垃圾焚烧过程中硫及硫化物在含氯体系下对Pb迁移特性的影响  

Effects of sulfur and sulfide on Pb migration in the chlorine-containing system during MSW incineration

作　　者：吴亭亭[1] 李彪 WU Ting-ting;LI Biao(Department of Energy and Chemical Engineering,School of Resource and Environmental Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学资源与环境工程学院能源化工系,上海200237

出　　处：《安全与环境学报》2022年第4期2209-2216,共8页Journal of Safety and Environment

摘　　要：为考察垃圾焚烧过程中硫及硫化物(S、Na_(2)S和Na_(2)SO_(4))在添加氯(NaCl、PVC)的条件下对Pb迁移特性的影响,采用管式焚烧炉模拟城市生活垃圾焚烧过程,在垃圾原料中分别添加质量分数1%的NaCl或PVC作为含氯体系,硫及硫化物的添加质量分数为0、1%、2%、3%。使用ICP-AES测量焚烧过后各组分中Pb的含量,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:硫及硫化物的加入一方面可以与Pb反应生成不易挥发的Pb硫酸盐及提供钠与体系中的氯结合,减少易挥发性Pb氯化物的生成,从而抑制Pb的挥发,抑制效果由大到小为Na_(2)S、Na_(2)SO_(4)、S;另一方面钠硫酸盐具有助熔作用,能够降低灰渣的熔点,易于Pb的挥发,促挥发效果由大到小为Na_(2)SO_(4)、Na_(2)S、S,且体系中添加熔点更低的NaCl可以降低钠硫酸盐发生共晶熔化的温度,硫及硫化物会在更低的温度条件下表现出促挥发作用。受这两方面因素的综合影响,硫及硫化物在不同的焚烧温度下对Pb的挥发率表现出不同的影响特性,当温度从600℃升至900℃时,生成的Pb硫酸盐逐渐分解,逐渐释放出的氯离子与Pb结合,熔渣作用增强,硫及硫化物的加入对Pb由抑制挥发作用逐渐转变为促进作用。To investigate the effects of sulfur and sulfide(S,Na_(2)S and Na_(2)SO_(4)) on the migration characteristics of Pb under the conditions of chlorine addition(NaCl,PVC)during waste incineration,a tubular incinerator was used to simulate the municipal waste incineration process.1%mass fraction of NaCl or PVC was added to the waste material as the chlorinecontaining system,and the mass fractions of sulfur and sulfide addition were 0,1%,2%and 3%.ICP-AES was used to measure the Pb content in each component after incineration,HSC Chemistry software was used to simulate the reaction process,and SEM was used to observe the microscopic morphology after the reaction.The experimental results show that the addition of sulfur and sulfide can,on the one hand,reduce the generation of volatile Pb chloride by reacting with Pb to generate non-volatile Pb sulfate and providing sodium to combine with chlorine in the system,thus inhibiting the volatilization of Pb,and the inhibition effect was Na_(2)S>Na_(2)SO_(4)>S;on the other hand,sodium sulfate has a fluxing effect,which can lower the melting point of ash and facilitate the volatilization of Pb,and the pro-volatilization effect was Na_(2)SO_(4)>S.The volatilization effect is Na_(2)SO_(4)>Na_(2)S>S,and the addition of a lower melting point of NaCl in the system can reduce the temperature of eutectic melting of sodium sulfate,sulfur and sulfide will show the volatilization effect under lower temperature conditions.Under the combined influence of these two factors,sulfur and sulfide show different influences on the volatilization rate of Pb at different incineration temperatures.When the temperature increases from 600℃to 900℃,the generated Pb sulfate gradually decomposes,chloride ions gradually release to combine with Pb,the slagging effect is enhanced,and the addition of sulfur and sulfide gradually changes from inhibiting the volatilization of Pb to promoting it.

关 键 词：环境工程学 垃圾焚烧 硫及硫化物 含氯体系 Pb迁移特性 

分 类 号：X705[环境科学与工程—环境工程]