生物基质活性炭对挥发性有机物的吸附

以咖啡渣和柚子皮生物基质为原料用磷酸活化法制成活性炭,探讨了制备条件对活性炭制备的影响,并研究了其对正丁烷的吸附行为。磷酸活化过程中磷酸的用量为生物基质质量的1.5倍为宜,咖啡渣采用超声干燥法,柚子皮采用水热法制备。制备的活性炭对正丁烷均有较好的吸附能力,以柚子皮为原料、磷酸用量为原料质量两倍活化制成的活性炭吸附性能最佳,最大吸附量约为商用活性炭的2倍。吸附剂均能较好地与兰格缪尔曲线相拟合,计算了不同正丁烷覆盖度下的等量吸附热,其变化规律与吸附曲线变化规律相一致。

Adsorption of VOCs using activated carbons prepared by biologic matters

Activated carbons were prepared by phosphoric acid activation using coffee grounds and pomelo skins as base materials. The best mass ratio of phosphoric acid to base materials is 3 to 2 during the preparation process. Coffee grounds were treated by ultrasonic and drying, while pomelo skins were activated by hydrothermal treatment. All the as-prepared adsorbents had good capacity for n-butane adsorption. The maximum adsorption amount of n-butane for the best adsorbent was almost twice as much the commercial activated carbon. All the isotherms fitted well with Langmuir model. The isosteric heats at different coverages were also calculated through Clausius-Clapeyron equation. They shared the same laws with the variation of n-butane adsorption isotherms.