Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials
To explore the strength change law and solidification mechanism of cement solidified heavy metal lead and chromium contaminated soil, ordinary Portland cement (OPC) and magnesium phosphate cement (MPC) were used for solidification/stabilization treatment. Through the unconfined compressive strength...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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EDP Sciences
2023-01-01
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| Series: | MATEC Web of Conferences |
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| Online Access: | https://www.matec-conferences.org/articles/matecconf/pdf/2023/09/matecconf_amme2023_01008.pdf |
| _version_ | 1797775687670562816 |
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| author | Zheng Chao Xiong Kangwei Yang Kun Feng Deluan |
| author_facet | Zheng Chao Xiong Kangwei Yang Kun Feng Deluan |
| author_sort | Zheng Chao |
| collection | DOAJ |
| description | To explore the strength change law and solidification mechanism of cement solidified heavy metal lead and chromium contaminated soil, ordinary Portland cement (OPC) and magnesium phosphate cement (MPC) were used for solidification/stabilization treatment. Through the unconfined compressive strength (UCS) test, scanning electron microscopy (SEM) and the leaching toxicity test, the microscopic characteristics of the cement type, the cement content, the ion type, the ion concentration, and the age and their influence law on the strength characteristics of heavy metal contaminated soil were obtained. The UCS test shows that the compressive strength increases with the cement content and age. When OPC and MPC were used to solidify lead and chromium heavy metal contaminated soil, the compressive strength of OPC was greater than that of MPC, and when the curing age was 28 days, 20% of OPC and MPC satisfied the landfill requirements. The leaching toxicity test showed that after the solidification/stabilization of heavy metal lead and chromium contaminated soil by OPC and MPC, the leaching content of lead ions in the leaching solution conforms to the national limit. For chromium contaminated soil, the concentration was less than or equal to 5000mg/kg, which conform to the limit standard. When the concentration was 10000mg/kg, the content exceeded the limit. Therefore, heavy metal lead contaminated soil is more easily stabilized than chromium contaminated soil. Microscopic tests show that OPC solidified heavy metal contaminated soil is solidified/stabilized by heavy metal ions through hydration products, namely, ettringite and amorphous cementing materials. MPC is obtained by the hydration reaction of magnesium oxide and ammonium dihydrogen phosphate to form struvite, and heavy metal ions are encapsulated in the lattice to achieve solidification/stabilization. |
| first_indexed | 2024-03-12T22:39:12Z |
| format | Article |
| id | doaj.art-3ee88c0771a04e1aa4a524303d836156 |
| institution | Directory Open Access Journal |
| issn | 2261-236X |
| language | English |
| last_indexed | 2024-03-12T22:39:12Z |
| publishDate | 2023-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | MATEC Web of Conferences |
| spelling | doaj.art-3ee88c0771a04e1aa4a524303d8361562023-07-21T09:55:58ZengEDP SciencesMATEC Web of Conferences2261-236X2023-01-013820100810.1051/matecconf/202338201008matecconf_amme2023_01008Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materialsZheng Chao0Xiong Kangwei1Yang Kun2Feng Deluan3Guangzhou Grandtop Environment Service Co., Ltd.Guangzhou Grandtop Environment Service Co., Ltd.Guangzhou Grandtop Environment Service Co., Ltd.School of Civil and Transportation Engineering, Guangdong University of TechnologyTo explore the strength change law and solidification mechanism of cement solidified heavy metal lead and chromium contaminated soil, ordinary Portland cement (OPC) and magnesium phosphate cement (MPC) were used for solidification/stabilization treatment. Through the unconfined compressive strength (UCS) test, scanning electron microscopy (SEM) and the leaching toxicity test, the microscopic characteristics of the cement type, the cement content, the ion type, the ion concentration, and the age and their influence law on the strength characteristics of heavy metal contaminated soil were obtained. The UCS test shows that the compressive strength increases with the cement content and age. When OPC and MPC were used to solidify lead and chromium heavy metal contaminated soil, the compressive strength of OPC was greater than that of MPC, and when the curing age was 28 days, 20% of OPC and MPC satisfied the landfill requirements. The leaching toxicity test showed that after the solidification/stabilization of heavy metal lead and chromium contaminated soil by OPC and MPC, the leaching content of lead ions in the leaching solution conforms to the national limit. For chromium contaminated soil, the concentration was less than or equal to 5000mg/kg, which conform to the limit standard. When the concentration was 10000mg/kg, the content exceeded the limit. Therefore, heavy metal lead contaminated soil is more easily stabilized than chromium contaminated soil. Microscopic tests show that OPC solidified heavy metal contaminated soil is solidified/stabilized by heavy metal ions through hydration products, namely, ettringite and amorphous cementing materials. MPC is obtained by the hydration reaction of magnesium oxide and ammonium dihydrogen phosphate to form struvite, and heavy metal ions are encapsulated in the lattice to achieve solidification/stabilization.https://www.matec-conferences.org/articles/matecconf/pdf/2023/09/matecconf_amme2023_01008.pdfheavy metalnormal portland cementmagnesium phosphate cementsolidification/stabilizationleaching toxicity |
| spellingShingle | Zheng Chao Xiong Kangwei Yang Kun Feng Deluan Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials MATEC Web of Conferences heavy metal normal portland cement magnesium phosphate cement solidification/stabilization leaching toxicity |
| title | Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials |
| title_full | Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials |
| title_fullStr | Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials |
| title_full_unstemmed | Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials |
| title_short | Experimental study on solidification/stabilization of heavy metal lead and chromium sludge solidified by cement-based materials |
| title_sort | experimental study on solidification stabilization of heavy metal lead and chromium sludge solidified by cement based materials |
| topic | heavy metal normal portland cement magnesium phosphate cement solidification/stabilization leaching toxicity |
| url | https://www.matec-conferences.org/articles/matecconf/pdf/2023/09/matecconf_amme2023_01008.pdf |
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