Wang Lei, Chen Qi, Jamro Imtiaz Ali, Li Rundong, Li Yanlong, Li Shaobai, Luan Jingde
College of Energy & Environment, Shenyang Aerospace University, Shenyang, 110036, China.
Chemical & Biological Engineering, The University of British Columbia, Vancouver, V6T 1Z3, Canada.
Environ Sci Pollut Res Int. 2016 Jun;23(12):12107-19. doi: 10.1007/s11356-016-6320-2. Epub 2016 Mar 11.
Municipal solid waste incinerator (MSWI) fly ashes are characterized by high calcium oxide (CaO) content. Carbon dioxide (CO2) adsorption by MSWI fly ash was discussed based on thermogravimetry (TG)/differential thermal analysis (DTA), minerology analysis, and adapting the Stenoir equation. TG/DTA analysis showed that the weight gain of the fly ash below 440 °C was as high as 5.70 %. An adapted Stenoir equation for MSWI fly ash was discussed. The chloride in MSWI fly ash has a major impact on CO2 adsorption by MSWI fly ash or air pollution control (APC) residues. Geochemical modeling of the critical trace elements copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), and antimony (Sb) before and after carbonation was performed using a thermodynamic equilibrium model for solubility and a surface complexation model for metal sorption. Leaching of critical trace elements was generally found to be strongly dependent on the degree of carbonation attained, and their solubility appeared to be controlled by several minerals. Adsorption on ferrum (Fe) and aluminum (Al) colloids was also responsible for removal of the trace elements Cd, Pb, and Sb. We used Hakanson's potential ecological risk index (HPERI) to evaluate the risk of trace element leaching in general. The results demonstrate that the ecological risk showed a V-shaped dependency on pH; the optimum pH of the carbonated fly ash was found to be 10.3-11, resulting from the optimum carbonation (liquid-to-solid (L/S) ratio = 0.25, carbonation duration = ∼30-48 h). The dataset and modeling results presented here provide a contribution to assessing the leaching behavior of MSWI fly ash under a wide range of conditions.
城市固体废物焚烧炉（MSWI）飞灰的特点是氧化钙（CaO）含量高。基于热重分析（TG）/差示热分析（DTA）、矿物学分析以及对Stenoir方程的修正，讨论了MSWI飞灰对二氧化碳（CO₂）的吸附情况。TG/DTA分析表明，飞灰在440℃以下的增重高达5.70%。讨论了适用于MSWI飞灰的修正后的Stenoir方程。MSWI飞灰中的氯化物对MSWI飞灰或空气污染控制（APC）残渣的CO₂吸附有重大影响。使用溶解度的热力学平衡模型和金属吸附的表面络合模型，对碳化前后关键微量元素铜（Cu）、镉（Cd）、锌（Zn）、铅（Pb）和锑（Sb）进行了地球化学建模。一般发现，关键微量元素的浸出强烈依赖于达到的碳化程度，其溶解度似乎受几种矿物控制。铁（Fe）和铝（Al）胶体上的吸附也有助于去除微量元素Cd、Pb和Sb。我们使用哈坎森潜在生态风险指数（HPERI）来总体评估微量元素浸出的风险。结果表明，生态风险对pH呈V形依赖性；发现碳酸化飞灰的最佳pH为10.3 - 11，这是由最佳碳化（液固比（L/S）= 0.25，碳化持续时间 = ∼30 - 48小时）导致的。此处呈现的数据集和建模结果有助于评估MSWI飞灰在广泛条件下的浸出行为。
