摘要
采用水泥、粉煤灰及有机硫稳定剂DTCR固化/稳定化处理重金属污染的底泥,考察固化体的抗压强度及重金属浸出毒性,确定了底泥固化/稳定化的最佳工艺条件。结果表明:仅用水泥固化/稳定化重金属污染底泥,固化体抗压强度随水泥用量的增加而上升,重金属浸出浓度则下降,当水泥∶干底泥质量比为0.6∶1.0时,固化体7 d抗压强度能达到0.99 MPa的标准值;进一步研究发现,水泥∶粉煤灰∶干底泥质量比为0.54∶0.06∶1.0时,重金属浸出浓度有所上升,但7 d及28 d抗压强度仍能分别达到1.2 MPa和2.8 MPa;加入DTCR后,当水泥∶粉煤灰∶DTCR∶干底泥质量比为0.54∶0.06∶0.012∶1.0时,固化体7 d及28 d抗压强度分别为1.1 MPa和2.1 MPa,醋酸缓冲溶液法浸出的Cd、Pb、Zn和Cu浓度分别为0.102、0.189、0.180和0.032 mg/L。
A cement-fly ash-dithiocarbamate（DTCR）system was used to solidify and stabilize （S/S） river bottom sediments containing heavy metals, the optimum conditions were selected by testing of compressive strength and leaching toxicity. The results demonstrated that with the dosage of cement increased, compressive strength of the solidified products was also enhanced, but the concentration of heavy metals in leaehate decreased. When the ratio of cement to dried sediment reached to 0.6, the compressive strength of the cement solidified products （after 7 d） was higher than the standard value of 0.98 MPa. Further studies showed that the compressive strengths of solidified products from 7 d and 28 d were 1.2 MPa and 2.7 MPa, respectively, when the mass ratio of cement： flyash： sediment was 0.54： 0.06： 1.0, however the leaching concentration of heavy metal increased. When cement： flyash： DTCR： sediment was 0.54： 0.06： 0. 012： 1.0, the compressive strengths of solidified products from 7 d and 28 d could reach to 1.1 MPa and 2. 1 MPa, respectively. And after handled with the acetic acid buffer solution method the leaching concentration of Cd, Pb, Zn and Cu were 0. 102, 0. 189, 0. 180 and 0. 033 mz/L. resnectivelv.
出处
《环境工程学报》
CAS
CSCD
北大核心
2013年第3期1121-1127,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(30970105和51078131)
国家"水体污染控制与治理"科技重大专项(2009ZX07212-001-02)
长沙科技计划重点资助项目(K0802151-31)
关键词
重金属
污染底泥水泥粉煤灰DTCR抗压强度
浸出浓度
heavy metal
contaminated sediment
cement
fly ash
DTCR
compressive strength
leac-hing concentration
