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

城市生活垃圾焚烧产生的干式洗涤系统的洗涤残渣经过中间处理后，基本上都是就地处理。由于城市生活垃圾焚烧炉残渣与水接触时pH值高，氯化物浓度高，铅等重金属被浸出。然而，由于垃圾填埋场用地不足和环境污染等原因，垃圾焚烧炉渣资源化利用成为迫切需要。本文研究了城市生活垃圾焚烧残渣对混凝土中钢筋的腐蚀和重金属的浸出作用。为研究城市生活垃圾对碳酸化过程和氯离子渗透的影响，进行了加速碳酸化试验和盐雾试验。在实验中，水灰比设定为0.35和0.55。将MSW取代水泥的百分比选择为0、10和20重量%。研究结果表明：（1）焚烧飞灰的浸出过程中，通过老化降低了Pb的含量，通过水洗降低了Pb和Cl^-的含量; (2)含有焚烧飞灰的混凝土的抗压强度与不含飞灰的混凝土的抗压强度相当，尽管该值根据飞灰处理方法略有不同。(3)老化焚烧飞灰混凝土的碳化深度和氯离子含量均随飞灰掺量的增加而增加。(4)焚烧飞灰中氯离子含量较高时，会加速钢筋的腐蚀。(5)含老化焚烧飞灰的混凝土中铅的溶出符合环保要求。

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.