氧化镁负载的油茶壳基生物炭的制备及其吸附镉性能研究

重金属污染,尤其是废水中的镉污染,是环境和人类关注的重点,吸附是解决水体镉污染的有效手段。本文以油茶壳为碳源,氯化镁为活化剂,在500~700℃氮气气氛下制备了负载氧化镁的油茶壳基生物炭(MgO@AC-x,x为炭化温度),通过静态吸附实验研究了其对水中Cd^2+的最佳吸附条件。结果表明:室温下,pH为6时,初始Cd2+质量浓度为100mg·L^-1,吸附剂加入量为1g·L^-1,吸附时间为180min时,MgO@AC-500对Cd^2+的去除率98.78%。根据Langmuir热力学模型拟合,MgO@AC-500对Cd^2+的最大吸附量为913mg·g^-1。经6次循环后,MgO@AC-500对Cd^2+的吸附量下降了16.53%,生物炭具有良好的循环再生性能。该研究为农林废弃物资源化用于废水中重金属处理提供理论依据和技术支撑。

Cadmium removal from aqueous solution by Magnesium oxide embedded biochar composites

The pollution of heavy metals, especially cadmium in wastewater is a big concern for the environment andhumans, while adsorption is an effective approach to remove Cd from the water. In this study, MgO embedded biochar was prepared by the pyrolysis of Camellia oleifera shell after the impregnation of Magnesium chloride under a nitrogen atmosphere of 500 ~ 700 ℃, and the optimum adsorption conditions for Cd^2+ in water was studied by static adsorption experiments. The results showed that the removal rate of Cd^2+ by MgO@AC-500 was 98.78% within 180 min at pH value of 6 and the adsorption dosage of 1.0 g·L^-1 for initial Cd^2+ concentration of 100 mg·L^-1 . According to the Langmuir isothermal model fitting, the maximum adsorption capacity of MgO@AC-500 for Cd^2+ was 913 mg·g^-1 . The adsorption capacityto Cd^2+ decreased by 16.53% after 6 cycles, which showed that the biochar had good cycle regeneration performance. This study provided theoretical basis and technical support for the recycling of agricultural and forestry wastes for the treatment of heavy metals in wastewater.