Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China E-mail:
Water Sci Technol. 2021 May;83(10):2424-2436. doi: 10.2166/wst.2021.126.
Using solid adsorbents, such as biochar, has been a potential practice to remove the pollutants from water bodies to render the water safer for potential usage. A potential application of sludge biochar-based adsorbent (SBA), obtained by pyrolysis with hydrothermal treatment, was developed to adsorb Direct Red 23 (DR23) from wastewater. The results showed that for the synthesized SBA (0.5 g/L) in the adsorption of DR23 at low concentration (<20 mg/L), the DR23 was totally removed from the aqueous solution. pH had a limited effect on the adsorption, while an increase in temperature was shown to have a large enhancing effect. The adsorption kinetics were best fitted by the pseudo-second-order kinetic model, while the equilibrium data were best fitted by the Langmuir isotherm. A maximum saturation adsorption capacity of SBA of 111.98 mg/g was achieved. SBA could then be regenerated by pyrolysis, and after three cycles, SBA still retained good adsorption ability for DR23, a removal rate exceeding 97% was achieved. Functional groups, pores, π-π bond, and electrostatic interactions are the key to the adsorption mechanisms. The results proved that SBA would be a promising material in the application of removing dyes in printing and dyeing wastewater.
采用固体吸附剂，如生物炭，是一种从水体中去除污染物以提高水的潜在使用安全性的潜在方法。一种潜在的应用是利用水热热解制备的污泥生物炭基吸附剂（SBA）来吸附废水中的直接红 23（DR23）。结果表明，对于在低浓度（<20mg/L）下吸附 DR23 的合成 SBA（0.5g/L），DR23 可被完全从水溶液中去除。pH 对吸附的影响有限，而温度升高则表现出较大的增强作用。吸附动力学最符合准二级动力学模型，而平衡数据最符合朗缪尔等温线。SBA 的最大饱和吸附容量为 111.98mg/g。SBA 可以通过热解再生，经过三次循环后，SBA 对 DR23 仍保持良好的吸附能力，去除率超过 97%。官能团、孔隙、π-π 键和静电相互作用是吸附机制的关键。结果证明 SBA 有望在去除印染废水中染料的应用中得到应用。
