|
| Adsorption performance of different substrates to combined sulfamethoxazole and hexavalent chromium pollution in a constructed wetland |
| Received:November 15, 2022 Revised:February 08, 2023 |
| View Full Text View/Add Comment Download reader |
| KeyWord:sulfamethoxazole;hexavalent chromium;combined pollution;substrate;adsorption;cluster analysis |
| Author Name | Affiliation | E-mail | | LI Guowan | College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Postdoctoral Workstation, Shenzhen BLY Landscape & Architecture Planning & Design Institute Ltd, Shenzhen 518055, China | | | HUANG Zhujian | College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China | | | LI Huashou | College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China | | | QIU Jianhe | Foshan YuHuang Ecology Environment Technology Co Ltd, Foshan 528200, China | | | CUI Lihua | College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China | lihcui@scau.edu.cn |
|
| Hits: 1232 |
| Download times: 646 |
| Abstract: |
| Environment Technology Co Ltd, Foshan 528200, China） Abstract： To discover which substrate types in a constructed wetland can synergistically adsorb sulfamethoxazole（SMZ）and hexavalent chromium [Cr（Ⅵ）], batch adsorption experiments were conducted using 10 substrates as adsorbents（vermiculite, zeolite, river sand, peat, paddy soil, blast furnace slag, diatomite, volcanic rock, K-feldspar, and gravel）. Adsorption kinetics, adsorption isotherms, and pH response changes of SMZ and Cr（Ⅵ）were studied in single and binary adsorption experiments. A Pseudo-second order model best described the adsorption process of SMZ and Cr（Ⅵ）on all substrates（R2≥0.993）, accompanied with three stages of intraparticle diffusion： volume diffusion, macroporous diffusion, and microporous diffusion（Ci >0）. SMZ and Cr（Ⅵ）interactively weakened volume diffusion and macroporous diffusion （P>0.05）. The adsorption amount of Cr （Ⅵ）decreased from 0.51-0.97 mg·g-1 to 0.48-0.49 mg·g-1, but the adsorption amount of SMZ increased from 0.35-0.54 mg·g-1 to 0.45-0.51 mg·g-1. The kinetics cluster of SMZ and Cr（Ⅵ）in paddy soil and volcanic rock changed more significantly. The Freundlich model well describes the adsorption behavior of SMZ and Cr（Ⅵ）on all substrates（R2≥ 0.839）. Cr（Ⅵ）mainly promoted SMZ adsorption, while SMZ affected Cr（Ⅵ）adsorption depending on the substrate type. Both SMZ and Cr（Ⅵ）mutually promoted adsorption by K-feldspar, blast furnace slag, volcanic rock, and gravel. The adsorption capacity of SMZ on Kfeldspar, blast furnace slag, volcanic rock, and gravel increased by 10%, 10%, 21%, and 25%, respectively. The adsorption capacity of Cr（Ⅵ）on K-feldspar, blast furnace slag, volcanic rock, and gravel increased by 166%, 71%, 104%, and 658% respectively. The isotherms cluster of SMZ and Cr（Ⅵ）in K-feldspar, blast furnace slag, volcanic rock, and gravel changed more significantly. When the pH increased, the adsorption amount of SMZ and Cr（Ⅵ）on each substrate decreased. The adsorption amounts of SMZ and Cr（Ⅵ）on peat and volcanic rock were higher than the others at an acidic pH. The pH response cluster of SMZ and Cr（Ⅵ）in peat and volcanic rock changed more significantly. Our results indicate that K-feldspar, blast furnace slag, volcanic rock, gravel, and peat are conducive to the synergistic adsorption of SMZ and Cr （Ⅵ）, and to the control combined of SMZ and Cr（Ⅵ）pollution by constructed wetlands. |
|
|
|
