Low-Cost Electronic Nose for Groundwater Contaminants

描述（由申请人提供）：一些美国机构和监管机构需要低成本的化学传感器，用于检测和监测可能污染地下水的环境清理、修复和退役过程。传感器必须能够检测地下地下水中的污染物，并且必须能够在一系列环境中兼容使用。最重要的是，这些客户需要一种低成本的替代方案，以取代目前昂贵且劳动密集型的方法，即使用移动实验室。该项目将带来低成本传感器系统的创新应用，该系统将能够在无人值守的情况下，通过一个推式探头，使用化学电容器阵列和微型预浓缩器，实时检测和监测地下和地下水中的致密非水相液体。SBIR项目的最终目标是为国防部、能源部和其他机构提供一种无需操作人员即可实时绘制和跟踪地下污染羽流的方法。在第一阶段，Seacoast成功地展示了使用微传感器阵列和专有的捕集-净化预浓缩器检测氯化溶剂（特别是TCE和TCA）的可行性，这些氯化溶剂的含量低到足以满足EPA规定的饮用水标准。在第二阶段，海岸建议提高系统的选择性和敏感性，以更好地满足第一阶段顾问确定的需要。该系统具有MEMS微电容传感器阵列，可以监测有毒化学品泄漏，废物污染物和地下水流的变化。预浓缩器捕获污染物并将其释放到微传感器阵列。这些传感器阵列充满了几种化学选择性聚合物，这些聚合物的介电常数在暴露于不同的蒸汽时发生变化，从而对每种化学物质产生指纹响应。在第二阶段，Seacoast将专门开发新材料来提高传感器阵列的选择性，1)通过使用阻抗谱来研究基于聚合物的传感器吸收目标化学物质的机制，2)通过实施模式识别算法来识别传感器响应的化学物质，以及3)通过设计新的预浓缩剂材料来更强地结合这些化学物质。对公共健康和安全最重要的应用是对饮用水、水处理过程和水源的无人监测。潜在市场包括建筑化学过程监测和控制、有毒蒸汽泄漏检测、工业过程控制以及工业健康和安全。将已开发的原型推向其他市场，在这些市场将调查工人和公共卫生、环境卫生和法规遵守情况，以减少财务风险并扩大对该技术的接受程度。

DESCRIPTION (provided by applicant): Several US agencies and regulators require low-cost chemical sensors for detecting and monitoring environmental clean-up, remediation, and decommissioning processes where groundwater may be contaminated. The sensors must be capable of detecting contaminants in the sub-surface groundwater and must be compatible with use in a range of environments. Most significantly, these customers require a low-cost alternative to its current expensive and labor intensive methods, namely using mobile laboratories. The project will result in the innovative use of low-cost sensor systems that will be capable of detecting and monitoring for dense non-aqueous phase liquids in the subsurface and groundwater, unattended, and in real- time from within a push-probe, using a chemicapacitor array and miniature preconcentrator. The ultimate goal of this SBIR project is to provide the DOD, DOE, and other agencies with a method to map and track subsurface contamination plumes in real-time without requiring an operator. In Phase I, Seacoast successfully demonstrated the feasibility of using a microsensor array with a proprietary trap-and- purge preconcentrator to detect chlorinated solvents, specifically TCE, and TCA, at levels low enough to meet EPA mandated levels for drinking water. In Phase II Seacoast proposes to improve the selectivity and sensitivity of the system to better meet the needs identified by the Phase I consultant. The systems have MEMS microcapacitor sensor arrays that can monitor for leaks of toxic chemicals, contaminants from wastes, and changes in groundwater streams. A preconcentrator traps the contaminants and releases them to a microsensor array. These sensor arrays are filled with several chemoselective polymers whose dielectric permittivity changes when exposed to different vapors, creating a fingerprint response for each chemical. In Phase II Seacoast will specifically develop new materials to improve the sensor array selectivity, 1) by using impedance spectroscopy to study the mechanisms by which the polymer-based sensors sorb the target chemicals, 2) by implementing pattern recognition algorithms to identify chemicals for the sensor responses, and 3) by designing new preconcentrator materials that can bind these chemicals more strongly. The most important application to public health and safety is unattended monitoring of drinking water, water treatment processes, and water sources. Potential markets include building chemical process monitoring and control, toxic vapor leak detection, industrial process control, and industrial health and safety. Transitioning the developed prototype to other markets where worker and public health, environmental health and regulatory compliance will be investigated to reduce the financial risks and broaden the acceptance of the technology. PUBLIC HEALTH RELEVANCE: This proposal describes a novel technology that specifically addresses the need for detecting groundwater contaminants and long-term monitoring of contaminated sites, by providing an unattended sensor system that tracks contamination in real-time and transmits contaminant concentrations. Such a system would be used in tandem with other methods, to provide comprehensive contamination management at DOE, DOD, and Superfund sites where ground and water clean-up projects are already underway. The proposed work will focus on detection of chlorinated hydrocarbons, which are described as among the most common pollutants in groundwater and soils at DOE sites.