Study of an A/O Submerged Membrane Bioreactor for Oil Refinery Wastewater Treatment

Abstract

A 55-day experimental study was conducted to investigate the treatment process of oil refinery wastewater using submerged membrane bioreactor (MBR) technology. The results showed that the removal rates for chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD₅) were stable and averaged 92%. The average removal rates for NH₃-N, oil, and turbidity were shown to be 93.7%, 75.3%, and 94.6%, respectively. The removal rates for total phosphorus (TP), total suspended solids (TSS), suspended solids (SS), and phenol were shown to be greater than 98.5%, 97.9%, 93.8%, and 99.9%, respectively. This demonstrated that MBR technology had superior treatment effect on the above contaminants. During the 55-day operation, there was no trace of contamination on the membrane. This illustrated that the polyvinylidene fluoride (PVDF) flat sheet membrane manufactured by Toray Industries (Tokyo, Japan) had the ability to resist contamination.

     

MBR技术在炼油污水生化处理中的应用

为了提高炼厂污水生化处理能力,长庆石化公司采用膜生物反应器技术(MBR)与生化A/O(缺氧/好氧)工艺相结合,处理装置生产中产生的炼油废水。应用结果表明,在工艺控制平稳的情况下,采用膜生物反应器处理含油废水,加快加大了生物处理能力,能有效的降低炼油废水中各种污染物含量,达到污水处理后直接回用或进一步深度处理后回用,实现污水的资源化利用。     

HRT对UASB-SMBR(PTFE)组合工艺处理某油田含油废水性能的影响

 利用升流式厌氧污泥床(UASB)与膜生物反应器(MBR)组合工艺处理含油废水,在不同的水力停留时间(HRT)下考察了系统对NH₃-N、石油类污染物和挥发酚去除以及COD和浊度降低的效果,也考察了膜污染和清洗情况。结果表明,该组合工艺对各种污染物质都有很好的去除效果,出水水质能够满足国家污水综合排放一级标准, NH₃-N、石油类污染物、挥发酚的平均去除率以及CO和浊度的降低率分别达到98.58%、98.33%、99.83%、95.00%和99.84%;污染物的去除效率随着水力停留时间的缩而降低。在实验过程中还发现,在不同水力停留时间下会产生不同程度的膜污染,且水力停留时间的长短与膜染的速率呈反相关关系;采用四步法清洗后,聚四氟乙烯(PTFE)膜的透水性基本完全恢复。UASB-SMBR(PTFE)组合工艺能够稳定运用于含油废水的处理。     

深度处理工艺在炼油污水水质提标改造中的应用

炼油污水厂中的中水回用浓水和反渗透浓水的无机盐类含量高、硬度高、可生化性差.将中水回用浓水和反渗透浓水与污水处理场出水混合处理,采用调节罐+高密度沉淀池+臭氧催化氧化池+改良多级曝气生物滤池+微砂加炭高效沉淀池的工艺流程,处理后出水能够达到DB 61/224—2018《陕西省黄河流域污水综合排放标准》中的指标A标准.运...     

Remediation of Oilfield Wastewater Produced From Alkaline/Surfactant/Polymer Flooding by Using a Combination of Coagulation and Bioaugmentation

In this study, performance of a full-scale combined treatment plant for oilfield wastewater from alkaline/surfactant/polymer flooding was investigated. The combined process consisted of chemical coagulation, hydrolysis/acidification, and bio-contact oxidation. The experimental results demonstrated that chemical coagulation treatment with polymeric ferric sulfate proved to be the most effective in removing the chemical oxygen demand (>80%) from the wastewater under the dosage of 600 mg/m³. The highest acidification efficiency in hydrolysis acidification tank was 25.8% at hydraulic retention time of 20 h. The average values of chemical oxygen demand, biochemical oxygen demand, oil, and NH₃-N of the combined process could be reduced to 116, 19, 4, 11, and 20 mg/L, respectively. The final effluent could meet the class II national wastewater discharge standard of petrochemical industry of China.     

