碳基材料对污水厂尾水和太湖水体中CDOM的吸附特征

Adsorption characteristics of carbon materials for CDOM in sewage plant outlet and waters of Taihu Lake

采用颗粒活性炭、粉末活性炭和碳纳米管3种典型碳基材料来吸附太湖水和污水厂尾水中的有机物,考察碳基材料对水中有色可溶性有机物(CDOM)的吸附特征。基于荧光光谱和平行因子分析(PARAFAC),提取出C1(腐殖酸类)、C2(色氨酸类蛋白)和C3(酪氨酸类蛋白)3个PARAFAC荧光组分。粉末活性炭和碳纳米管具有发达的中孔孔隙结构,对水中大分子有机物具有较高的吸附容量,颗粒活性炭微孔结构发达反而不利于吸附水中腐殖酸等大分子有机物。粉末活性炭对水中有机物具有最高的吸附速率,对太湖水中荧光组分C1、C2和C3的吸附速率分别为0.278、0.358和0.359min-1,颗粒活性炭的吸附速率明显低于粉末活性炭和碳纳米管。研究结果揭示了水中复杂混合有机物的吸附特征,为吸附工艺参数的优化提供技术参考。

Three typical carbon materials,including granular activated carbon( GAC),powdered activated carbon( PAC),and carbon nanotubes( CNTs),were used to adsorb and remove colored dissolved organic matter( CDOM) in waters of Taihu Lake and sewage plant outlet. The adsorption characteristics were also investigated.The combination of fluorescence spectrum and parallel factor( PARAFAC) analysis was carried out to extract three PARAFAC fluorescent components,including C1( humic-acid like),C2( tryptophan protein-like),and C3( tyrosine protein-like). PAC and CNTs have high adsorption capacity for large molecular organics with developed meso-porous structure. The micro-porous structure of GAC is not conducive to the adsorption of large molecular organics,such as humid acid. The adsorption rate of PAC was the largest with the adsorption rates of component C1,C2,C3 in Taihu Lake samples being 0. 278 and 0. 358,0. 359 min- 1,while the rate of GAC was much lower than that of PAC and CNTs. The research illustrated the adsorption characteristics of complex and mixed organic matter in waters,which might present the technical reference for the parameter optimization of adsorption technology.