Removal Of Typical Perfluorine Compounds In Water By Physical Adsorption Combinted With Sulfite/UV Reduction

Perfluorinated compounds(PFCs)with the high chemical stability,thermal stability,hydrophobic properties to water and oil,are widely used in the living and industrial production.In recent years,PFCs were detected in varied environments,animals and human beings,which attracted wide attention due to their biological toxicity,bioaccumulation,high durability and other potential toxicity.It has been reported that simple biochemical methods were difficult to degrade PFCs.Adsorption methods have a certain enrichment capability in low-concentration PFCs,however,this method can not remove them indeed.On the other hand,photochemical technologies could degrade PFCs to some extent,but this process consumed high energy during low-concentration PFCs' treatment.This study employed a combined process involved adsorption and sulfite/UV reduction to treat six typical PFCs with different C-F chains and functional groups.The adsorption properties of PFCs in water on the boehmite and activated carbon were studied.Moreover,the degradation process of these six PFCs were also evaluated by sulfite/UV reduction method.As respect to adsorption method,The study found that the adsorption effect of traditional adsorption materials on six kinds of PFCs is better than that of natural mineral materials.The adsorption of six PFCs on the two materials increased with the increase of C-F chain.Boehmite adsorbed these six PFCs mainly in the term of single-layer adsorption,while PAC adsorbed these six PFCs mainly in the term of multi-layer adsorption.The adsorption processes of boehmite and activated carbon were significantly affected by p H,and a low p H was favorable for adsorption.The co-existed calcium ions,magnesium ions,humic acid and surfactants all affected the adsorption of PFCs.PFCs.Desorption experiments for optimizing the activated carbon,studies have shown that six kinds of PFCs can obtain good effect of stripping,desorption rate is above 80%.PFCs can be enriched through the adsorption-desorption,and activated carbon has good usability cycles.The experimental results showed that when the initial concentration of six PFCs was 5 mg/L,the degradation rate of PFOA was highest in the same reaction conditions,which could reach over 99%.The study also showed that short-chain fluorocarbons have lower degradation rates than long-chain fluorocarbons.At the same time,the degradation rate of the six PFCs decreased with different levels of calcium,chloride and humic acid...