Department of Chemical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, 221005, India.
Department of Chemical Engineering and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, 221005, India.
Environ Res. 2022 Dec;215(Pt 2):114287. doi: 10.1016/j.envres.2022.114287. Epub 2022 Sep 8.
Peanut shell biomass was selected and utilized to produce biochar through pyrolysis under N atmosphere at 923 K. After studying various effects of experimental parameters and by statistical modeling and optimization by RSM using Box-Benken design, optimized conditions of pH 2.0 ± 0.1, temperature 303 K, and adsorbent dose used of 2.5 g L were obtained giving almost 99.99% removal for Cr(VI) from the solution. FESEM, FTIR, XRD, XPS, EDX, elemental mapping, and pH were used for the evaluation of the surface characteristics of peanut shell biochar (PSB). Studies revealed C-O, C-H, CO, and O-H functional groups' presence with the help of FTIR, majorly in control of adsorption mechanism and the EDX confirmed the presence of Cr(VI) onto peanut shell biochar (PSB). Further adsorption mechanism for Cr(VI) adsorption followed the pseudo-second-order rate with adsorption capacity of 29.38 mg g given by the Langmuir isotherm. The thermodynamic study confirmed the exothermic and spontaneous nature of the process for Cr(VI) adsorption onto PSB. The adsorption mechanism showed electrostatic attraction, reduction, and complexation mainly responsible for Cr(VI) adsorption by PSB. Thus, PSB effectively removes Cr(VI) is confirmed by the present study.
选择花生壳生物质，在 N 气氛下于 923 K 通过热解制备生物炭。通过研究各种实验参数的影响，并通过使用 Box-Benken 设计的 RSM 进行统计建模和优化，获得了优化条件为 pH 2.0±0.1、温度 303 K 和使用 2.5 g·L 的吸附剂剂量，使溶液中 Cr(VI)的去除率接近 99.99%。FESEM、FTIR、XRD、XPS、EDX、元素映射和 pH 用于评估花生壳生物炭（PSB）的表面特性。研究表明，FTIR 有助于存在 C-O、C-H、CO 和 O-H 官能团，主要控制吸附机制，EDX 证实了 Cr(VI)存在于花生壳生物炭（PSB）上。进一步的 Cr(VI)吸附机制遵循准二级速率，Langmuir 等温线给出的吸附容量为 29.38 mg·g。热力学研究证实了 Cr(VI)吸附到 PSB 上的过程是放热和自发的。吸附机制表明，静电吸引、还原和络合主要负责 PSB 对 Cr(VI)的吸附。因此，本研究证实了 PSB 能有效地去除 Cr(VI)。
