| 韩超,申向东,薛慧君,樊浩伦,王仁远,刘倩,刘政.镉污染土在水泥-粉煤灰-石灰共同作用下固化效果及孔隙特征[J].农业环境科学学报,2017,36(4):686-693. |
| 镉污染土在水泥-粉煤灰-石灰共同作用下固化效果及孔隙特征 |
| Curing effect and pore characteristics of cadmium contaminated soil under the action of cement-fly ash-lime |
| 投稿时间：2016-12-05 |
| DOI：10.11654/jaes.2016-1552 |
| 中文关键词: 镉污染 水泥/粉煤灰/石灰 固化 无侧限抗压强度 淋滤 孔隙 |
| 英文关键词: cadmium pollution cement/fly ash/lime curing unconfined compressive strength leaching porosity |
| 基金项目:国家自然科学基金项目（51569021）；内蒙古自治区博士研究生科研创新重点项目（B20161012908Z） |
|
| 摘要点击次数: 2006 |
| 全文下载次数: 2371 |
| 中文摘要: |
| 基于固化稳定法（S/S）在重金属污染场地处理方面的技术和研究，将硝酸镉（Cd2+）掺入土体模拟污染土，根据正交试验设计掺入不同含量水泥、粉煤灰、石灰组成的固化剂，压实成型后分别养护7、28、60、90 d，通过测定无侧限抗压强度、淋滤浸出重金属浓度和固化孔隙范围比例，探讨不同镉离子浓度、固化掺量配比和养护龄期对其影响。试验结果表明：随着固化剂掺量和养护龄期的增加，其无侧限抗压强度显著增强，重金属浸出率降低，趋于稳定；水泥对无侧限抗压强度影响显著性最大，水泥-粉煤灰-石灰掺量为8%-6%-6%时对抗压强度较为有利；28 d固化土其孔径主要分布于0.01~1 μm，结构致密；10 μm以上孔隙比例增加，导致强度降低，淋滤浸出浓度偏高，不利于固化水化产物填充。 |
| 英文摘要: |
| The Stabilization and Solidification(S/S) method is one of the common methods currently applied in treatment of heavy metal contaminated sites. Application of S/S will not only improve the strength of the contaminated soil but also stabilize and solidify the heavy metal ions in the soil so that the same can be reused as fillings for shallow roadbed or foundation. Based on S/S-related technology and research, we added cadmium nitrate(Cd2+) into the soil to simulate the contaminated soil, and then, according to the design of the orthogonal test, the soil was mixed with curing agent composed of cement, fly ash, lime, each in different amounts, and then put under compaction molding for 7 d, 28 d, 60 d, 90 d. By studying the unconfined compressive strength, concentration of trickle-leaching heavy metals and the range and proportion of post-curing pore sizes, this paper explores how different cadmium ion concentration, mixing amount/ratio of curing agent and curing age affect the soil tested. The test results showed that with the increase of curing agent dosage and curing age, unconfined strength of the soil was significantly enhanced while heavy metal leaching rate were decreasing to a more stable state; the most influential factor on curing strength is cement content; best curing strength can be achieved with the mixing ratio of 8%(cement), 6%(fly ash), 6%(lime); in the case of 28 d solidification, the pore sizes were mainly in the range of 0.01~1 μm, indicating compact soil structure; higher proportion of pores over 10 μm in diameter will result in lower strength and higher concentration of trickle-leaching heavy metals, both of which are not conducive to using curing-hydration products for filling purposes. |
| HTML
查看全文
查看/发表评论 下载PDF阅读器 |
|
|
|
