Experimental Study On Advanced Oxidation Process Further Removing Chemical Oxygen Demand From Oily Wastewater

In recent years,China’s environmental pollution problems have become more prominent.The government and the public have also paid more and more attention to environmental protection.The relevant policies and regulations on air pollution,solid waste and sewage treatment have been continuously introduced,pushing China’s environmental protection cause to a new stage of development.At the same time,a large amount of manpower,material resources and financial resources have entered the field of environmental protection,and various new environmental protection equipments and new methods have been continuously released and applied to various related fields.At present,many pollutant discharge units or individuals are carrying out or have completed the upgrading of relevant equipment methods to meet current environmental protection requirements.However,there are still some shortcomings and shortcomings in many industrial wastewater treatment.In the field of crude oil and refined oil storage and transportation,a large amount of oily sewage will be produced.Some sewage treatment devices before use may not meet current emission standards,especially COD.Some oil depot sewage treatment devices need to be upgraded,and the penalties for excessive discharges are gradually increasing,and sewage management is more stringent.In recent decades,many experts and scholars have conducted in-depth research on advanced oxidation technology for water treatment,which has excellent treatment effect on the treatment of a large number of industrially difficult biochemical wastewater.This paper describes the experiment of deep oxidation to remove the chemical oxygen demand of oily wastewater by advanced oxidation technology.Firstly,the treatment of oily wastewater and its related industrial wastewater is introduced,and then the methods,contents and characteristics of several advanced oxidation technologies are described.Next,three feasible advanced oxidation experiments were carried out to find suitable methods for deep treatment of chemical oxygen demand of oily wastewater,including Fenton oxidation experiment,photocatalytic oxidation experiment and photochemical oxidation experiment.Through the three experimental methods,the advantages and disadvantages of COD removal and the processing results are obtained,and the best treatment methods and conditions are obtained.For the ordinary Fenton advanced oxidation method,the optimal ratio of H₂O₂ to ferrous iron is 8:1 by changing the ratio of H₂O₂ to ferrous iron.With the increase of H₂O₂ dosage,COD degradation The more the amount of H₂O₂ added is basically linear with the degradation rate of COD;the precipitation of iron ions after Fenton experiment shows that iron ion precipitation has a good effect on COD removal in Fenton advanced oxidation method.The amount is even higher than the result of direct oxidation.It is found that the photocatalytic oxidation experiment increases the dosage of the catalyst titanium dioxide,which hinders the irradiation of ultraviolet light to a certain extent,which is not conducive to the catalytic reaction;the effect of using hydrogen peroxide as the oxidant is better than ozone;in the wastewater pH=4 Under the condition that pH=7,pH=9 and pH=12are the only variables,the removal rate of COD is higher than that of pH=7,and the condition of pH=12 is better than the removal of COD at pH=9.The higher the power of the UV lamp,the better the catalytic oxidation effect,the UV lamp has a great effect on the catalytic process;for the photochemical oxidation reaction,when the UV lamp power is 13.3kw per cubic meter,the H₂O₂ dosage is 60ml/h.When the influent COD is 267mg/L,For the petrochemical industry pollutant discharge standard（GB31571-2015）,the processing cost per cubic meter is 16.1 yuan.If it is to be guaranteed to meet the petrochemical industry pollutant discharge standard（GB31571-2015）,the cost per cubic meter is 24.2 yuan.Through experiments and combined with some sewage units,it is concluded that it is feasible to use photochemical method to treat oily sewage.This method is more suitable for the advanced treatment of oily wastewater in oil depots in terms of economy and pertinence,and proposes photochemistry in combination with actual conditions.The structure of the oxidation method,a reasonable solution for the operation mode.