Pretreatment of super viscous oil wastewater and its application in refinery

Wastewater from super viscous oil processing cannot be effectively treated by conventional wastewater treatment plants in refineries because of its high concentration of various organic pollutants. In order to resolve this problem, a number of investigations were conducted in our work to understand the physicochemical properties, sedimentation, demulsification and pretreatment of such super viscous oil refinery wastewater. The results showed that the key issues for pretreatment of this wastewater were： （1） Optimized process parameters were used in the sedimentation and demulsification processes for oil removal to effectively recover oil and remove scum from wastewater; （2） A suitable flocculation process was selected to minimize oil, suspended solids （SS） and chemical oxygen demand （CODcr）. A pretreatment process including three continuous steps： oil removal by sedimentation, oil removal by demulsification, and flotation separation, was proposed and applied in Liaohe Petrochemical Company, PetroChina and the oil content in effluents was less than 200 mg/L and CODcr less than 2,500 mg/L, which completely met the requirement for influent of the conventional wastewater treatment plant, and the recovered super viscous oil reached 5,873 tons in the initial year in Liaohe Petrochemical Company, PetroChina.     

元坝气田蒸发母液深度处理技术研究与工艺设计

元坝气田污水处理厂蒸发母液为三效蒸发系统粗盐结晶后的残液,是复杂组分共存的高盐废水,处理难度极大。研究拟对蒸发母液进行深度处理,通过工艺比选和优化后,蒸发母液经过混凝沉降、CaCl₂除SO2-₄、UV+H₂O₂协同氧化除有机物的组合工艺处理后,出水水质为ρ(固体悬浮物)<50 mg/L,ρ(SO2-₄)为4 200 mg/L,TOC值为459.25 mg/L。出水水质达到厂区采出水处理工艺进水水质要求,可回到厂区水处理工艺及装置进行处理,能有效解决母液处理和积压的难题。该组合处理工艺流程短、简单易维护,在一定程度上实现了蒸发母液的近零排放。      

Hydrogen Sulfide Removal From Petroleum Refinery by Immobilized Thiobacillus ferrooxidans in Fixed-bed Bioreactor

Abstract

In order to remove hydrogen sulfide from petroleum refinery, a fixed-bed bioreactor was constructed by the immobilized Thiobacillus ferrooxidans (T.f) with H-3 carrier. In the state of bioreactor operation, a maximum Fe²⁺ oxidation of 7.24 g/L.h was attained with the aeration of 300 L/h, the dilution rate of 0.6 h^?1, the pH of 2.0, and the temperature of 30°C. And the complex compound forming on the surface of the carrier in the operation of bioreactor was identified as jarosite by chemical analysis and X-ray diffraction analysis. In the fixed-bed bioreactor, the removal of hydrogen sulfide was higher than 99.12%, and the content of H₂S in the exhaust was less than 10 μg/g.     

An Aerated Biofilter for Treating Petrochemical Wastewater

Abstract

The biofilter is one of the most important biological processes applied to treat wastewater. Research on a pilot-scale biofilter treatment of petrochemical wastewater was performed. The volume of biofilter was 1.2 L. In the experiment, the performance is measured with activated carbon, zeolite, and architecture ceramics and engineering ceramics being respectively filled in the biofilter. Hydraulic retention time (HRT), the rate of gas flow, organic loading of influent were examined in the experiment. Experimental results also showed that the optimum process conditions are follows: HRT = 1.5 hr, rate of gas flow 0.29 L/min, and organic loading of 0.74–1.85 kg/(m³ · d). The result showed that the biofilter system exhibits a good effect on chemical oxygen demand (COD), NH₃-N (ammonia nitrate) and turbidity removal, when engineering ceramics is used as packing bed of biofilter. The effluent quality can meet the standard for wastewater use.     

