Van Huu Tap, Nguyen Lan Huong, Dang N V, Chao Huan-Ping, Nguyen Quang Trung, Nguyen Thu Huong, Nguyen Thi Bich Lien, Thanh Dang Van, Nguyen Hai Duy, Thang Phan Quang, Thanh Pham Thi Ha, Hoang Vinh Phu
Faculty of Natural Resources and Environment, TNU - University of Sciences (TNUS) Tan Thinh Ward Thai Nguyen City 24000 Vietnam
Faculty of Environment - Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry (HUFI) Ho Chi Minh City Vietnam.
RSC Adv. 2021 Feb 2;11(10):5801-5814. doi: 10.1039/d0ra09974k. eCollection 2021 Jan 28.
In this study, two types of agricultural wastes, sugarcane bagasse (SB) and cassava root husks (CRHs), were used to fabricate biochars. The pristine biochars derived from SB and CRHs (SBB and CRHB, respectively) were modified using ZnO nanoparticles to generate modified biochars (SBB-ZnO and CRHB-ZnO, respectively) for the removal of Reactive Red 24 (RR24) from stimulated wastewater. Batch experiments were performed to evaluate the effects of ZnO nanoparticles' loading ratio, solution pH, contact time, and initial RR24 concentration on the RR24 adsorption capacity of biochars. The RR24 adsorption isotherm and kinetic data on SBB, SBB-ZnO3, CRHB, and CRHB-ZnO3 were analyzed. Results indicate that SB- and CRH-derived biochars with a ZnO nanoparticle loading ratio of 3 wt% could generate maximum adsorption capacities of RR24 thanks to the double growth on the BET surface of modified biochars. The RR24 adsorption capacities of CRHB-ZnO3 and SBB-ZnO3 reached 81.04 and 105.24 mg g, respectively, which were much higher than those of pristine CRHB and SBB (66.19 and 76.14, respectively) at an initial RR24 concentration of 250 mg L, pH 3, and contact time of 60 min. The adsorption of RR24 onto biochars agreed well with the pseudo-first-order model and the Langmuir isotherm. The RR24 adsorption capacity on modified biochars, which were reused after five adsorption-desorption cycles showed no insignificant drop. The main adsorption mechanisms of RR24 onto biochars were controlled by electrostatic interactions between biochars' surface positively charged functional groups with azo dye anions, pore filling, hydrogen bonding formation, and π-π interaction.
在本研究中，使用了两种农业废弃物，甘蔗渣（SB）和木薯根壳（CRH）来制备生物炭。分别源自SB和CRH的原始生物炭（分别为SBB和CRHB）用氧化锌纳米颗粒进行改性，以生成改性生物炭（分别为SBB-ZnO和CRHB-ZnO），用于从模拟废水中去除活性红24（RR24）。进行了批量实验，以评估氧化锌纳米颗粒的负载率、溶液pH值、接触时间和初始RR24浓度对生物炭RR24吸附容量的影响。分析了SBB、SBB-ZnO3、CRHB和CRHB-ZnO3上的RR24吸附等温线和动力学数据。结果表明，由于改性生物炭BET表面的双重增长，负载率为3 wt%的源自SB和CRH的生物炭能够产生最大的RR24吸附容量。在初始RR24浓度为250 mg/L、pH值为3和接触时间为60分钟的条件下，CRHB-ZnO3和SBB-ZnO3的RR24吸附容量分别达到81.04和105.24 mg/g，远高于原始CRHB和SBB（分别为66.19和76.14）。RR24在生物炭上的吸附与准一级模型和朗缪尔等温线吻合良好。经过五个吸附-解吸循环后重复使用的改性生物炭上的RR24吸附容量没有显著下降。RR24在生物炭上的主要吸附机制受生物炭表面带正电的官能团与偶氮染料阴离子之间的静电相互作用、孔隙填充、氢键形成和π-π相互作用控制。
