Study on the Useful of Scrubber Residue from Municipal Solid Waste for the Concrete Products

城市生活垃圾(MSW)焚烧干法洗涤系统中的洗涤器残渣经过中间处理后，大部分被处理在地面上。因为垃圾焚烧炉残渣与水接触时会显示出高的pH值，而且会产生高密度的氯化物，铅等重金属会被淋滤掉。然而，近年来由于填埋场的短缺和环境污染，要求对垃圾焚烧炉残渣进行资源化处理。本报告研究了垃圾焚烧残渣对混凝土中钢筋的腐蚀和混凝土中重金属的淋溶作用。为了研究生活垃圾对碳化过程和氯离子渗透的影响，进行了加速碳化试验和盐雾试验。在实验中，水灰比分别设置为0.35和0.55。垃圾取代水泥的比例分别为0%、10%和20%。采用引气型高效减水剂补偿城市生活垃圾混凝土坍落度损失。试验结果表明：(1)对于焚烧飞灰的浸出，铅随老化而降低，而铅和氯离子则因焚烧飞灰的洗涤而降低。(2)掺入焚烧飞灰的混凝土的抗压强度与不含飞灰的混凝土相当。含老化焚烧飞灰混凝土的碳化深度和氯离子含量均随灰分含量的增加而增大。(4)当焚烧飞灰中氯离子含量较高时，钢筋锈蚀加速。(5)掺入老化焚烧飞灰的混凝土中铅的洗脱满足环境要求。

Scrubber residue of dry scrubber systems from combustion of municipal solid waste (MSW) are almost disposed in ground after the intermediate process. Because MSW incinerator residue show high pH values when brought in contact with water, and high-density chloride, and heavy metals such as Pb are leached. However, the resource recycling of MSW incinerator residue are recently required because of the shortage of the land fill lot and the environmental pollution. This report investigates the role of MSW incinerator residue on the corrosion of steel bars in concrete, and leaching heavy metals from concrete. To study the effects of MSW on the carbonation process and the chloride penetration, the accelerated carbonation test and the salt spray test were performed. In the experiments, the water-cement ratios were set to 0.35 and 0.55. The percentages of cement replacement by MSW were selected as 0, 10 and 20 % weight. Slump loss of MSW concrete was compensated by the use of a air-entraining and high-range water-reducing agent.The results of the experiments are summarized as follows:(1) As for leaching of incineration fly ash, Pb is reduced by aging, while Pb and Cl^- are reduced by washing of incineration fly ash.(2) The compressive strength of concrete containing incineration fly ash is comparable to that of concrete with no fly ash, though the values slightly vary depending on the fly ash treatment method.(3) Both the carbonation depth and chloride content of concrete containing aged incineration fly ash tend to increase as the ash content increases.(4) Corrosion of reinforcing steel is accelerated when the chloride ion content in the incineration fly ash is high.(5) The Pb elution from concrete containing aged incineration fly ash satisfies the environmental requirement.