The Study On Improved Pretreatment Of Specific Mixed Oily Wastewater

With the development of emission standards,the impact of special sewage on sewage treatment has gradually emerged,among which the problems of temporary storage of oily waste water are more highlighted.This article mainly aims to cut down the indicators of the key pollutants in the sewage in order to reduce the value of pollutants in the water to meet the emission standards.According to the analysis of the value of pollutants in the measured water quality indexes,the following conclusion of experiment are made:the method of flocculation is appropriate for the removal of oil and suspended solids.For this method,when the pH is adjusted to 9,the best organic flocculant was A₁ with an amount of 1.5mg/L and the inorganic flocculant was A₃ with an amount of 200mg/L.Oil content drop from63.4mg/L to 9.5mg/L.The removal rate is 85%.COD drop from 660mg/L to280mg/L.The removal rate is 57%.The method of zeolite adsorption and struvite was tried for the reduction of the ammonia nitrogen value in water and the adsorption effect of zeolite was not ideal.However,the ammoniacal value of ammonia in the struvite deammonization test can be reduced by 40%.The ammonia nitrogen drop form72.3mg/L to 29.1mg/L.The removal rate is 60%.The ozone oxidation process is also adopted in the experiment in order to increase the biodegradability of sewage.When ozone enters water for 15 minutes,further reduce COD in sewage from 296mg/L to168mg/L.Additionally,the biodegradability of special oily wastewater was measured by the intermittent activated sludge method and its respiration curve showed that the biochemical performance of the treated wastewater was good.On the basis of laboratory research,the process flow of field pilot test of“flocculation-ammonia removal-ozon-biochemistry”is determined and carried out he research.Oil content removal rate is 89%.Amonia nitrogen removal rate is 60%.COD removal rate is 40%.The biochemical evaluation of 1:1?1:2?1:3 volume mixed sewage in refinery is carried out by SBR experimental method.The value is bigger than 0.4.It has good biochemical properties.