| 英文摘要: | 1626157
Camacho, Lucy
Understanding the occurrences and chemistry of metal species in the environment poses a research challenge to the areas of chemistry, agriculture, and chemical and environmental engineering. Elemental speciation is important because, for many elements, properties such as toxicity or nutrient value, mobility, and volatility, depend on the species or chemical form of the element present in the environment. A multidisciplinary group of faculty members from the Environmental Engineering, Chemical Engineering, Chemistry, Agriculture, Agribusiness, and Environmental Sciences departments at Texas A&M University-Kingsville (TAMUK) will conduct research, educational, and outreach activities using the LC-ICP-MS instrument. TAMUK is a Minority Serving Institution and is the only institution with an Environmental Engineering Ph.D. program in South Texas. This project will allow preparing STEM students, particularly Hispanic, with skills in conducting high quality and competitive research in critical interdisciplinary environmental areas. This project will allow TAMUK to attract inter-institutional research and education collaboration from other institutions in South Texas, particularly Texas A&M University in Corpus Christi (TAMUCC) and the University of Texas Rio Grande Valley (UTRGV), since no other institution in the region possesses a hyphenated instrument for species identification and quantification and multi-element determination. This project will directly impact the research expertise of graduate and undergraduate Hispanic students at TAMUK and other research/educational institutions in South Texas. It is anticipated that more than 150 graduate students at TAMUK will become involved in laboratory-activities related to the instrument over the three years of the grant. Due to the strategic location of TAMUK in South Texas, the potential for international and interdisciplinary experiences for students exists, which will create a broader spectrum for future global collaboration. For this purpose, summer research exchange programs between institutions at the U.S.-México border will be promoted.
This project will advance knowledge on speciation reactions that metal ions undergo in environmental systems due to natural and anthropogenic causes. This project is divided in seven sub-projects that will allow identifying problematic ion species present in a broad range of environments, as well as determining how to negate the toxicity and mitigate the effect of these ions species on the environment. The objectives of the sub-projects are to 1) determine the adsorption of As(III)/As(V) from brackish groundwater on manganese oxide-modified natural zeolite (MCZ); 2) conduct a comparative study of the aqueous-phase adsorption of sulfamethazine (SMN) onto powdered activated carbons in the presence of heavy metal ions; 3) evaluate alternative inorganic reductants for stimulating autotrophic reduction and immobilization of uranium (VI) at in-situ recovery mining sites; 4) conduct element speciation analysis of trace metal- and metalloid-containing compounds, such as vanadium (V), nickel (Ni), mercury (Hg/Hg(II)), arsenic (As(III)/As(V)), and sulfur (S/S(II)/S(III)), in petroleum-related materials; 5) conduct an assessment of nutrient foliar spray impact on citrus production; 6) evaluate the reduction of combustion flue gas emissions of mercury by enhanced oxidation with hydrogen peroxide; and 7) determine the immobilization of homogeneous catalysts for atom economical alkene and alkyne functionalization. The LC-ICP-MS instrument will be used by the sub-projects to 1) quantify the transformation of As(III) into As(V) species during the adsorption on MCZ; 2) quantify arsenic, antimony and copper on the adsorption of SMN onto powder activated carbon materials; 3) quantify uranyl-carbonate concentrations by using inorganic or organic reductants; 4) analyze vanadium (V), nickel (Ni), mercury (Hg/Hg(II)), arsenic (As(III)/As(V)), and sulfur (S/S(II)/S(III)) speciation in collected crude oil and gas condensate samples from the Eagle Ford Shale; 5) measure chelated elements, such as Ca, B, Cu, and Si that will be applied as foliar sprays to young grapefruit leaves; 6) provide a more distinct separation of mercury species and increase the analytical precision, resulting in better reproducibility and optimization of experimental runtimes; and 7) monitor possible catalyst leaching effects from reaction solutions immobilized by an alkyl tether on isotactic-propylene/hexane copolymer or silica. Results from the sub-projects will 1) provide an alternative method to remove and mitigate As species that have potential health effects and that have been found in fresh water aquifers in the Gulf Coast of Texas; 2) allow mitigate the environmental impact of antimicrobial SMN drug released to the environmental through excretion by cattle and swine; 3) provide a process for groundwater restoration at uranium in-situ recovery (ISR) sites in South Texas; 4) allow understanding the role that species have on catalyst poisoning mechanisms; 5) allow developing new management practices and guidelines for growing crops that are better adapted to abiotic and biotic stresses in the Lower Rio Grande Valley; 6) help implement enhanced oxidation with hydrogen peroxide to produce soluble species of mercury that can be removed by absorption from scrubbers in power plants; and 7) provide insight into atom economical processes, which do not generate any waste products and are therefore of great importance for industrial applications. |