Preparation Of Nylon 6 Nanofiber Membrane And Its Application For The Rapid Detection Of Polycyclic Aromatic Hydrocarbons In Water

Polycyclic aromatic hydrocarbons (PAHs) are one kind of persistent organic pollutants which are widely distributed in the environment and easily accumulated in organisms, show strong carcinogenic, teratogenic and mutagenic effects. Most of the conventional analysis methods for PAHs are time-consuming, high-cost and need complicated pretreatment, which are difficult to meet the needs of rapid detection for a large number of samples. Therefore, it is urgent to develop a simple, rapid and accurate method for the determination of PAHs.Nylon 6 nanofiber membrane was prepared with self-made electrostatic spinning device in the lab. The influence of nylon 6 spinning solution concentration and spinning conditions (spinning voltage, spinning distance and flow rate) on the diameter and morphology of nanofibers were studied with scanning electron microscope. Through the calculation of the nanofiber diameter and the observation of nanofiber morphology, the optimal spinning condition was chosen as follow:spinning solution concentration is 0.25g/ml, spinning voltage is 17kv, spinning distance is 17cm, spinning flow is 0.20ml/h.With natural absorption and suction filtration absorption, nanofiber membrane was used to absorb PAHs in water. The adsorption characteristics of nanofiber membrane for phenanthrene, pyrene, fluoranthene in water were studied, by analyzing the changing of membrane adsorption capacity (Q) with the time of adsorption(t) and the concentration of PAHs in water(c).The results show:Nylon 6 nanofiber membrane has strong adsorption capacity for phenanthrene, pyrene, fluoranthene, and the adsorption process followed the pseudo second-order kinetic model, both under the natural adsorption and the suction filter. The membrane adsorption quantity(Q) and the concentration of PAHs in water show a good linear relationship, the enrichment coefficient of phenanthrene, pyrene, fluoranthene under the suction filter is 3.91,9.88,9.02 times of that under natural adsorption. Therefore, the efficiency of suction filtration adsorption is obviously better than that of the natural absorption, which is more suitable to be used in film detection for PAHs.Based on the excellent adsorption capacity of nylon 6 nanofiber membrane to PAHs in water, the method of membrane enrichment/solid phase surface fluorescence spectrometry for trace PAHs in water was established. The experimental results show that:The detection limits of the method for the determination of phenanthrene, pyrene, fluoranthene were 9.73×10-4μg/ml, 1.62×10-5μg/ml,8.96×10-4μg/ml, the average recoveries for tap water were 87.2%～98.2%, 100.76%～120%,85.75%～92.32%,the relative standard deviations were 7.0%,2.63%,5.1%.