Archeological Testing and Data Recovery at 41ZV202, Zavala County, Texas

At the request of the Texas Department of Transportation, Environmental Affairs Division (TxDOT-ENV), the Center for Archaeological Research (CAR) of The University of Texas at San Antonio (UTSA) conducted archeological significance testing at 41ZV202, a prehistoric site located in northwestern Zavala County, in March of 2003. The work, conducted under Texas Antiquities Permit No. 3071 issued to Dr. Steven A. Tomka, was done in anticipation of the potential widening by TxDOT of FM 481. While materials dating to the Archaic were also present, the testing demonstrated the presence of significant Late Prehistoric (Austin Interval) deposits with good integrity within a portion of the TxDOT right-of-way (ROW). As TxDOT construction could not avoid these deposits, and as both the Texas Historical Commission (THC) and TxDOT concurred with CAR’s recommendations that the deposits were eligible for listing on the National Register of Historic Places (NRHP) under criterion d of 36CFR 60.4, data recovery investigations were initiated. CAR began that work in July and August of 2003. The testing permit was amended to include the data recovery efforts. Dr. Russell Greaves served as project archeologist for both the testing and data recovery effort at 41ZV202. The testing and data recovery work consisted of the excavation of a 53-m-long Gradall trench, exposing and profiling a 75-m-long road cut, and the hand excavation of 52 1 x 1 meter units that removed approximately 34.6 m3 of soil. Testing identified two large, dark stained areas designated Features 4 and 5, an associated hearth (Feature 7), and a small cluster of FCR (Feature 6). Just over 1,000 chipped stone items were recovered, including several Scallorn points, one reworked dart point, several bifaces, and two flake tools. Eleven AMS radiocarbon dates were submitted from deposits, with eight clustering around 1000 BP. Data recovery efforts defined FCR features 8 through 13. In addition, 24 arrow points, several dart points, a variety of unifacial and bifacial tools, a small number of cores, roughly 6,000 pieces of debitage, and a variety of burned sandstone, were recovered. We also collected small quantities of bone and mussel shell along with about 14,350 gastropod shells, and a variety of soil samples. Finally, all calcium carbonate nodules were retained from the screens. Following the completion of data recovery efforts, the CAR was directed by TxDOT to develop a research design for the analysis of the material from 41ZV202. TxDOT and THC accepted that research design in November of 2004, at which time the CAR began analysis and report production. Unfortunately, by 2005 project archeologist Russell Greaves had left the CAR. At that point, CAR assistant director Dr. Raymond Mauldin took over the project. The analysis of the 41ZV202 Late Prehistoric data outlined in this report is conducted in the context of a large-scale, theoretically driven model of adaptation for hunters and gatherers loosely based on aspects of Optimal Foraging Theory. In addition to 41ZV202, the approach relies on comparative data sets from Late Archaic and other Late Prehistoric sites from South and South-Central Texas to investigate shifts in subsistence, technology, and mobility across this broad region. At this time, discard decisions have not been made. However, all artifacts and associated samples collected and retained during this project, along with all project-associated documentation, are to be permanently curated at the CAR according to Texas Historical Commission guidelines

Non-traditional uses of maize: Biofuels, remediation and pharmaceuticals

© 2015 by Taylor & Francis Group, LLC. Traditionally, plants have been used for a variety of applications in addition to food and feed, including manufacture of industrial products, vaccines and pharmaceuticals. Maize has the potential to be used for numerous non-food purposes. Maize has been used extensively as an energy crop, to produce bioethanol both from grain as well as biomass. In addition, a wide variety of industrial products such as packing and insulating materials, chemicals, explosives, paint, insecticides, organic acids, solvents, antifreeze, etc. are made using maize products. Maize is also being used as a source of recombinant pharmaceutical products. The main advantages of using maize are that it is genetically well characterized, a well-established agricultural production infrastructure is available for its production, the technology for in vitro manipulation and gene transfer exists in maize, and it also is a fast-growing, high biomass plant. Maize has also been studied extensively for use in phytoremediation of various heavy metals

