Wei Xinxing, Zhang Renjing, Zhang Wenchao, Yuan Yue, Lai Bo
State Key Laboratory of Hydraulics and Mountain River Engineering, College of Architecture and Environment, Sichuan University Chengdu 610065 China
Sino-German Centre for Water and Health Research, Sichuan University Chengdu 610065 China.
RSC Adv. 2019 Nov 29;9(67):39355-39366. doi: 10.1039/c9ra07289f. eCollection 2019 Nov 27.
Porous biochar (PBC) derived from Cr-containing waste collagen fibers was prepared by two-step pyrolysis to 800 °C (PBC-800) and alkali activation. Brunauer-Emmet-Teller (BET) analysis, scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), thermogravimetric analysis (TGA) and zeta potential analysis were used to characterize PBC-800. Batch experiments showed that PBC-800 had an excellent removal effect on tetracycline (TC), and the maximum adsorption capacity was 593.84 mg g. Meanwhile, PBC-800 was found to be suitable for a wide pH range. The isothermal adsorption and kinetic model fitting proved that the TC adsorption by PBC-800 occurred 5 types of chemical adsorption. The main rate-limiting step was closely related to the initial concentration of TC. The total release of Cr was less than 0.05 mg L, which indicated that PBC-800 was stable and did not cause serious secondary pollution. Compared to the conventional metal-free biomass, Cr in a waste collagen fiber (WCF) played an important role in carbon formation and adsorption. The excellent adsorption properties of PBC-800 indicated that it could enrich low concentrations of TC in water. Thus, WCF can be used to prepare cost-effective PBC, which supplies a new process to reuse Cr-containing waste.
通过两步热解至800°C（PBC - 800）和碱活化制备了源自含铬废胶原纤维的多孔生物炭（PBC）。采用布鲁诺尔-埃米特-泰勒（BET）分析、扫描电子显微镜（SEM）、拉曼光谱、X射线光电子能谱（XPS）、傅里叶变换红外光谱（FTIR）、X射线荧光（XRF）、热重分析（TGA）和zeta电位分析对PBC - 800进行表征。批量实验表明，PBC - 800对四环素（TC）具有优异的去除效果，最大吸附容量为593.84 mg/g。同时，发现PBC - 800适用于较宽的pH范围。等温吸附和动力学模型拟合证明，PBC - 800对TC的吸附发生了5种化学吸附类型。主要限速步骤与TC的初始浓度密切相关。Cr的总释放量小于0.05 mg/L，这表明PBC - 800是稳定的，不会造成严重的二次污染。与传统的无金属生物质相比，废胶原纤维（WCF）中的Cr在碳形成和吸附中起重要作用。PBC - 800优异的吸附性能表明它可以富集水中低浓度的TC。因此，WCF可用于制备具有成本效益的PBC，为含铬废物的再利用提供了一种新方法。
