Water Resources Research Act Program

Details for Project ID 2009ND188B

Ion Imprinted Polymer for Removal and Monitoring of Arsenic (Phase II)

Institute: North Dakota
Year Established: 2009 Start Date: 2009-03-01 End Date: 2011-02-28
Total Federal Funds: $19,000 Total Non-Federal Funds: $38,002

Principal Investigators: Achintya Bezbaruah, Bret Chisholm

Abstract: The threat of arsenic pollution in drinking water is a serious environmental and health concern because of the toxicity of arsenic on human and on other living organisms. In drinking water supplies, arsenic is usually naturally occurring although some pesticides and preservatives also contain arsenic. The US EPA recently lowered the maximum containment level (MCL) for arsenic to 10 g/L (10 ppb) from 50 g/L (50 ppb) in drinking water. This new MCL has created an urgent need of low capital and technology intensive arsenic removal and sensing in water, more particularly in small utilities and rural communities. Different technologies have been developed to remove arsenic from both water and wastewater. These technologies include the conventional processes of oxidation, co-precipitation and adsorption onto coagulated flocs, adsorption onto sorptive media, ion exchange, and membrane filtration. At pH 6-9, arsenic occurs in pentavalent form [As(v)] and, thus, this form of arsenic is more easily removed from water than trivalent arsenic [As(III)] by the conventional processes (e.g., ion exchange, reverse osmosis and electron diffraction). However, As(III) is the predominant form normally found in groundwater, and due to its weak dissociation constant, As(III) cannot be removed by the conventional processes. The present research proposes a method for treatment of arsenic which is based on the emerging ion imprinting technology that will have the ability to remove both As(III) and As(V) very efficiently without any pre-treatment. Again to date, arsenic in the environment is measured with spectroscopic techniques, including atomic fluorescence spectroscopy (AFS), graphite furnace atomic absorption spectroscopy (GFAAS), hydride generation atomic absorption spectroscopy (HGAAS), inductively coupled plasmaatomic emission spectrometry (ICPAES), and inductively coupled plasmamass spectrometry (ICPMS). These techniques are well established but require samples to be collected and transported to a centralized laboratory for analysis because the equipment is bulky, expensive, and requires significant operator expertise. These techniques are time intensive and the sample handling procedure may introduce errors. In-situ and ex-situ measurements using simple hand-held instrument are highly desirable because they can provide quick detections of arsenic while minimizing errors, labor, and cost associated with the spectroscopic methods. Such a method has become even more relevant with the US EPA is new MCL of 10 g/L, more particularly for small and rural utilities. This project proposes ion imprinted polymer based potentiometric sensor to measure As(III) and As(V) in environmental samples. The objectives for this second phase of research are: 1) Sorption and selectivity study of IIP for arsenic ion, and 2) Fabrication and testing of As sensors.