(U1910215)。

摘　　要：以粉煤灰和污泥灰为原料,通过碱激发制得地聚物,协同固化Pb^(2+)和Zn^(2+)。研究了Pb^(2+)或Zn^(2+)掺量对地聚物固化体Pb^(2+)或Zn^(2+)浸出效率和抗压强度的影响,利用扫描电子显微镜(SEM)对固化体表观形貌进行了观察和分析,结合X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FT-IR)分析了固化体的化学结构,通过对Pb^(2+)或Zn^(2+)在3种浸出液中的浸出动力学模拟,初步探索了粉煤灰/污泥灰协同固化Pb^(2+)或Zn^(2+)的机制。结果表明:粉煤灰/污泥灰基地聚物对Pb^(2+)和Zn^(2+)具有良好的固定效果,当Pb^(2+)或Zn^(2+)的掺量为0.25%时,固化体在28天最高抗压强度分别达到56.1 MPa和62.2 MPa;在3种浸出液中,Pb^(2+)或Zn^(2+)的固定率大多在99%以上。通过微观分析得知,Pb^(2+)或Zn^(2+)是以羟基配合离子的形式被物理封装在地聚物内部结构中。Pb^(2+)的浸出过程符合球体内扩散模型,反应表观活化能为18.81 kJ/mol;Zn^(2+)的浸出过程受界面扩散和界面反应的混合控制,反应表观活化能为30.95 kJ/mol。该结论可为煤气化渣和污泥等大宗固废的无害化处理和资源化利用拓展新途径。The geopolymer,prepared from fly ash and sludge ash as raw materials by alkali activated,is used for solidification of Pb^(2+)or Zn^(2+).The influence of Pb^(2+)or Zn^(2+)content on Pb^(2+)or Zn^(2+)leaching rate and compres⁃sive strength of solidified geopolymer are investigated.The apparent morphology is observed using scanning electron microscopy(SEM).The chemical structure analysis of the geopolymers by fourier transform infrared spectrometer(FT-IR)and X-ray diffraction(XRD)are tested.Combined with leaching kinetics simulation of Pb^(2+)or Zn^(2+)in the 3 leaching solution,respectively,the leaching mechanism is initially explored.The results show that fly ash/sludge ash based solidifie geopolymers have good fixing effect on Pb^(2+)or Zn^(2+).When Pb^(2+)or Zn^(2+)content is 0.25%,the maximum compressive strength of the solidified geopolymers after 28 days can reach 56.1 MPa and 62.2 MPa,respectively.The fixation rate of Pb^(2+)or Zn^(2+)is mostly above 99%in the three leaching solutions.The microscopic analysis shows that Pb^(2+)or Zn^(2+)is physically encapsulated in the internal structure of the geopolymer in the form of hydroxyl metal complex ions.The leaching process of Pb^(2+)is consis⁃tent with the sphere diffusion model,and the apparent activation energy is 18.81 kJ/mol.The leaching process of Zn^(2+)is controlled by interfacial diffusion and interfacial reaction,and the apparent activation energy is 30.95 kJ/mol.A new way for harmless treatment and resource utilization of bulk solid wastes such as coal gasification slag and sludge is developed.

关 键 词：循环流化床 粉煤灰 污泥灰 地聚物 协同固化 抗压强度 重金属固定率 

分 类 号：TK229[动力工程及工程热物理—动力机械及工程] TU521[建筑科学—建筑技术科学]