铁基竹子生物质炭复合材料的制备及其对水中三氯甲烷的去除研究

Preparation of iron-based bamboo biochar and adsorption fortrichloromethane in aqueous environment

为探索高效利用生物质资源制备生物炭去除水体中的消毒副产物,本研究以竹子为原料在400℃下热解制备生物炭,然后采用FeCl_(3)/FeSO_(4)共沉淀法对生物炭进行表面改性,得到铁基竹子生物炭复合材料(MBC),并针对其吸附水中三氯甲烷的作用开展了一系列研究。探究不同条件如温度、反应时间、三氯甲烷初始浓度、MBC投加量、pH对吸附量的影响。表征结果表明,改性后的生物炭具有磁性特征,有利于其回收利用。批量吸附实验研究表明,铁基竹子生物炭复合材料(MBC)对三氯甲烷的吸附量可达558μg·g^(-1)。酸性条件及高温环境有利于吸附过程。吸附过程符合准二级动力学模型,且反应为吸热过程,熵增且自发进行。Langmuir与Freundlich吸附等温模型均能很好地拟合吸附过程。本研究所制备的复合材料对水环境中三氯甲烷的去除具有明显效果,且易于回收利用。

In order to make full use of biomass resources to remove the disinfection by-products in aqueous environment,this study used bamboo as the raw materials to prepare the biochar by pyrolysis under 400℃,and then used FeCl_(3)/FeSO_(4) co-precipitation to modify the surface of bamboo biochar to obtain the biochar composite material MBC.Meanwhile,factors effecting adsorption capacity of MBC on trichloromethane were explored,including temperature,reaction time,the initial concentrations of trichloromethane,dosage of MBC and the value of pH.The results indicated that the modified biochar had magnetic characteristics,which enabled it good recycle prospect from the aqueous environment.The batch adsorption experimental results showed that the adsorption capacity of MBC in aqueous environment reached to 558μg/g trichloromethane.And the acid and high temperature environment is beneficial to the adsorption process.The adsorption kinetics and adsorption thermodynamics studies showed that adsorption process of trichloromethane in aqueous environment by Iron-based bamboo biochar accorded with quasi-secondary kinetic model and the reaction process adsorbed heat,the entropy increased and the process went spontaneously.The Langmuir and Freundlich adsorption isotherm model can both fitted the adsorption process.The MBC prepared in this study has a good effect on removal of trichloromethane in aqueous environment and is easy to be recycled.