| Autor: |
Zhao H; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China.; Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Ministry of Agriculture/Tianjin Key Laboratory of Agro-environment and Safe-product, Tianjin, 300191, China., Huang X; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China., Zhang G; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China., Li J; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China., He Z; Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL, 34945, USA., Ji P; College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, China. jipuhui1983@163.com.; Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, Liaoning, China. jipuhui1983@163.com., Zhao J; Shenzhen ImMidas Environmental Technology Co., Ltd, Room 210, Chuangke Compound, 1018# Chaguang Road, Nanshan District, Shenzhen, 518000, China. |
| Abstrakt: |
Coal fly ash (FA) is a solid waste produced in coal combustion. This study focused on the removal of Cd 2+ from wastewater by a newly synthesized adsorbent material, the low-temperature and sodium hydroxide-modified fly ash (SHM-FA). The SEM and BET analyses of SHM-FA demonstrated that the adsorbent was porous and had a huge specific surface area. The XRF, XRD, FTIR and TGA characterization showed that SHM-FA has an amorphous structure and the Si-O and Al-O in the fly ash dissolved into the solution, which improved the adsorption capacity of Cd. The results indicated that SHM-FA has desired adsorption performance. The adsorption performance was significantly affected by the dosage, starting pH, Cd 2+ initial concentrations, and temperature, as well as adsorption time. In the optimal conditions, the removal efficiency and adsorption capacity of Cd 2+ by SHM-FA were 95.76% and 31.79 mg g -1 , respectively. The experiment provided clearly explained adsorption kinetics and isotherms. And the results confirmed that the adsorption behavior was well described by the pseudo-second-order kinetic and Langmuir isotherm model, which means that the adsorption of Cd 2+ was controlled by SHM-FA through surface reaction and external diffusion process. In addition, the recycling of SHM-FA for reuse after Cd 2+ adsorption showed high removal efficiency up to six times of use. Therefore, it can be concluded that SHM-FA is a low-cost adsorbent for Cd 2+ removal from wastewater. |
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