流态化复合载体生物膜工艺处理高含盐炼油污水的研究

流态化复合载体生物膜(FCBR)工艺使用中国石化石油化工科学研究院专利复合载体,可使生化反应器中的微生物浓度较常规流态化生物膜工艺增加近1倍,有效提高了生化处理能力和抗水质冲击能力,适用于处理高含盐炼油污水。某炼油厂的现场连续试验结果表明,在水力停留时间仅为厂内现有生化处理单元50%的情况下(20h),当进水COD质量浓度为185~620mg?L、氨氮质量浓度为18~60mg?L时,FCBR出水的COD质量浓度可降至150mg?L以下,氨氮质量浓度不超过11mg?L,悬浮物质量浓度基本不超过80mg?L,处理效果明显优于现有生化单元,同时具有较强的抗水质冲击能力,可稳定满足后续催化氧化单元的要求,具有工业化应用前景。     

Treatment of oilfield fracturing wastewater

An integrated process was developed for treating an oilfield fracturing wastewater. Under the optimum conditions, the removal efficiencies of chemical oxygen demand, suspended solids (SS), and oil were higher than 98%, and the quality of the final effluent could satisfy the national discharge standard of China. The oxidation process significantly reduced the viscosity and altered the chemical structures of organics in the wastewater. The coagulation process removed a considerable proportion of SS associated with particulate organic matter. The upflow anaerobic sludge bed and biological aerated filter processes played an important role in the post-polish treatment of the wastewater.     

磷酸铵镁沉淀法与SBR工艺协同处理高含磷检修废水的研究

采用磷酸铵镁沉淀法和序列间歇式活性污泥法(SBR)协同处理高含磷检修废水,研究了磷酸铵镁反应中pH值、磷氮摩尔比、镁磷摩尔比等反应因素对高磷检修废水除磷效果的影响。结果表明,当反应中pH=9.5,n(Mg)∶n(P)∶n(N)=1.5∶1∶1时,高含磷检修废水总磷去除效果最佳,去除率可达到98%以上。采用该工艺对污水处理场高磷检修废水进行现场除磷预处理,总磷浓度由256 mg/L降至2.51 mg/L,总磷去除率达99%,效果显著。进一步SBR生化处理后,出水的pH值、COD、NH₃-N、TP和SS等各项指标均符合GB 8978—1996《废水综合排放标准》一级标准,达到了预期的处理目标。     

Treatment of Petroleum Effluent Using a Tubular Electrochemical Reactor

The electrooxidation as a new treatment technology for the purification of petroleum refinery wastewater was used. About 85% COD reduction and complete removal of total petroleum hydrocarbon was achieved for the optimal conditions of current density 30 mA/cm², pH 8, supporting electrolyte 4 g/L, flow rate 120 LPH, and treatment time 24 min using tubular electrochemical reactor. The result shows the applicability of electrochemical technology as an alternative for recycle and reuse of petroleum refinery wastewater. This technology decreases the time required for treating the petroleum effluent, the volume of consumed water, and discharged wastewater.     

Hydrolysis and acidification of activated sludge from a petroleum refinery

The cost-effective treatment of activated sludge that is generated by refining petroleum is a challenging industrial problem. In this study, semi-continuous stirred tank reactors (CSTRs) containing petroleum refinery excess activated sludge (PREAS) were used to comparatively investigate hydrolysis and acidification rates, after the addition of heneicosane (C₂₁H₄₄) (R1) and 1-phenylnaphthalene (C₁₆H₁₂) (R2) to different and individual reactors. Operation of the reactors using a sludge retention time (SRT) of 6 days and a pH of 5.0, resulted in the maintenance of stable biological activity as determined by soluble chemical oxygen demand (SCOD), volatile fatty acids (VFAs) production and oil removal efficiency. The optimum conditions for hydrogen production include a SRT of 8 days, at pH 6.5. Under these conditions, hydrogen production rates in the control containing only PREAS were 1567 mL/L (R0), compared with 1365 mL/L in R1 and 1454 mL/L-PREAS in R2. Coprothermobacter, Fervidobacterium, Caldisericum and Tepidiphilus were the dominant bacterial genera that have the potential to degrade petroleum compounds and generate VFAs. This study has shown that high concentrations of heneicosane and 1-phenylnaphthalene did not inhibit the hydrolytic acidification of PREAS.     

