Removal of Arsenic and Heavy Metals from Drinking Water

描述(申请人提供)：2001年，美国环保局将饮用水中砷的最高污染水平从50 ppb降低到10 ppb，研究表明，这一下限将防止大量癌症死亡和其他疾病。环保局估计，大约有2294个社区和1000多个非社区(工厂、医院、军事基地等)。为10,000人或更少人口提供服务的供水系统将不得不安装某种形式的砷处理系统。需要新的方法，特别是简单的基于吸附的技术，为这些小型水供应商提供具有成本效益的处理选择。 在第一阶段，ADA表明，其改进的硅酸盐(TM)砷吸着剂，其特点是在惰性硅酸盐基质上形成纳米级的阿卡尼石晶体，在受砷污染的饮用水中的砷容量是商业介质的1.5至4倍。此外，该材料捕获As(III)和As(V)，在饮用水的正常范围内对pH不敏感。成本估算表明，新的吸着剂比现有的商业产品便宜。 在第二阶段，该团队将分析铁基改性硅酸盐(Tm)材料的基本化学成分，并展示基于吸着剂使用的完整除砷系统。系统设计将利用流态化吸附剂接触器中改良的硅酸盐(Tm)的独特物理性质。流态化接触器为处理二氧化硅等污垢物种提供了一些关键的工艺优势，并允许连续去除、再生和组成吸附剂。将在实验室和现场环境中制造和测试中试规模的流态化脱硫剂装置。这些原型将是小容量的，以简化测试要求，但将完全自动化，并将纳入全面设计的所有组件。ADA及其商业化合作伙伴将使用第二阶段演示的数据为社区自来水供应商设计具有成本效益的处理系统。Ada已经与水处理系统的领先供应商Kinetico Inc.合作，为即将到来的2006年合规截止日期将这项技术推向市场。

DESCRIPTION (provided by applicant): In 2001 the US EPA lowered the maximum contaminant level for arsenic in drinking water from 50 ppb to 10 ppb, based on studies indicating the lower limit would prevent a significant number of cancer deaths and other illnesses. The EPA estimates that there are approximately 2,294 community and over 1,000 non-community (factories, hospitals, military bases, etc.) water systems serving 10,000 people or less that will have to install some form of arsenic treatment system. New approaches, particularly simple adsorption-based technologies, are needed to provide cost effective treatment options for these small water suppliers. In Phase I, ADA showed that its Amended Silicate(tm) arsenic sorbent, distinguished by the formation of nanoscale akaganeite crystallites on an inert silicate substrate, had 1.5 to 4 times greater capacity for arsenic versus commercial media in arsenic-contaminated drinking water. In addition, the material captures As(III) and As(V), and is insensitive to pH over the normal range of drinking water. Cost estimates indicate the new sorbent is less expensive than existing commercial products. In Phase II, the team will analyze the fundamental chemistry of the iron-based Amended Silicate(tm) material and demonstrate a complete arsenic removal system based on the use of the sorbent. The system design will utilize the unique physical properties of the Amended Silicate(tm) in a fluidized sorbent contactor. Fluidized contactors provide some key process advantages for dealing with fouling species such as silica, and allow for continuous removal, regeneration, and make up of the sorbent. Pilot-scale fluidized sorbent units will be fabricated and tested in laboratory and field settings. These prototypes will be small capacity to simplify testing requirements, but will be fully automated and will incorporate all components of a full-scale design. Data from the Phase II demonstration will be used by ADA and its commercialization partner to design cost-effective treatment systems for community water suppliers. ADA has teamed with Kinetico Inc., a leading supplier of water treatment systems, to bring this technology to market for the impending 2006 compliance deadline.