CO2去除垃圾焚烧飞灰水洗液中Pb和Zn的工艺条件

为探明CO₂对飞灰水洗液中Pb和Zn的去除效果,研究了CO₂浓度、通入时间、流速以及体系反应温度和重金属离子初始浓度对Pb和Zn在水洗液中沉淀的影响.结果表明:水洗液中Pb和Zn的初始浓度越低,通入CO₂后Pb和Zn的残留率越低；增大CO₂浓度、延长通入时间、增大流速以及降低体系反应温度,均可有效降低Pb和Zn的残留率；CO₂沉淀处理在最佳工艺条件〔CO₂浓度为10%(φ)、通入时间为80 s、流速为2 mL/min以及体系反应温度为40~50 ℃〕下,Pb和Zn的残留率分别降至3%和0.1%以下. 

Process Conditions of Pb and Zn Removal from Washing Solution of Municipal Solid Waste Incinerator Fly Ash by CO2

In order to investigate the removal efficiencies of Pb and Zn from the washing solution of fly ash by CO2,the effect of CO2 concentration,feeding time,flow rate,system reaction temperature and heavy metal initial concentrations on Pb and Zn sedimentation in the washing solution were studied.The results showed that decreasing initial concentrations of Pb and Zn in the washing solution resulted in decreasing residue rates of Pb and Zn after feeding CO2.Increasing CO2 concentration,feeding time,or flow rate,or reducing system reaction temperature,all effectively decreased the residue rates of Pb and Zn.The residue rates of Pb and Zn reached less than 3% and 0.1% respectively when the optimal process conditions of CO2 precipitation treatment were CO2 concentration 10%,feeding time 80 s,flow rate 2 mL/min and system reaction temperature 40-50 ℃.