NTE: Removal of Toxic Metal Ions from Contaminated Water by Dendrimer Enhanced Ultrafiltration

提案编号：CTS-0086727提案类型：环境倡议的新技术(00-49)主要研究人员：Mamdou S.DialloInstitution：Howard University NTE：通过树枝状分子增强的超滤从受污染的水中去除有毒金属离子有毒金属离子排放到公有水处理厂(POTW)、地表水、含水层和沿海水系统，已在世界各地造成了一个主要的水污染问题。聚合物强化超滤(PEUF)是一种很有前途的处理有毒金属离子污染水的方法。在PEUF中，将对有毒金属离子具有很强结合能力的水溶性聚合物添加到受污染的水中。溶液通过超滤(UF)膜，膜的孔径小于金属离子聚合物的孔径。使用PEUF可以获得高纯度的渗透液。该项目利用纳米化学的最新进展，例如树枝状大分子的发明，为PEUF开发更有效和更具成本效益的功能材料。树枝状大分子是一种高度支化的聚合物，具有可控的组成和结构，由三个组成部分组成：核心官能团、内部支化单元和末端支化单元。树枝状大分子的关键性质，如大小、形状、核心化学、表面化学和多分散性，可以通过明智地选择合成构筑块和反应条件来控制。例如，Adendrimer的端基可以设计为与特定表面相容或不相容，而其核心可以作为金属离子的受体。本项目的总体目标是评估树枝状强化超滤(DEUF)作为一种有效、环境可接受和成本效益高的处理有毒金属污染水的工艺的可行性。商业树枝状大分子正在进行化学修饰，以确定各种形式在分离铜、锌和镉离子方面的有效性。树枝状大分子污染超滤膜的趋势也在测试中。金属制品和机械(MP&AMP；M)行业是DEUF应用的第一目标。在MP&amp；M行业的70,000家公司中，约有40,000家公司产生的废水受到有毒金属离子的污染。根据现行法规，MP&A；M行业必须先处理其受污染的废水，然后才能排放到战时工作场所。美国环保局正在为MP&M行业发布新的、更严格的污水浓度限制。使用目前可用的最佳可行控制技术遵守这些新条例的额外费用估计在每年19.5亿至35.9亿美元之间。美国环保署对PEUF工艺的初步评估表明，与化学沉淀法相比，PEUF工艺具有成本效益。化学沉淀法是MP&P行业的废水处理基准技术。由于树枝状聚合物的金属离子结合能力比目前PEUF中使用的线型聚合物大得多，使用DEUF应该会导致更高效的水净化，并为MP&amp；M行业节省大量资金。

ABSTRACTProposal No.: CTS-0086727Proposal Type: New Technologies for the Environment Initiative (00-49)Principal Investigators: Mamdou S. DialloInstitution: Howard University NTE: Removal of Toxic Metal Ions from Contaminated Water by Dendrimer-Enhanced UltrafiltrationThe discharge of toxic metal ions into publicly owned water-treatment works (POTWs), surface water bodies, aquifers and coastal water systems has caused a major water contamination problem throughout the world. Polymer-enhanced ultrafiltration (PEUF) is emerging as a promising process for treatment of water contaminated by toxic metal ions. In PEUF, a water-soluble polymer with strong binding affinity for toxic metal ions is added to contaminated water. The resulting solution is passed through an ultrafiltration (UF) membrane with pore sizes smaller than those of the metal-ion-laden polymer.Highly purified permeates have been obtained using PEUF. This project exploits recent advances in nanoscopic chemistry such as the invention of dendrimers to develop more efficient and cost effective functional materials for PEUF. Dendrimers are highly branched polymers with controlled composition and architecture consisting of three components: a core functionality, interior branch cells, and terminal branch cells. Critical properties of dendrimers such as size, shape, core chemistry, surface chemistry andpolydispersity can be controlled by a judicious choice of synthetic buildingblocks and reaction conditions. For example, the terminal groups of adendrimer can be designed to be compatible or incompatible with a specificsurface, while its core may act as receptor for metal ions. The overallobjective of this project is to evaluate the feasibility of DendrimerEnhanced Ultrafiltration (DEUF) as an efficient, environmentally acceptable,and cost effective process for treating water contaminated by toxic metalions. Commercial dendrimers are being modified chemically to determine the effectiveness of various forms in separating copper, zinc, and cadmium ions. The tendency of the dendrimers to foul UF membranes is also being tested.The Metal Products and Machinery (MP&M) industry is the first target for theapplication of DEUF. Approximately 40,000 of the 70,000 companies ofthe MP & M industry generate wastewater contaminated by toxic metal ions.Under current regulations, the MP& M industry is required to treat its contaminated wastewater prior to discharge into POTWs. EPA is in the process of issuing new and more stringent effluent concentration limitations for the MP&M industry. The additional costs of compliance to these new regulations using the best practicable control technology currently available are estimated to range from 1.95 to 3.59 billiondollars per year. A preliminary evaluation by EPA of the PEUF process showsit to be cost effective compared to chemical precipitation, the wastewatertreatment baseline technology in the MP& P industry. Because the metal-ionbinding capacity of dendrimers is significantly larger than that of linearpolymers currently used in PEUF, the use of DEUF should result in more efficient water purification and significant savings for the MP& M industry.