College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, PR China.
College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou, Zhejiang 311300, PR China.
Bioresour Technol. 2023 Jul;379:129067. doi: 10.1016/j.biortech.2023.129067. Epub 2023 Apr 18.
Hydrochars are promising sorbents for wastewater treatment. Herein, two acrylate-modified hydrochars (AMHC and AMHC) were obtained by grafting acrylic acid on the surface of two hydrochars (MHC and MHC hydrothermally carbonized in water and acidic medium respectively) with free radical polymerization. Characterizations show that MHC is more prone to free radical polymerization than MHC does, and has higher carboxylate content after modification. The adsorption amounts of AMHC over methylene blue (MB) and Pb(II) are much higher than those of AMHC. Pseudo-second-order kinetic and Langmuir isotherm equations well fit the Pb(II) and MB sorption data of AMHC. The Pb(II) adsorptive mechanism is mainly inner-surface complexation accompanied by ion exchange and cation-π interaction. MB adsorption involves ion exchange, electrostatic interaction, H-bonding and π-π interaction. Hence, the one-step modification method of free radical polymerization under alkaline condition has great potential for preparing carboxylate-modified hydrochars to adsorb cationic pollutants.
水凝胶碳是一种很有前途的废水处理吸附剂。本文通过自由基聚合，在两种水凝胶（分别在水相和酸性介质中热解得到的 MHC 和 MHC）表面接枝丙烯酸，制备了两种丙烯酸改性水凝胶碳（AMHC 和 AMHC）。表征结果表明，MHC 比 MHC 更易发生自由基聚合，且改性后羧酸盐含量更高。AMHC 对亚甲基蓝（MB）和 Pb(II)的吸附量均明显高于 AMHC。AMHC 对 Pb(II)和 MB 的吸附动力学数据可用准二级动力学方程和 Langmuir 等温吸附方程很好地拟合。Pb(II)的吸附机制主要是内表面络合，同时伴有离子交换和阳离子-π 相互作用。MB 的吸附涉及离子交换、静电相互作用、氢键和 π-π 相互作用。因此，碱性条件下自由基聚合的一步改性法在制备吸附阳离子污染物的羧酸盐改性水凝胶碳方面具有很大的潜力。
