摘要
为考察单质(S)、硫化钠(Na_2S)和硫酸钠(Na_2SO_4)对垃圾焚烧过程中重金属铅(Pb)迁移分布的影响,采用ICP-AES测量重金属浓度,并选用HSC Chemistry软件模拟反应进程以及SEM观察反应后微观形貌。结果表明,硫和硫化物对Pb的挥发具有2个方面的影响。一方面,加入的硫和硫化物能够与Pb发生化学反应生成不易挥发的Pb硫酸盐,降低其挥发;另一方面,硫和硫化物的加入形成钠硫酸盐,具有助熔效果,能够降低灰渣的熔点,易于Pb的挥发。受这2个方面因素的综合影响,加入硫和硫化物后,重金属Pb的挥发率高低依次为Na_2SO_4>Na_2S>单质硫。同时还发现,当温度从600℃升至900℃时,生成的Pb硫酸盐逐渐分解,助熔效果增强,硫和硫化物降低Pb挥发的效果减弱。
In this study, the effects of sulfer(S), sodium sulfide(Na2S) and sodium sulphate(Na2SO4) on themigration and distribution of heavy metal (Pb) in the waste incineration process were investigated. ICP-AES wasused to measure the concentration of heavy metal. HSC Chemistry software and SEM were used to simulate thereaction process, identify the microstructure of fly ash, respectively. The result shows that sulfur and sulfideaddition could reduce or promote Pb volatilization. On the one hand, a chemical reaction occurred between Pband the additives of sulfur and sulfide, and a non-volatile salt of PbSO4 was formed, which reduced Pbvolatilization. On the other hand, the addition of sulfur and sulfide led to the formation of Na2SO4, whichfacilitated the melting of the ash, reduced its melting point and promoted Pb volatilization. Influenced by abovetwo factors, the volatilization rate of Pb was Na2SO4> Na2S > S after sulfur and sulfides addition. Moreover, asthe temperature increased from 600 ℃ to 900 ℃, the formed PbSO4 decomposed, the effect of melting facilitationincreased, Pb volatilization reduction became weak accordingly.
作者
徐浩然
张瑞娜
胡济民
吴亭亭
XU Haoran;ZHANG Ruina;HU Jimin;WU Tingting(Key Laboratory of Coal Gasification and Energy Chemical Engineering, Ministry of Education, East China University of Science and Technology,Shanghai 200237, China;Shanghai Environmental Sanitation Engineering Design Institute Co. Ltd., Shanghai 200232, China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2019年第1期169-176,共8页
Chinese Journal of Environmental Engineering
关键词
垃圾焚烧二次污染
焚烧无害化处理
热力学模拟
铅迁移分布
硫和硫化物
secondary pollution in waste incineration
incineration harmless treatment
thermodynamic simulation
migration and distribution of Pb
sulfur and sulfide
