姜黄渣/废橡胶混合热解炭材料及其对Cu2+的吸附

Preparation and adsorption of Cu2+ of a new biocarbon material derived by mixed pyrolysis of turmeric residue/waste rubber

摘要:

以80目的姜黄渣和废橡胶粉为原料，按照m(姜黄渣)∶m(废橡胶粉)＝2∶1混合热解制备姜黄渣-橡胶热解炭材料（TR-RPC），采用TGA、FTIR、XRD、SEM、BET和元素分析对TR-RPC进行表征，将其用于水溶液中Cu2+的吸附去除，考察吸附条件、阳离子共存对TR-RPC的Cu2+吸附性能的影响，采用吸附等温实验和动力学实验，探究其吸附机制。结果表明，姜黄渣和橡胶混合热解发生相互作用，其热解自由基与烃类结合形成稳定交联炭，两种原料中的二氧化硅促使TR-RPC形成高比表面积（92.38 m2/g）和大孔径（6.01 nm）结构，显著提高了其对Cu2?的吸附性能。在初始溶液pH=6、吸附温度30 ℃、吸附时间120 min的优化后TR-RPC吸附水溶液中Cu2+的条件下，投加量为0.1 g的TR-RPC对100 mL质量浓度150 mg/L的Cu2+的平衡吸附量为2.20 mmol/g，去除率为93%。Ca2+、Ni2+、Mg2+的加入对TR-RPC的Cu2+平衡吸附量和去除率影响较小，而Zn2+、Fe3+的影响较大。TR-RPC对Cu2+的吸附符合Freundlich等温吸附模型和准一级动力学模型，以多分子层的物理吸附为主，其吸附机制涉及配位作用和静电吸引。

Abstract:

Turmeric residue-rubber pyrolytic carbon (TR-RPC) was synthesized by co-pyrolysis of 80-mesh turmeric residue and waste rubber powder at a mass ratio of 2:1. The material was characterized by TGA, FTIR, XRD, SEM, BET, and elemental analysis. TR-RPC was applied for Cu2? removal from aqueous solutions, with a systematic investigation of adsorption conditions and the effects of coexisting cations on its adsorption performance. Adsorption isotherms and kinetic studies were conducted to elucidate the underlying mechanisms. The results indicated that co-pyrolysis of turmeric residue and rubber induced synergistic interactions, where pyrolytic free radicals combined with hydrocarbons to form stable cross-linked carbon structures. The inherent silica in both raw materials promoted the development of TR-RPC with a high specific surface area (92.38 m2/g) and large pore size (6.01 nm), which significantly enhanced its Cu2? adsorption performance. Under optimized conditions (initial pH = 6, temperature = 30 °C, contact time = 120 min), TR-RPC exhibited a high Cu2? adsorption capacity of 2.20 mmol/g and a removal efficiency of 93% for 100 mL of 150 mg/L Cu2? solution at a dosage of 0.1 g. The presence of coexisting cations (Ca2?, Ni2?, Mg2?) showed negligible effects on Cu2? adsorption, while Zn2? and Fe3? significantly interfered. The adsorption behavior followed the Freundlich isotherm and pseudo-first-order kinetics, indicating a multilayer physical adsorption mechanism dominated by coordination complexation and electrostatic attraction.