1. Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968, United States
2. University of California Center for Environmental Implications of Nanotechnology (UC CEIN), The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968, United States
3. International Fertilizer Development Center, Muscle Shoals, Alabama 35662, United States
4. The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511, United States
5. Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968, United States