Design Of A New Swirling Cavitation Device And Its Performance In The Treatment Of Wastewater Containing Trichlorfon

With the aggravation of agricultural non-point source pollution,the harm of groundwater and surface water pollution caused by organophosphorus pesticides to human beings can not be ignored.It is urgent to study low-cost and high-efficiency pesticide non-point source pollution control technology.Vortex cavitation technology is a new physicochemical water treatment technology with high efficiency,low cost and good water treatment effect.With the cavitation technology entering the cause of human beings,many studies show that this method has great potential in the treatment of sewage.Using cavitation technology to treat sewage can not only effectively remove many refractory and toxic substances,but also has the advantages of no secondary pollution and simple reaction device.Therefore,the adoption of this new water treatment technology is of great significance for improving water resources.In this study,a new type of eddy current cavitation device was designed,and the performance of trichlorfon,the most widely used organophosphorus pesticide in Guangdong Province,was studied by using the eddy current cavitation effect produced by the device.Finally,the performance of trichlorfon-containing wastewater degradation by eddy current cavitation effect was validated by treating actual trichlorfon-containing farmland drainage.The test results are as follows:(1)Combining with the domestic and foreign eddy current cavitation technology and the typical structure of eddy current cavitation device,a new type of eddy current cavitation test device is designed,which uses multiple eddy current chambers to form more cavitation nuclei and spiral channel to accelerate fluid flow to achieve enhanced cavitation effect.Secondly,focusing on the key issues such as structure design,test control,test and analysis,this paper studies the eddy current cavitation organic wastewater treatment device,puts forward the specific structure of the eddy current cavitation organic wastewater treatment device,designs the test system,and carries out numerical analysis and calculation.The results show that the inlet pressure increases with the increase of the rotational speed of the device motor,and the outlet pressure first increases and then decreases with the increase of the rotational speed of the device motor.The outlet pressure reaches the maximum at 350 r/min.In order to further design large-scale eddy current cavitation equipment with high cavitation efficiency,large amount of wastewater treatment and low energy consumption,the preliminary research foundation is provided.(2)The performance of organophosphorus pesticide trichlorfon wastewater degradation under different conditions was studied.The results showed that the designed eddy current cavitation device had better cavitation effect and degradation performance.The degradation efficiency decreases with the increase of pH value,increases first and then decreases with the increase of rotational speed of the device,increases first and then decreases with the increase of trichlorfon wastewater concentration,increases with the increase of degradation time and increases with the increase of trichlorfon wastewater flow rate.Under the conditions of pH=3,degradation time 2.5h,trichlorfon wastewater concentration 2mg/L,rotational speed 1300r/h,pump pressure 1.21 MPa and flow rate 8L/min,the eddy cavitation effect was the best for trichlorfon wastewater degradation,and the degradation rate was 27.2%.(3)The field drainage containing trichlorfon was collected and tested.The results of optimum pH,rotational speed and degradation time were consistent with those of laboratory simulation of trichlorfon wastewater.Under the conditions of pump pressure 1.88 MPa,flow rate 6.8 L/min,pH=3,rotating speed 1300 r/h and degradation time 3 h,the degradation effect of eddy current cavitation effect is the best,the degradation rate of organic phosphorus is 29.2%,and the removal rate of COD is 39.3%.The results of the study on the degradation of organophosphorus pesticide wastewater by eddy current cavitation can provide reference for similar experiments in the future,and lay a foundation for the practical application of eddy current cavitation technology in the degradation of organophosphorus pesticide wastewater.