Application Of Quantitative Detection Of Pesticide Active Components In Pollutant Discharge Permit Technology

With the gradual deterioration of environmental problems and the development of current environmental protection situation,China has entered a critical period of reforming environmental management of stationary sources with the pollutant discharge permit system as the "core" system.In view of the key points of controlling the the full coverage of pollutant factors in the pollution discharge permit system,the quantitative detection of pesticide active ingredients,the comprehensive toxicity assessment of wastewater and the emission permit system were linked up for the first time.The current discharge situation was evaluated to determine whether the emission level meets the discharge requirements of the pollutant discharge permit.Therefore,a quantitative analysis method for nine pesticide active ingredients in industrial wastewater was established.The water samples were pretreated by three pretreatment methods: direct injection,liquid-liquid extraction and solid-phase extraction followed by rotary evaporation and concentration.The samples were detected by HPLC-MS-SIM mode.By comparing chromatographic conditions such as column length,mobile phase and collision-induced dissociation parameters,optimizing liquid-liquid extraction conditions such as solvent,volume of extractant,p H of water sample and Na Cl content,comparing solid-phase extraction conditions such as enrichment effect of C18solid-phase extraction column and HLB solid-phase extraction column,effect of eluent types and volume of eluent on elution efficiency,the most suitable three kinds of pretreatment methods were obtained.When direct injection was 10μL,the detection limit of the method was 12.51-16.53 μg/L and the recovery rate was 56.67%-96.17%.The detection limit of the liquid-liquid extraction method was 0.12-0.20 μg/L and the recovery rate was 75.58%-93.93%when the sample was 100 m L.The detection limit of the solid phase extraction method was0.08-0.23 μg/L and the recovery rate was 50.37%-92.30% when the sample was 100 m L.Sampling and testing the wastewater before and after sewage treatment units at all levels in three enterprises,the distribution level and removal rate of pesticide active ingredients were analyzed.The total removal rate of pesticide active ingredients in wastewater treatment processes of various enterprises was 69.21%-99.80%.It was found that the biochemical treatment system had a good removal effect on pesticide active ingredients,and the removal efficiency could reach 65.42%-99.91%.The concentration of pesticide active ingredients in the final effluent of three enterprises was low,ranging from 0.75 to 59.81 μg/L,which could meet the discharge requirements of pollutant discharge permit.The comprehensive toxicity tests of wastewater to Daphnia magna and zebrafish were also carried out by collecting waste water samples from the total outlets of three pesticide enterprises.The experimental results showed that two of the enterprises had a high degree of wastewater treatment,and the wastewater samples had little toxicity inhibition on Daphnia magna and zebrafish,which could meet the requirements of the follow-up discharge permit in China.The acute toxicity equivalent of the other enterprise to the two organisms could reach3.24 TUa and 4.24 TUa respectively,which were of high toxicity and belonged to grade III toxicity level.The result determined by dilution multiple method was that the acute toxicity of zebrafish exceeded the standard and could not meet the requirements of follow-up pollutant discharge permit.