IMPROVING THE TREATMENT OF CONTAMINATED AQUIFERS BYDEVELOPING DIRECT-PUSH OXIDAN

描述：水质是美国与公共健康相关的最大问题之一。当一个社区得知他们的饮用水受到污染时，很少有情况比这更能激起公众的强烈抗议。美国地下水质量面临的两大威胁是氯化溶剂或石油的污染。目前，美国估计有2万个地点受到氯化溶剂的污染。这些遗址中的许多都是20至30年前释放的残留物。随着时间的推移，与这些漏油相关的问题的规模和范围只会变得更加严重。同样，含有石油的地下储油罐(UST)泄漏也是美国地下水污染的主要原因之一。在美国目前由联邦政府监管的59万名科技人员中，约有6000人在2011年确认释放。在过去的十年里，人们致力于开发创新的补救技术来对抗这些环境污染物。一种相对成熟的技术是将液体氧化剂注入受污染的含水层或原位化学氧化法(Isco)。成功实施ISCO处理的两个障碍是：污染物位于低渗透层，这些质地较细的区域不容易接受液体注入；或者含水层具有足够的渗透性，可以进行液体注入，但化学氧化剂的粘性导致密度驱动的流动，从而导致氧化剂下沉，而不是处理所需的目标区。为了解决这两个问题，Air Lift Environmental和内布拉斯加大学开发了缓释氧化剂-石蜡蜡烛，当插入低渗透区时，慢慢溶解和拦截污染物。为了防止氧化剂从蜡烛向下迁移，开发了气动循环器，使蜡烛底部的气泡通风或释放，防止氧化剂下沉，同时极大地促进了其水平分布。这项研究的目的是设计和制造带有曝气器尖端的缓释氧化剂蜡烛，可以通过直接推动插入受污染的含水层(即，不需要打井)。这一发展将使安装缓释氧化剂变得更容易、更便宜，并极大地增加其商业吸引力。拟议的研究将分两个阶段进行，在这两个阶段，我们将在大型地下水流动模型中测试直推式蜡烛的原型。具有最有希望的循环器的直推式蜡烛将被放大并进行现场测试，方法是量化氧化剂蜡烛系统垂直均匀输送氧化剂到22英尺的能力。监测油田中的油井。氯化溶剂和石油 产品显然是世界上最大的地下水污染物之一。这项拟议的创新特别旨在提供一种具有成本效益和效率的技术，以对抗受这些污染物影响的公共供水。

DESCRIPTION: Water quality is one of the biggest issues related to public health in the United States. Few situations incite more public outcry than when a community learns that their drinking water has been tainted. Two of the biggest threats to groundwater quality in the U.S. are contamination from either chlorinated solvents or petroleum. Currently, there are an estimated 20,000 sites in the U.S. contaminated with chlorinated solvents. Many of these sites are remnants of releases that occurred 20 to 30 years ago. Left unattended, the size and scope of the problems associated with these spills have only become exacerbated with time. Likewise, leaking underground storage tanks (UST) containing petroleum are one of the leading causes of groundwater contamination in the United States. Of the 590,000 federally-regulated UST currently in the U.S., approximately 6,000 had confirmed releases in 2011. In the past decade, significant efforts have been devoted to developing innovative remedial technologies to combat these environmental contaminants. One technology that is relatively mature is the injection of liquid oxidants into contaminated aquifers or in situ chemical oxidation (ISCO). Two roadblocks to successfully implementing ISCO treatments are when contaminants are located in low permeable layers and these finer textured zones do not readily accept liquid injections or when the aquifer is porous enough for liquid injections, but the cohesive properties of the chemical oxidant results in density-driven flow, thereby causing the oxidant to sink and not treat the desired target zone. To address both problems, AirLift Environmental and the University of Nebraska developed slow- release oxidant-paraffin candles, that when inserted into low permeable zones, slowly dissolve and intercept the contaminant. To prevent the oxidant from migrating downward from the candles, pneumatic circulators were developed that aerate or release bubbles at the base of the candle and prevent the oxidant from sinking while greatly facilitating its horizontal distribution. The objective of this research is to design and manufactue slow-release oxidant candles with aerators tips that can be inserted into contaminated aquifers by direct push (i.e., no wells needed). This development will make it easier and less expensive to install slow-release oxidants and greatly increase its commercial appeal. Proposed research will take place in two stages where prototypes of direct-push candles we be tested in a large groundwater flow model. Direct-push candles with circulators showing the most promise will be scaled up and field tested by quantifying the ability of the oxidant candle system to vertically deliver oxidants evenly to 22-ft. monitoring wells in the field. Chlorinated solvents and petroleum products are clearly among the top groundwater contaminants worldwide. The proposed innovation is specifically designed to provide a cost-effective and efficient technology to combat public water supplies impacted by these contaminants.