Removal Of Bisphenols In Different Process Sections Of Sewage Treatment Plant

Bisphenols are a kind of additives used in epoxy resins,vinyl resins,polycarbon resins,high-performance resin modifiers and flame retardants.Because of their good performance and low price,they are widely used in production and daily life.In the product.Studies have shown that bisphenols have endocrine disrupting effects and belong to Endocrine Disrupting Chemicals(EDCs).They have stable physical and chemical properties and can migrate long distances.They are distributed in environment-like media through the air and water cycles in nature.The accumulative effects and various toxicological effects of bisphenols on organisms in the environment have attracted wide attention from environmental scholars.At present,the production and use of some bisphenols have been restricted.Among all kinds of media,sewage is the most important medium for the existence and migration of bisphenols.The sewage collects various pollutants from production and life.Among them,the sewage in the city is collected to the sewage treatment plant through the municipal sewage pipe network,and the sewage is treated.The treatment of each treatment unit in the plant is discharged into the environmental medium after reaching the standard.The content of bisphenols in the effluent of the sewage treatment plant can reflect the pollution level and pollution status of the bisphenols in the water bodies in the area.Therefore,it is of great significance to study the removal of dual-classified substances in each treatment unit in a sewage treatment plant.The experiment studied the three most commonly used bisphenols—BPA(Bisphenol A),BPF(Bisphenol F)and BPS(Bisphenol S).The three substances were derivatized and detected by gas chromatography-mass spectrometry.Method to determine,and explore the most suitable measurement conditions.Finally,it is determined to add 30?L of derivatization reagent,derivatize at 90?for 35min,and then conduct detection and quantitative analysis by gas chromatography and gas chromatography-pure.First,a standard curve was established with a linear range of 0.05-5 mg/L and a correlation coefficient greater than 0.999;after that,the pre-treatment optimization experiment was performed to determine the best extraction and purification conditions.The recovery rates of the three substances were all higher than 80%,relative to the standard The deviation is less than 8.04%;finally,the method is verified by the matrix addition recovery experiment.The average recovery rate of the three substances is82.9%?101.9%,and the relative standard deviation is 3.3%?10.1%.It can be seen that the determination of bisphenol in sewage The method for similar substances is reliable.In the experiment,sewage samples from each treatment unit in three sewage treatment plants with different treatment processes were collected,and the sewage samples were purified,enriched,eluted,concentrated,and derivatized.Then,gas chromatography and gas chromatography-mass spectrometry were used to analyze Three kinds of bisphenols in sewage are analyzed.The results show that these three bisphenol substances can be detected in the three sewage treatment plants,of which BPA is the dominant pollutant,and the proportion of the sewage in the three sewage treatment plants is higher than 55%.The total concentrations of BPA,BPF and BPS in the sewage of the three sewage treatment plants A,B and C ranged from 193.63-1656.79 ng/L,166.03-1305.26 ng/L,and 201.38-1214.77 ng/L,respectively.The removal rate of the three bisphenol substances in the three sewage treatment plants can reach more than 80%,the bisphenol content in the sludge is low,and the bisphenol content in the sludge of different process stages is not much different.Part of the biochemical treatment unit A~2/O plus post-hypoxic and post-aerobic processes have better treatment effects,but the oxidation ditch treatment effect is poor.The ultraviolet disinfection treatment effect of the advanced treatment part is the best,the treatment effect of the fiber biological turntable is the worst,and the removal rate of the remaining treatment units is relatively small.Overall,it can be seen that the removal effect of bisphenols by the sewage treatment plant is generally better.Finally,a risk assessment was carried out on the effluent of the three sewage treatment plants,and the results showed that the three substances in the discharge water of the three sewage treatment plants have no ecological risk to the algae,and there is no trend of low ecological risk;A sewage treatment plant BPA and BPF in the sewage discharge,BPA in the sewage discharge of B sewage treatment plant,BPA in the sewage discharge of C sewage treatment plant,has a low ecological risk to fish,and the rest has no fish Ecological risk.