超滤处理东江水不可逆膜污染物的识别和活性炭对其吸附去除

利用超滤实验以及6种粉末活性炭吸附东江水有机物的水质数据,通过三维荧光光谱-平行因子分析(EEMPARAFAC),考察东江水中造成不可逆膜污染的主要组分和活性炭吸附这些组分的效果;随后进行活性炭对不可逆膜污染组分吸附效果与对应活性炭孔结构参数的相关性分析,揭示活性炭的表面物理性质对不可逆膜污染物吸附的影响.EEMPARAFAC模型识别出东江水含有2个类腐殖质荧光组分C1和C3,以及1个类蛋白质(类色氨酸)荧光组分C2,其中C2为主要不可逆膜污染物.同时,所有活性炭对3种荧光组分均有较好的吸附效果,其中对主要膜污染物C2的去除率可达54.0%~74.6%.相关性分析发现,活性炭对主要膜污染荧光组分C2吸附效果受活性炭微孔表面积的影响,而活性炭对两种次要膜污染荧光组分C1和C3吸附效果受活性炭中大孔表面积和BET比表面积影响.实验结果可为活性炭-超滤工艺处理东江水的活性炭选型提供技术指导.

Identification and PAC Adsorption of Foulants Responsible for Irreversible Fouling During Ultrafiltration of Dongjiang River Water

Foulants responsible for hydraulic irreversible fouling in Dongjiang River water were identified by ultrafiltration process and their removal by powdered activated carbon (PAC) adsorption treatment was investigated using fluorescent excitation emission matrix and parallel factor analysis (EEM-PARAFAC). A correlation analysis was then carried out for samples between the maximum fluorescence intensities (F_max) of three PARAFAC components after PAC adsorption and the surface properties of corresponding PAC samples. The results showed that two humic-like (C1 and C3) and one tryptophan-like fluorescent components were obtained through PARAFAC analysis, in which tryptophan-like component C2 was found to be the main substance in hydraulic irreversible foulants extracted from fouled membrane. Furthermore, the results of correlation analysis suggested that microspore area of PAC correlated with PAC adsorption of tryptophan-like fluorescent components, which played an important role in irreversible fouling. Both BET and mesopore+macropore area of PAC correlated with its adsorption of humic-like fluorescent components. The result provided support for selecting PAC in PAC-ultrafiltration hybrid process, which would be more effective for fouling control.