【作者】 张雷；

【导师】 付维贵； 韩永良；

【作者基本信息】 天津工业大学 ， 材料与化工（专业学位）， 2025， 硕士

【摘要】 中空纤维陶瓷膜因其具有高孔隙率、高比表面,以及优异的耐温性、化学稳定性和环境友好的材料特性,在含油废水处理领域呈现出巨大应用潜力,但在实际应用中,仍面临膜污染及清洗再生难题的多种挑战,制约其效能发挥。本研究通过表面改性策略,以晶须莫来石中空纤维陶瓷膜作为支撑体,运用真空辅助浸涂和烧结技术制备光催化层,并进一步通过水热合成法原位生长压电光催化层,成功构建了兼具光催化和压电光催化多机制协同自清洁功能的复合陶瓷膜体系,显著提升了膜的抗污染性能与再生能力。主要研究内容如下:首先,采用水热法合成TiO₂纳米管（TiNTs）,随后将硫脲与其共混烧结,制备出硫掺杂TiO₂纳米管（S-TiNTs）。理论分析结合实验验证表明,硫元素主要以表面掺杂的形式存在于S-TiNTs中,并且产生了丰富的氧空位（Ovs）,进而使带隙能减小至2.43 eV。模拟太阳光照下,S-TiNTs表现出优异的光催化降解效果:甲基橙（MO,10 mg/L）溶液在40 min内降解效率高达99%;机油乳液（Engine oil emulsions,1000 mg/L）经过85 min降解,效率达到80%;而油田采出水（OPW,1194 mg/L）经过140 min的处理,降解效率同样达到80%。其次,通过真空辅助浸涂与烧结技术,将S-TiNTs与中空纤维陶瓷基膜（M₀）结合,制备出硫掺杂TiO₂纳米管复合中空纤维膜（M/S-TiNTs）。研究结果表明,M/S-TiNTs在连续12 h分离机油乳液和OPW后,通量分别保持在621.25 L·m^-2·h^-1和288.66 L·m^-2·h^-1,截留率均超过98%;在静态光催化处理后,膜通量恢复率（FRR）分别提升至83.1%和57.6%,显著优于M₀的38.9%和33.7%;经过M/S-TiNTs动态光催化分离2 h后,机油乳液和OPW的渗透液总有机碳（TOC）浓度分别降至2 ppm和16 ppm以下,满足国家的回注标准。最后,通过水热法原位生长钛酸钡钙(Ba_0.8Ca_0.2TiO₃),制备出压电光催化复合膜（M/S-TiNTs@BCTO）。结果表明,M/S-TiNTs@BCTO表现出优异的亲水性（初始水接触角在10 ms从5°降至0°）和卓越的压电-光催化自清洁能力（单/双周期的FRR分别达到94.5%和93.6%）。经过复合膜压电光催化分离2 h后,机油和OPW渗透液TOC浓度分别降至1 ppm和13 ppm,满足国家的回注标准。该协同作用机制为复杂工况下的膜污染控制提供了新思路,本研究对推动自清洁陶瓷膜技术在处理石化行业含油废水与规模化应用具有指导意义。更多还原

【Abstract】 Hollow fiber ceramic membranes have demonstrated remarkable potential in oily wastewater treatment due to their high porosity,large specific surface area,exceptional thermal resistance,chemical stability,and environmental benignity.However,their widespread practical applications are still severely hampered by persistent challenges,such as intractable membrane fouling and difficulties in membrane cleaning and regeneration.In this study,a mullite whisker hollow fiber ceramic membrane was used as the substrate.Subsequently,photocatalytic layers were successively deposited through vacuum-assisted dip-coating and sintering processes,followed by in-situ growth of the piezo-photocatalytic layers via hydrothermal synthesis.The resulting composite ceramic membrane system ingeniously integrated synergistic photocatalytic and piezo-photocatalytic self-cleaning mechanisms,thereby substantially enhancing its anti-fouling performance and regeneration capacity.The main research aspects are as follows:（1）The TiO₂nanotubes（TiNTs）were synthesized via hydrothermal method,followed by sulfur doping through thiourea co-sintering to prepared sulfur-doped TiO₂nanotubes（S-TiNTs）.Through a combination of theoretical analysis and experimental verification,it was revealed that sulfur mainly exists in the form of surface doping in the S-TiNTs.This doping generates abundant oxygen vacancies（Ovs）,effectively optimizing the band structure and reducing the bandgap energy to 2.43 eV.Under simulated solar irradiation,S-TiNTs exhibited outstanding photocatalytic degradation performance:99%degradation efficiency was achieved for methyl orange（MO,10mg/L）within 40 min,80%degradation efficiency for engine oil emulsions（1000mg/L）in 85 min,and 80%degradation efficiency for oilfield produced water（OPW,1194 mg/L）after 140 min.（2）The S-TiNTs composite hollow fiber membrane（M/S-TiNTs）was fabricated through vacuum-assisted dip-coating and sintering techniques,integrating S-TiNTs with the mullite whisker hollow fiber ceramic substrate（M₀）.During 12 h continuous separation,M/S-TiNTs maintained stable permeate fluxes of 621.25 L·m^-2·h^-1and288.66 L·m^-2·h^-1for engine oil emulsions and OPW respectively,with rejection rates exceeding 98%for both feed solution.After the static photocatalytic treatment during the three filtration cycles,the flux recovery rates（FRR）of M/S-TiNTs reached 83.1%and 57.6%,outperforming M₀,which had much lower recovery rates of 38.9%and33.7%,respectively.Dynamic photocatalytic filtration further reduced the total organic carbon（TOC）concentrations to<2 ppm and<16 ppm for engine oil emulsions and OPW permeates,respectively,thus meeting the national reinjection standards.（3）The piezo-photocatalytic composite membrane（M/S-TiNTs@BCTO）was fabricated via hydrothermal in situ growth of barium calcium titanate(Ba_0.8Ca_0.2TiO₃)on M/S-TiNTs,demonstrating exceptional hydrophilicity（the initial water contact angle decreased to 0°within 10 ms）and robust self-cleaning capability,achieving single-cycle and dual-cycle FRR of 94.5%and 93.6%,respectively.The TOC concentrations of the engine oil emulsions and OPW permeates were reduced to 1ppm and 13 ppm,respectively,after separation by M/S-TiNTs@BCTO,meeting the reinjection standards.This integrated synergistic photocatalytic and piezo-photocatalytic oxidation mechanism offers an innovative solution for controlling membrane fouling under complex operating conditions.This study provides crucial insights for promoting the large-scale application of self-cleaning ceramic membranes in petrochemical wastewater treatment.更多还原