The Study On Advanced Treatment And Reuse Of Emulsion Wastewater

The main compositions of the emulsion wastewater are machine oil,surfactant,soluble organic matter and suspended solids,etc.Due to it contains high organic matter content,high oil content,large emissions and strong pollution,so it has important significance that the emulsion wastewater undergoes some processes before being reused.Membrane fouling is still an important factor restricting its development.This study was related to a factory of Beijing eco-island which involves emulsion wastewater collection and treatment,evaluated its nature of water quality and carried out a study to test the feasibility by advanced oxidation and PSB biochemistry enhanced membrane technology.Firstly,the experiment has examined the effect of ultrasonic,ozone and Fenton oxidation technology on biodegradability of emulsion wastewater,in addition,it has studied and optimized the best service conditions for Fenton oxidation.Then,for the emulsion wastewater,the method of introducing PSB to Fenton oxidation mainly studied the growth laws and conditions of PSB and the effect of operating conditions such as illumination,DO,HRT and immobilization etc on treatment result and corresponding rule during biological treatment for PSB.Followed by biological treatment,the wastewater was carried out depth treatment through ultrafiltration and reverse osmosis,we mainly studied the feasibility and operational reliability of processes and determined parameters like temperature,pressure and the cleaning period in the process of ultrafiltration and reverse osmosis membrane operation.About the effect on improving the biodegradability of emulsion wastewater,Fenton oxidation was superior to ultrasonic,while the latter was better than ozone.The Fenton oxidation system will not only improve the bio degradability of wastewater,but also degrade and remove the organic matter with chromophore in wastewater.The treatment effect could reach the best when the initial pH value for Fenton oxidation was 2.5,the dosage of Fe2+ was 2500mg/L,[H2O2]/[Fe2+](mol/mol)was 40,the reaction time was one hour and pH was 9.0?10.0 for sedimentation,which B/C level improved to 0.52 from 0.16 with the CODCr removal rate of wastewater reaching 60.8%.The experiment determined that the growth cycle of PSB was about seven days,and the logarithmic phase of the bacteria was two to four days after the cultivation,through the analysis of the growth rule and the cultivation conditions of the PSB.Under the light micro aeration condition,short time and high efficiency for immobilization PSB could be realized by adjustment and optimization to biochemical treatment process of Fenton oxidation solution.Mix PSB(following sodium alginate embedding fixation)with wastewater by the proportion of 1:4 with pH level of new mixed liquor appeared at 7.0?8.0,the removal effect for wastewater could reach the best(73.5%,231.Omg/L for CODCr,)when meeting 30? of constant temperature and light micro aeration condition and the waterpower remained for 60 hours.Employ the UF-RO group technology to treat the emulsification water following PSB,the ultrafiltration membrane had a good retention effect on residual macromolecule and the membrane fouling could be wiped off by wash of tap-water.System operation parameters as follows:UF was filtered by normal temperature and constant pressure cross-flow with the feed water pressure 0.1 MPa,1LPM feed water flow rate,and water production rate of 90%,and RO was filtered by constant speed with dosing 40mg/L high salt scale inhibitor,water flow 0.1 LPM,water production rate 50%.Under the above conditions,the salt rejection was 98.0.%,the sulfate radical was 98.1%and the total hardness removal rate was 99.4%.The experiment showed that it was feasible to apply the combination technology of Fenton oxidation-alginate for the combination of PSB to strengthen UF-RO treatment of the emulsion wastewater.About the emulsion wastewater after treatment,the CODCr could fell to 63.7mg/L from 2224.3mg/L,the sulfate radical could drop to 148.6mg/L from 7078mg/L after a series of group technology treatment,and the effluent quality could reach the regeneration water quality standard of water as industrial water.