Molecularly Imprinted and Non-imprinted Polymer Particles for Removal of EDCs and PPCPs from Water and Wastewater

Principal Investigator - Banu Örmeci, Associate Professor, Carleton University, 2009 - 2011

Challenge

Over the past decade, several studies have reported trace levels of endocrine disrupting compounds (EDCs), pharmaceuticals and personal care products (PPCPs) in surface waters, drinking water, and wastewater effluents. PPCPs, which are products used for health or cosmetic reasons, have only recently become an area of scientific interest, and their impact on human health and the environment remains unknown.  As EDCs are capable of mimicking or blocking a mammal’s hormonal system, the presence of these compounds in water supplies and their adverse effects on the environment and human health is a growing concern. EDCs and PPCPs are typically released into the environment via wastewater discharges, contaminating surface waters used for drinking water. The concentrations of these emerging contaminants are extremely low; however, several laboratory and field studies have shown that even at low concentrations, these compounds can have an impact on aquatic ecosystems. Adverse health effects on humans are also suspected.

Current treatment plants are neither designed nor effective for the removal of EDCs and PPCPs. Therefore, development of new, innovative, effective and affordable technologies for the removal of emerging compounds is necessary. This project investigated the use of novel molecularly imprinted (MIP) and non-imprinted (NIP) polymer particles as a treatment method for removing emerging compounds from water and wastewater.

Project

The proposed use of MIP and NIP particles for the removal of emerging compounds is a novel approach, and has the potential to achieve excellent removal of EDCs and PPCPs from wastewater and drinking water. The technology is based on the adsorption of EDCs and PPCPs onto polymer particles less than a micron in size.  This would eliminate any generation of waste by-products or daughter compounds that can potentially be more harmful than the parent compound. MIPs, which are designed to have high selectivity and strong affinity for target chemicals, are ideal for industrial wastewater treatment, where high concentrations of specific compounds need to be removed. NIPs, on the other hand, have high potential for general water and wastewater treatment applications, which typically require the concurrent removal of various contaminants.

With an estimated 80 percent removal rate, the results of the study indicate that MIP and NIP particles are very effective at removing a wide range of EDCs and PPCPs from water and wastewater. Binding efficiencies remained high even in the presence of organic matter and other water and wastewater constituents. After treatment is completed, polymer particles can be removed from the water either through coagulation, centrifugal force, or filtration. During the study, MIP and NIP particles with magnetic properties were also created for easy removal via magnetic fields. Magnetic MIP and NIP particles were  shown to have very high binding efficiencies for a range of emerging compounds. Overall, the project successfully achieved the proof-of-concept for the use of MIP and NIP technology and showed their high potential to advance innovation in water and wastewater treatment.

Since MIP and NIP technology is based on adsorption, it does not result in the formation of harmful by-products or daughter products, and, unlike activated carbon, is not susceptible to surface clogging in wastewater. Polymer particles can be designed for specific removal or to achieve broad and simultaneous removal of contaminants.

Outputs

• Workshop on emerging contaminants in the environment and methods for their detection. More than 35 students from Carleton University and University of Ottawa attended the workshop.
• Dissemination of project results was achieved through a combination of meetings, domestic and international conferences, as well as newspaper and radio interviews.

Publications

Murray, A., Örmeci, B., Lai, E. (2011). “Evaluation of Molecularly Imprinted and Non-Imprinted Nanoparticles for Removal of Endocrine Disrupting Compounds from Surface Water and Wastewater.” Water Science & Technology.

Xia, X., Lai, E., and Örmeci, B. (2012). “Ultrasonication-assisted Synthesis of Molecularly Imprinted Polymer-encapsulated Magnetic Nanoparticles for Rapid and Selective Removal of 17β-estradiol from Aqueous Environment.” Polymer Engineering & Science. Vol. 52: 8. Pp. 1775-1783.

Xia, X., Lai, E. and Örmeci, B. (2012). “Duo-molecularly Imprinted Polymer-coated Magnetic Particles for Class-selective Removal of Endocrine Disrupting Compounds from Aqueous Environment.” Environmental Science and Pollution Research.

Hassanzadeh-Khayyat, M., Lai, E., Kollu, K., Örmeci, B. (2011). “Degradation of Diclofenac in Molecularly Imprinted Polymer Submicron Particles by UV Light Irradiation and HCl Acid Treatment.” Journal of Water Resource Protection. Vol. 3: 9. Pp. 643-654.

Presentations

Murray, A., Örmeci, B., and Lai, E. (2011) “Removal of Emerging Contaminants using Imprinted and Non-imprinted Polymers.” Poster Presentation. Canadian Water Network: Connecting Water Resources.

Xia, X., Lai, E., and Örmeci, B. (2011) “Preparation of MIP-encapsulated Magnetic Nanoparticles for Selective Removal of Endocrine Disrupting Compounds from Drinking and Environmental Waters.” Poster presentation. Water Ex. Beijing.

Outcomes

• Improved and expanded treatment technology and management options.
• Potential cost savings in relation to operating and maintaining water infrastructure, via the development of an inexpensive and reusable technology for removing emerging contaminants.  Polymers are cheap and can be inexpensively manufactured in large quantities, enabling full-scale applications in the near future. Polymer particles can also be regenerated and reused repeatedly.
• Potential change in practice – as results indicated that the particles can be removed via enhanced coagulation after the treatment is complete. Thus, the technology can potentially be incorporated into existing wastewater treatment plants without requiring extensive structural or process changes.