一种新型烟秆吸附剂的制备与吸附Cr?机理研究

Preparation and Adsorption Mechanism for Cr(Ⅵ) of a New Sorbent from Tobacoo Stalk

以烟秆为原料,首次使用炭化法制备活性炭,并用于去除六价铬。以六价铬的去除率作为评价炭化温度,炭化时间,原料粒径的最佳炭化条件指标。采用激光颗粒分布测量仪、扫描电镜及傅里叶变换红外仪对该吸附剂进行表征。采用单批次振荡实验,探究了烟秆活性炭对六价铬的影响因素及机理。结果表明：在450℃,45 min,过100目筛子制备的烟秆活性炭对浓度为50 mg/L六价铬的去除率达到99.99%。烟秆活性炭颗粒直径主要集中在10-60μm间;其表面疏松且多孔;富含羟基（—OH）、烷烃、—C=C—、—C≡C—官能团。pH=1为吸附最佳条件,动力学研究表明吸附过程符合二级动力学,膜扩散步骤是烟秆活性炭去除六价铬的控制步骤。

A novel low-cost adsorbent,carbonized tobacoo stalk,as a solution to remove Cr（Ⅵ） ions from aqueous was reported. The Cr（Ⅵ） removal efficiency was took as an evaluating index for optimizing carbonized temperature,carbonized time and particle size of raw material. Laser Particle Size Distribution Measurement,Scanning Electron Microscope,FT-IR was use to character the adsorbent. Effects of various regulation parameters,such as p H value of reaction,adsorbent dosage and temperature was investigated. The results showed that the optimal adsorbent can be prepared under 450 ℃,45 min,less than 100 mesh,which can remove 50 mg / L Cr（Ⅵ） from aqueous solution by 99. 99%. The particle diameter is mainly between 10 - 60 μm,coarse and porous,surface functional group including（ —OH）,alkanes,—C= C—,—C ≡ C—. Kinetics studies indicated that the adsorption process could be well described by the pseudo-second-order equation. The membrane diffusion of water is the main control factor in the pellet diffusion.