Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer
Red-mud leachate from tailings ponds contains Cr(VI), which can pollute groundwater via infiltration through anti-seepage layers. This paper investigates leachate from a red-mud tailings pond in southwest China and the red clay in the surrounding area to simulate the adsorption of Cr(VI) onto clay a...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-10-01
|
| Series: | Toxics |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2305-6304/10/10/606 |
| _version_ | 1827647868070002688 |
|---|---|
| author | Yibo Zhang Yue Yu Hao Qin Daoping Peng Xing Chen |
| author_facet | Yibo Zhang Yue Yu Hao Qin Daoping Peng Xing Chen |
| author_sort | Yibo Zhang |
| collection | DOAJ |
| description | Red-mud leachate from tailings ponds contains Cr(VI), which can pollute groundwater via infiltration through anti-seepage layers. This paper investigates leachate from a red-mud tailings pond in southwest China and the red clay in the surrounding area to simulate the adsorption of Cr(VI) onto clay at different pHs, using geochemical equilibrium software (Visual MINTEQ). We also performed dynamic adsorption testing of Cr(VI) on a clay anti-seepage layer. The dynamic adsorption behaviors and patterns in the dynamic column were predicted using the Thomas and Yoon–Nelson models. Visual MINTEQ predicted that Cr(VI) adsorption in red-mud leachate onto clay was 69.91%, increasing gradually with pH, i.e., adsorption increased under alkaline conditions. Cr(VI) concentration in the effluent was measured using the permeability test through a flexible permeameter when the adsorption saturation time reached 146 days. At a low seepage rate, Cr(VI) adsorption onto the clay anti-seepage layer took longer. Saturation adsorption capacity, <i>q</i><sub>0</sub>, and adsorption rate constant, <i>K<sub>th</sub></i>, were determined using the Thomas model; the Yoon–Nelson model was used to determine when the effluent Cr(VI) concentration reached 50% of the initial concentration. The results provide parameters for the design and pollution prediction of the clay anti-seepage layer of red-mud tailings ponds. |
| first_indexed | 2024-03-09T19:25:34Z |
| format | Article |
| id | doaj.art-1b0e243e5abb4bb2b670f8578b50dd0e |
| institution | Directory Open Access Journal |
| issn | 2305-6304 |
| language | English |
| last_indexed | 2024-03-09T19:25:34Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxics |
| spelling | doaj.art-1b0e243e5abb4bb2b670f8578b50dd0e2023-11-24T02:57:54ZengMDPI AGToxics2305-63042022-10-01101060610.3390/toxics10100606Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage LayerYibo Zhang0Yue Yu1Hao Qin2Daoping Peng3Xing Chen4School of Emergency Management, Xihua University, Chengdu 610039, ChinaSchool of Emergency Management, Xihua University, Chengdu 610039, ChinaSchool of Emergency Management, Xihua University, Chengdu 610039, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaRed-mud leachate from tailings ponds contains Cr(VI), which can pollute groundwater via infiltration through anti-seepage layers. This paper investigates leachate from a red-mud tailings pond in southwest China and the red clay in the surrounding area to simulate the adsorption of Cr(VI) onto clay at different pHs, using geochemical equilibrium software (Visual MINTEQ). We also performed dynamic adsorption testing of Cr(VI) on a clay anti-seepage layer. The dynamic adsorption behaviors and patterns in the dynamic column were predicted using the Thomas and Yoon–Nelson models. Visual MINTEQ predicted that Cr(VI) adsorption in red-mud leachate onto clay was 69.91%, increasing gradually with pH, i.e., adsorption increased under alkaline conditions. Cr(VI) concentration in the effluent was measured using the permeability test through a flexible permeameter when the adsorption saturation time reached 146 days. At a low seepage rate, Cr(VI) adsorption onto the clay anti-seepage layer took longer. Saturation adsorption capacity, <i>q</i><sub>0</sub>, and adsorption rate constant, <i>K<sub>th</sub></i>, were determined using the Thomas model; the Yoon–Nelson model was used to determine when the effluent Cr(VI) concentration reached 50% of the initial concentration. The results provide parameters for the design and pollution prediction of the clay anti-seepage layer of red-mud tailings ponds.https://www.mdpi.com/2305-6304/10/10/606clay anti-seepage layerred-mud leachateCr(VI)Visual MINTEQ simulationdynamic adsorption |
| spellingShingle | Yibo Zhang Yue Yu Hao Qin Daoping Peng Xing Chen Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer Toxics clay anti-seepage layer red-mud leachate Cr(VI) Visual MINTEQ simulation dynamic adsorption |
| title | Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer |
| title_full | Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer |
| title_fullStr | Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer |
| title_full_unstemmed | Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer |
| title_short | Dynamic Adsorption Characteristics of Cr(VI) in Red-Mud Leachate onto a Red Clay Anti-Seepage Layer |
| title_sort | dynamic adsorption characteristics of cr vi in red mud leachate onto a red clay anti seepage layer |
| topic | clay anti-seepage layer red-mud leachate Cr(VI) Visual MINTEQ simulation dynamic adsorption |
| url | https://www.mdpi.com/2305-6304/10/10/606 |
| work_keys_str_mv | AT yibozhang dynamicadsorptioncharacteristicsofcrviinredmudleachateontoaredclayantiseepagelayer AT yueyu dynamicadsorptioncharacteristicsofcrviinredmudleachateontoaredclayantiseepagelayer AT haoqin dynamicadsorptioncharacteristicsofcrviinredmudleachateontoaredclayantiseepagelayer AT daopingpeng dynamicadsorptioncharacteristicsofcrviinredmudleachateontoaredclayantiseepagelayer AT xingchen dynamicadsorptioncharacteristicsofcrviinredmudleachateontoaredclayantiseepagelayer |