A Photoelectrocatalytic Device for Removing MTBE from Water

一种去除水中MTBE的光电催化装置

• 批准号: 7748234
• 负责人: TERENCE PATRICK BARRY
• 金额: $ 10万
• 依托单位: AQUAMOST, INC.
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2010-08-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7748234
• 关键词: Acute; Adsorption; Air; Anodes; Beds; Benzene; Carbon; Carbon Dioxide; Carcinogens; Cathodes; Characteristics; Chemicals; Cost-Benefit Analysis; Country; Data; Devices; Economics; Effectiveness; Electrodes; Electrons; Engineering; Environment; Environment and Public Health; Environmental Health; Environmental Pollutants; Ethers; Evaluation; Excision; Farming environment; Feedback; Funding; Gasoline; Genetic Recombination; Health; Human; Ionic Strengths; Ions; Isomerism; Kinetics; Laboratories; Life; Marketing; Measures; Membrane; Methods; Metric; Operative Surgical Procedures; Osmosis; Performance; Phase; Phase I Clinical Trials; Poisoning; Polishes; Process; Production; Pump; Reaction; Resistance; Resources; Risk; Running; Sampling; Site; Soil; Solutions; Staging; System; Technology; Testing; Toluene; Toxic effect; Ultraviolet Rays; United States; Water; Water Pollutants; Xylene; aqueous; base; commercialization; comparative efficacy; cost; cost effectiveness; design; drinking water; efficacy testing; ethylbenzene; experience; hazard; improved; interest; meetings; methyl tert-butyl ether; microbial; mineralization; organic contaminant; oxidation; pollutant; prototype; public health relevance; remediation; research study; residence; scale up; success; vapor; wasting; water solubility

DESCRIPTION (provided by applicant): There are currently between 500,000 and 2.5 million leaking underground fuel storage tanks in the United States. Soluble organic compounds that enter the groundwater from these tanks can be a major hazard to public health and the environment. Two contaminate classes are of particular concern: (1) BTEX fuel additives consisting of benzene, ethyl benzene, toluene, and three isomers of xylene, and (2) fuel oxygenates, particularly methyl tert-butyl ether (MTBE). Both BTEX and MTBE have acute and long-term toxic effects, and may be carcinogenic. Given these risks to human health, considerable federal and private resources are being expended to remove these compounds from contaminated groundwater sites throughout the country. Its unique chemical characteristics (e.g., high water solubility and polarity) make MTBE more difficult to remove from contaminated groundwater than BTEX. Although MTBE can be treated with granular activated carbon (GAC), it diminishes the bed life of GAC by over 75% compared to BTEX. Also, unlike BTEX, MTBE is generally resistant to microbial degradation. Various other remediation methods have been investigated in an attempt to find an effective, economical method to remove MTBE, including phytoremediation, soil vapor extraction, multiphase extraction, air sparging, membranes (reverse osmosis), ozonation, and photocatalytic oxidation (PCO). This project will employ proprietary photoelectrocatalytic oxidation (PECO) devices to completely remove MTBE from contaminated groundwater. In PECO, an electrode is coated with a TiO2-based photocatalyst that is irradiated with UV light. A potential of 1 to 5 V is applied between the photoanode and a cathode to minimize recombination of photogenerated electrons and holes and improve the efficiency of the system. Flow- through PECO prototypes will be used in replicate laboratory experiments to evaluate the effects of NaCl concentration, initial MTBE concentration, and competing contaminants (e.g., BTEX) on the degradation kinetics, and degree of mineralization of MTBE and its expected reaction by-products. Compounds will be measured by TOC and GC-MS. Additional larger commercial-scale PECO units will be fabricated and tested at actual MTBE-contaminated sites to evaluate the effectiveness and costs of MTBE remediation by PECO. Based on the results of these evaluations, additional trials and studies will be designed in Phase 2 for remediation of other problem organic contaminants. A particular interest will be determining the economic viability of employing PECO as the first stage of a two-stage PECO/GAC treatment system. PUBLIC HEALTH RELEVANCE: The fuel additive methyl tert-butyl ether (MTBE), and other organic carcinogens associated with gasoline (e.g, BTEX), can enter the nation's drinking water from leaking underground fuel storage tanks, fuel spills, and in the course of normal use. To alleviate these environmental health risks, a highly efficient, and cost-effective photoelectrocatalytic oxidation technology has been developed to remove organic pollutants from water. This project will test the utility of this technology for treating MTBE contamination, both as a stand-alone treatment and as the first stage of a two-stage treatment process in which granular activated carbon is used to polish the water.

描述（由申请人提供）：目前在美国有50万至250万之间泄漏的地下燃料储罐。从这些储罐中进入地下水的可溶性有机化合物可能对公共卫生和环境构成重大危害。两种污染类别特别关注：（1）由苯，乙烯，甲苯和三种二甲苯的三个异构体组成的BTEX燃料添加剂，以及（2）燃料含氧，尤其是甲基丁基丁基醚（MTBE）。 BTEX和MTBE都有急性和长期毒性作用，并且可能具有致癌作用。鉴于人类健康的这些风险，正在花费大量的联邦和私人资源来从全国各地受污染的地下水遗址中清除这些化合物。与BTEX相比，它独特的化学特性（例如，高水溶性和极性）使MTBE更难从受污染的地下水中取出。尽管MTBE可以用颗粒活性碳（GAC）处理，但与BTEX相比，GAC的床寿命降低了75％以上。同样，与BTEX不同，MTBE通常对微生物降解具有抵抗力。已经研究了其他各种其他补救方法，以寻找一种有效的，经济的方法来去除MTBE，包括植物蒸发，土壤蒸气提取，多相提取，空气散发，膜，膜（逆渗透），Ozonation，Ozonation，Ozonation和Metocatalytic氧化（PCO）。该项目将采用专有的光电催化氧化（PECO）设备，以完全从受污染的地下水中清除MTBE。在PECO中，电极涂有基于TiO2的光催化剂，该光催化剂被紫外线照射。在光阳极和阴极之间应用1至5 V的电势，以最大程度地减少光生电子和孔的重组，并提高系统效率。流通PECO原型将用于复制实验室实验，以评估NaCl浓度，初始MTBE浓度和竞争污染物（例如BTEX）对MTBE降解动力学的影响（例如BTEX）及其预期的反应。化合物将通过TOC和GC-MS测量。将在实际被MTBE污染的站点制造和测试其他较大的商业规模的PECO单元，以评估PECO的MTBE补救的有效性和成本。根据这些评估的结果，将在第2阶段设计其他试验和研究，以修复其他问题有机污染物。特别的兴趣将决定使用PECO作为两阶段PECO/GAC治疗系统的第一阶段的经济可行性。 公共卫生相关性：燃料添加剂甲基丁基醚（MTBE）和其他与汽油相关的有机致癌物（例如BTEX）可以从泄漏地下燃油储罐，燃油溢出物以及正常使用过程中进入美国的饮用水。为了减轻这些环境健康风险，已经开发出一种高效且具有成本效益的光电氧化技术，以清除水中的有机污染物。该项目将测试该技术用于治疗MTBE污染的实用性，既是独立的治疗方法，也是两阶段治疗过程的第一阶段，其中使用颗粒状活性碳来抛光水。