Ai Tian, Jiang Xiaojun, Liu Qingyu, Lv Linlin, Dai Shujuan
School of Chemical Engineering, University of Science and Technology Liaoning Anshan 114051 PR China
College of Engineering, Shenyang Agricultural University Shenyang 110161 PR China.
RSC Adv. 2020 May 28;10(35):20427-20437. doi: 10.1039/d0ra02346a. eCollection 2020 May 27.
Single-component and competitive adsorption of tetracycline (TC) and Zn(ii) on an NHCl-induced magnetic ultra-fine buckwheat peel powder biochar (NHCl-BHP-char/FeO) was investigated in batch experiments. NHCl-BHP-char/FeO exhibited a large surface area of 1119.097 m g and a total pore volume of 0.139 cm g and was easily separated from aqueous solution using a magnet. Also, adsorption was endothermic, spontaneous, and highly pH-dependent. The optimum pH of the single-component adsorption of TC and Zn(ii) was 4.0 and 6.5, respectively, and the optimum pH of co-adsorption was 6.0. The kinetics studies showed the prepared biochar could be rapidly adsorbed within 60 min, and chemical adsorption was dominant. For single-component adsorption, the maximum adsorption capacities of TC and Zn(ii) were 106.38 and 151.52 mg g, respectively, and they underwent monolayer adsorption on the biochar surface. Moreover, for competitive adsorption, maximum TC and Zn(ii) adsorption capacities of 126.58 and 357.14 mg g were achieved. Both film diffusion and intra-particle diffusion were found to be significant processes to facilitate adsorption. TC and Zn(ii) promoted the adsorption of each other. The proposed biochar could be used repeatedly for at least four cycles. All these results demonstrated that developed NHCl-BHP-char/FeO was regarded as a low-cost alternative adsorbent to remove the heavy metal ions and antibiotic pollutants from water or wastewater.
通过批量实验研究了四环素（TC）和锌（II）在氯化铵诱导的磁性超细荞麦皮粉末生物炭（NHCl-BHP-char/Fe₃O₄）上的单组分和竞争性吸附。NHCl-BHP-char/Fe₃O₄具有1119.097 m²/g的大表面积和0.139 cm³/g的总孔体积，并且可以使用磁铁轻松地从水溶液中分离出来。此外，吸附是吸热的、自发的，并且高度依赖于pH值。TC和锌（II）单组分吸附的最佳pH值分别为4.0和6.5，共吸附的最佳pH值为6.0。动力学研究表明，制备的生物炭在60分钟内可以快速吸附，并且化学吸附占主导地位。对于单组分吸附，TC和锌（II）的最大吸附容量分别为106.38和151.52 mg/g，它们在生物炭表面进行单层吸附。此外，对于竞争性吸附，TC和锌（II）的最大吸附容量分别达到126.58和357.14 mg/g。发现膜扩散和颗粒内扩散都是促进吸附的重要过程。TC和锌（II）相互促进吸附。所提出的生物炭可以重复使用至少四个循环。所有这些结果表明，开发的NHCl-BHP-char/Fe₃O₄被认为是一种低成本的替代吸附剂，用于从水或废水中去除重金属离子和抗生素污染物。
