Harjyoti Kalita 2008

Harjyoti Kalita is a first-year graduate (PhD) student in Materials and Nanotechnology program at North Dakota State University (NDSU). Before coming to the USA in Fall of 2007, he did his M.Sc. in Chemistry (2006) from the prestigious Indian Institute of Technology (IIT) Guwahati, with his research focusing on catalyst preparation and their applications. Harjyoti did his bachelors of science majoring in chemistry from Gauhati University, India (2004).

His doctoral research focuses on the synthesis of ion-imprinted polymer which will be used to remove arsenic from water and further on to detect aqueous arsenic.
Email: Harjyoti.Kalita@ndsu.edu
Phone # 701-200-5109

Fellow: Harjyoti Kalita
Advisor: Achintya Bezbaruah, Ph.D., Assistant Professor, Department of Civil Engineering, North Dakota State University.
Co-Advisor: Bret Chisholm, Ph.D., Senior Research Scientist, Center for Nanoscale Science and Engineering and Adjunct Professor, Polymers and Coatings, North Dakota State University.
Matching Support: North Dakota State University.
Degree Progress: Ph.D. in Environmental Engineering expected in Fall 2010

Ion imprinted polymer for Removal and Monitoring of Arsenic

Project Objectives:

• Preparation of an ion imprinted polymer (IIP) for selective removal of arsenic from water
• Selectivity study of the IIP in presence of different ionic particles
• Determine the reusability time and number for effective removal of arsenic
• Preparation of a new ion imprinted potentiometric sensor for arsenic metal ion

Research:

Arsenic present in water is a serious environmental and health concern because of the toxicity of arsenic on human and on other living organisms. Arsenic usually occurs naturally in groundwater although some arsenic based pesticides and preservatives may also contribute. The U.S. EPA has set 0.010 parts per million (10 µg/L) as the arsenic standard for drinking water in 2006. The maximum contaminant level or MCL of 10 µg/L has created an urgent need of new technology for arsenic removal from water and sensing.

Arsenic is present in water in tri- and penta-valent forms. Different Processes are presently used to remove arsenic. However, most of the conventional arsenic removal processes can not remove As(III) and As(V) simultaneously. They can treat either As(III) or As(V), and, hence, a pretreatment in the form of oxidation or reduction is needed. The need for an additional unit process adds to the capital and operation costs of treatment.

To overcome this limitation it is proposed to synthesize ion-imprinted polymer for the removal of both As(III) and As(V) simultaneously. Cross-linkers will be used in the polymer which can bind both As(III) and As(V) and reduce As(V) to As(III). Hence, arsenic removal could be done in one step. This research will proceed further on to develop sensors with low response time and high arsenic detection efficiency.

Progress:

Proof-of-concept experiments are in process. Different cross-linkers are being experimented upon to select the best candidates for binding of As(III) and As(V) and reduction of As(V) to As(III).

Significance:

The outcome from this work will have a universal appeal and will be very relevant to North Dakota. Arsenic contamination is a major concern in southeast North Dakota (568 sq mile area in Sargent, Ransom and Richland counties are affected). The IIP developed will find potential use in large and small water treatment plants including point-of-use treatment units. Ion-imprinted chemical sensor technology will have potential applications in clinical diagnostics, environmental and food analyses as well as in illicit drugs detection, genotoxicity and chemical weapons.