SBR Treating High-salinity Oil Exploration Produced Wastewater

Abundant of oily wastewater will be generated from oil exploration, refining and machining processes. High-salinity oil exploration produced wastewater is difficult to be treated as it contains plenty of dissolved inorganic substances and organic pollutants which are difficult to be degarded. Therefore,the doable and economical biological treatment is full of significance in improving environment.This paper summarizes the advantages of adopting Sequencing Batch Reactor (referred to as SBR) for treating high salinity oil exploration produced wastewater on the basis of the research to past studies. In addition, acclimation completion time and optimum opertion conditions of SBR system are concluded in accordance with the testing results of adopting SBR method to treat manual high-salinity oil exploration produced wastewater. Futher more, halophilic bacteria separation testing is conducted by using the sluge-water mixed liquids from SBR reactor as samples.The main conclusions are listed below:1.Research on sludge acclimation:It takes 49 days to complete the sludge acclimation by adopting SBR method and enhancing the salt concentration in the wastewater。Enhancing the salt concentration will generate an adverse effect to the watstewtaer treatment effect only at each initial stage, then the removal efficiency of CODcr will be promoted as the salt concentration is enhanced. The removal efficiency of CODcr reaches at 80% when the salt concentration in the wastewater is maximum.2.Research on operation conditions of SBR System:Aeration time, temperature and pH have impacts to the removal efficiency of CODcr and NH3-N.According to the testing results, the optimum operation conditions of SBR system are:6hours for aeration time,8 hours for one operation shift, three shifts per day,30℃for controlling temperature and 7.5 for pH.3.Research on the shock loading resistance capacity of SBR system under the optimum operation conditions:The factors affecting the SBR reactor included the organic load, load of ammonia nitrogen and salinity. Based on an overall consideration of various factors, the anti-salinity impact of reactor was weaker than the other two and long time was required to restore stability after the impact. The restore-stability time of system to organic load is 102 h, to ammonia nitrogen load is 120 h and to salinity is 144 h, respectively.4. Research on activated sludge:During the whole experiment process, the sludge in SBR reactor shows good settleability.83.92% of the SV30 index falls between 15% and 40% and the SVI index is less than 150mL/g,64.92% of the SVI index ranges from 60～100mL/ g.5.Research on the separation of halophilic bacteria:Two different bacteria are formed on two different cultivation medias after enrichment, cultivation, separation and purification. Aa and Bb are added to the reactor separately for comparison testing but no significant difference.