Chemical and Environmental Systems Modeling Research Group, National Institute of Fundamental Studies, Kandy, Sri Lanka.
Korea Biochar Research Center & Department of Biological Environment, Kangwon National University, Chuncheon, 200-701, Republic of Korea.
Environ Sci Pollut Res Int. 2017 Oct;24(29):22755-22763. doi: 10.1007/s11356-016-7430-6. Epub 2016 Aug 23.
Biochar has been considered as a potential sorbent for removal of frequently detected pesticides in water. In the present study, modified and non-modified rice husk biochars were used for aqueous carbofuran removal. Rice husk biochars were produced at 300, 500, and 700 °C in slow pyrolysis and further exposed to steam activation. Biochars were physicochemically characterized using proximate, ultimate, FTIR methods and used to examine equilibrium and dynamic adsorption of carbofuran. Increasing pyrolysis temperature led to a decrease of biochar yield and increase of porosity, surface area, and adsorption capacities which were further enhanced by steam activation. Carbofuran adsorption was pH-dependant, and the maximum (161 mg g) occurred in the vicinity of pH 5, on steam-activated biochar produced at 700 °C. Freundlich model best fitted the sorption equilibrium data. Both chemisorption and physisorption interactions on heterogeneous adsorbent surface may involve in carbofuran adsorption. Langmuir kinetics could be applied to describe carbofuran adsorption in a fixed bed. A higher carbofuran volume was treated in a column bed by a steam-activated biochar versus non-activated biochars. Overall, steam-activated rice husk biochar can be highlighted as a promising low-cost sustainable material for aqueous carbofuran removal.
生物炭已被认为是一种潜在的吸附剂，可用于去除水中经常检测到的农药。本研究使用改性和未改性稻壳生物炭去除水中的克百威。稻壳生物炭在 300、500 和 700°C 的慢速热解中产生，并进一步进行蒸汽活化。使用工业分析、元素分析、FTIR 方法对生物炭进行物理化学特性分析，并用于研究克百威的平衡和动态吸附。随着热解温度的升高，生物炭的产率降低，孔隙率、比表面积和吸附能力增加，蒸汽活化进一步提高了这些性能。克百威的吸附受 pH 值影响，在 pH 5 附近吸附量最大（161mg/g），采用 700°C 热解生成的蒸汽活化生物炭。Freundlich 模型最适合吸附平衡数据。在非均相吸附剂表面上，化学吸附和物理吸附相互作用都可能涉及克百威的吸附。Langmuir 动力学可用于描述固定床中克百威的吸附。与非活化生物炭相比，蒸汽活化生物炭在柱床中处理的克百威体积更高。总的来说，蒸汽活化稻壳生物炭可以作为一种有前途的低成本可持续的水相克百威去除材料。
