改性活性炭吸附饮用水中三氯硝基甲烷的研究

为提高活性炭对三氯硝基甲烷(TCNM)的去除效率,采用NaOH对颗粒活性炭(GAC)进行改性.分别采用比表面积孔径分布测定仪、扫描电镜、傅里叶红外变换光谱等仪器及Boehm官能团滴定法,对改性前后活性炭的表面理化性质进行表征.并在不同反应条件下,考察活性炭改性前后吸附饮用水中TCNM的效果.结果表明:对于10μg/L的TCNM溶液,吸附剂投加量为0.3g/L时,NaOH-GAC的吸附去除率为87%,是GAC的1.71倍.吸附剂对TCNM的吸附过程大致分为快速阶段、慢速阶段和动态平衡阶段.GAC吸附TCNM溶液的吸附平衡时间为36h, NaOH-GAC吸附TCNM溶液的吸附平衡时间为6h.GAC和NaOH-GAC吸附TCNM的快速吸附阶段均符合一级反应动力学规律.

Adsorption of trichloronitromethane in drinking water by modified activated carbon

In order to enhance the adsorption efficiency of trichloronitromethane (TCNM) by activated carbon, the modification method of granular activated carbon (GAC) by sodium hydroxide solution was applied. The surface physical and chemical properties of GAC before and after modification were investigated by specific surface porosity detector, scanning electron microscope, Fourier transform infrared spectrometry and Boehm functional group titration method, respectively. In addition, the performance of TCNM adsorption by common GAC and modified activated carbon (NaOH-GAC) were also observed under different reaction conditions. It was shown that when the initial concentration of TCNM was 10μg/L, 87% removal was achieved by using NaOH-GAC with the addition of 0.3g/L, which was 1.71 times higher than that by common GAC. The TCNM adsorption process by GAC and NaOH-GAC could be described as three phases, which were rapid phase, slow phase and dynamic equilibrium phase, in which the equilibrium time of TCNM adsorption by GAC was 36 hours, while the time by NaOH-GAC was reduced to 6 hours. The TCNM rapid adsorption processes by GAC and NaOH-GAC were fitted with the first-order reaction kinetics model.