内循环气液固三相流化床处理炼油污水工艺研究

采用自行设计开发的气升式内循环气液固三相流化床反应器,并结合固定化包埋技术,连续处理炼油工业污水。结果表明,在水力停留时间为9 h,固定化微生物颗粒填充率为5%的优化条件下,污水中化学需氧量(COD)及石油类化合物的平均去除率分别约为87%,95%。该反应器的COD容积负荷可高达2.56 kg/(m3.d),具有很强的抗水力负荷冲击和抗COD容积负荷冲击的能力。     

溶气提高脱油型水力旋流器除油效率研究

通过尼可尼气液混合泵向原水中溶入气体,研究了溶气条件下脱油型水力旋流器除油效率的变化规律。结果表明,在溶气条件下,旋流器的除油效率显著增加,在原水中油的质量浓度为200～300mg/L时,出水中油的质量浓度可降到15mg/L以下,平均除油效率达95.5%,提高了9.4个百分点;当气液比Rgl≤3%时,溶气对除油效率的影响不明显,当3%相似文献   

炼油厂高浓度污水处理系统冲击状态运行状况分析

高浓度污水水质平稳是炼油厂实现污水稳定达标排放的关键。通过对南方某大型炼油厂高浓度污水处理系统各工段冲击状态的进出水水质进行全面分析,发现碱渣湿式氧化工段出水中酚和硫化物、污水除油工段出水含油均超过设计要求,生化过程溶氧偏低,导致高浓度污水处理系统冲击状态水质较差。针对发现的问题,提出了相应的解决方案。     

难生物降解炼油污水的“催化氧化+曝气生物滤池”处理技术研究

为解决炼油企业高浓度污水经"隔油+气浮+生化"的传统工艺处理时外排水难以稳定达标的问题,针对该类污水难生物降解的特点,采用"催化氧化+曝气生物滤池"组合处理工艺进行了中试研究。结果表明,利用·OH强氧化反应处理的污水经曝气生物滤池生化处理后,出水中COD、氨氮浓度、油浓度、悬浮物浓度的平均值分别为51.2,5.3,2.3,27 mg/L,COD降低率为83.1%,氨氮、油和悬浮物的平均去除率分别为80.1%,73.4%,61.6%,主要水质指标均达到国家一级排放标准。该技术不需改建炼油厂现有污水处理系统,可实现工业化应用。     

The Potential of Biological Degradation of Refinery Spent Caustic by Sequence Batch Reactor Process

The potential of biological degradation of refinery spent caustic is evaluated in this study, including effects of operating parameters such as pH of influent stream, salinity, and air flowrate on the biotreatment of the spent caustic process. The results show that the sequence batch reactor process by using domesticated activated sludge has an effective biodegradability on refinery spent caustic. The chemical oxygen demand (COD) removal efficiency reached above 80% with an initial COD value of 1000 mg/L, and the degradation rate of sulfide was over 95%. Meanwhile the organic components of the spent caustic were completely biodegraded within one cycle time.     

辽河石化超稠油污水预处理工艺与工程实践

中国石油辽河石化分公司主要加工超稠油,大量高浓度的超稠油污水随之产生,冲击污水场并导致外排水严重超标.对超稠油污水物理化学性质、破乳和净化条件进行深入研究,开发出了以"水质水量调节-破乳除油-旋流油水分离-浮选净化"为主体的超稠油污水预处理工艺,装置建成后运行平稳高效,装置出水油浓度低于200mg/L,CDDcr低于2 500 mg/L,完全满足下游污水场进水要求,当年实现回收稠油5 873 t.