Modeling adsorption kinetics of trichloroethylene onto biochars derived from soybean stover and peanut shell wastes

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102

作者：

M Ahmad，SL Sang，SE Oh，D Mohan，SO Yong

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摘要：

Trichloroethylene (TCE) is one of the most hazardous organic pollutants in groundwater. Biochar produced from agricultural waste materials could serve as a novel carbonaceous adsorbent for removing organic contaminants from aqueous media. Biochars derived from pyrolysis of soybean stover at 300 A degrees C and 700 A degrees C (S-300 and S-700, respectively), and peanut shells at 300 A degrees C and 700 A degrees C (P-300 and P-700, respectively) were utilized as carbonaceous adsorbents to study batch aqueous TCE remediation kinetics. Different rate-based and diffusion-based kinetic models were adopted to understand the TCE adsorption mechanism on biochars. With an equilibrium time of 8-10 h, up to 69 % TCE was removed from water. Biochars produced at 700 A degrees C were more effective than those produced at 300 A degrees C. The P-700 and S-700 had lower molar H/C and O/C versus P-300 and S-300 resulting in high aromaticity and low polarity accompanying with high surface area and high adsorption capacity. The pseudo-second order and intraparticle diffusion models were well fitted to the kinetic data, thereby, indicating that chemisorption and pore diffusion were the dominating mechanisms of TCE adsorption onto biochars.

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关键词：

SHOOTING RANGE SOIL ACTIVATED CARBON AQUEOUS-SOLUTION CONTAMINATED SOILS CR(VI) REDUCTION RAPESEED RESIDUE ZEROVALENT IRONS EGGSHELL WASTE