Aluminum-based drinking-water treatment residuals: a novel sorbent for perchlorate removal

Perchlorate contamination of aquifers and drinking-water supplies has led to stringent regulations in several states to reduce perchlorate concentrations in water at acceptable levels for human consumption. Several perchlorate treatment technologies exist, but there is significant cost associated with their use, and the majority of them are unable to degrade perchlorate to innocuous chloride. We propose the use of a novel sorbent for perchlorate, i.e. an aluminum-based drinking-water treatment residual (Al-WTR), which is a by-product of the drinking-water treatment process. Perchlorate sorption isotherms (23 ± 1 °C) showed that the greatest amount (65%) of perchlorate removed by the Al-WTR was observed with the lowest initial perchlorate load (10 mg L−1) after only 2 h of contact time. Increasing the contact time to 24 h, perchlorate removal increased from 65 to 76%. A significant correlation was observed between the amounts of perchlorate removed with evolved chloride in solution, suggesting degradation of perchlorate to chloride

Current trends and future directions in environmental geochemistry research

Increasing population growth and rapid industrialization with passing time have augmented the rate of deterioration of the environment, which is having a clear negative impact on human and ecological health. Although considerable research is now being undertaken in critical areas such as global change, environmental quality, and ecological protection, more collaborative, inter-disciplinary research is needed in order to ensure long-term environmental sustainability. A thorough understanding of the geochemistry of the earth's intrinsic processes is needed to develop a comprehensive, holistic model for the protection of the environment to ensure long-term sustainability in a global scale. This chapter briefly discusses some of the more salient current trends in environmental geochemistry research and a few of the many potential future directions of research in this area, often in close collaboration with experts in other scientific disciplines and policy makers geared towards maintaining earth system sustainability

Effects of incubation time and arsenic load on arsenic bioaccessibility in three Florida soils amended with sodium arsenate

The potential for human exposure to arsenic (As), a group A carcinogen, has increased tremendously due to the encroachment of suburban areas into former agricultural lands, where arsenical pesticides were used extensively prior to the 1990s. Soil ingestion is the no. 1 route of As exposure, attributable to incidental hand-to-mouth activities by children in playgrounds or house yards having As-contaminated soil. Previous studies have shown that As bioaccessibility in soils is mostly a function of their physicochemical properties. We selected three Florida soils covering a wide range in chemical properties, such as, Fe/Al hydroxides, organic matter, and Ca/Mg content, which are most likely to influence As bioavailability. The soils were amended with sodium arsenate pesticide at loads ranging from 45 to 450 mg As per kg, and subsequently incubated up to 12 months. The overall objectives of this study were to evaluate the effects of incubation time and As load on soil speciation, hence bioaccessibility of As. Results showed a reduction in the water-soluble, and plant-available (water+NH4Cl-extractable) As fractions of the three soils after four months of incubation, which remained unchanged up to 12 months. This reduction with time was accompanied by a concurrent increase in the NaOH-extractable As fraction, suggesting As sorption by amorphous Fe/Al hydroxides could decrease As bioaccessibility. The effect was most pronounced for the Pahokee Muck soil, which had the greatest amount of amorphous Fe/Al hydroxides (2000 mg kg−1) of all soils. Arsenic associated with the water- and plant-available As fractions is most bioaccessible as indicated by the significant (α=0.05) correlation between the water-soluble, plant-available, and the in-vitro bioaccessible As fraction in the soils. The NaOH-extractable As fraction was negatively correlated with the in-vitro bioaccessible As fraction, suggesting that the presence of Fe/Al hydroxides could decrease As lability in soils

Arsenic fractionation and bioaccessibility in two alkaline Texas soils incubated with sodium arsenate

Elevated arsenic (As) concentrations in urban soils with prolonged arsenical pesticide application history have increased the risk associated with accidental hand-to-mouth soil ingestion by children. Earlier work by the authors suggested that the conservative statement of 100% As bioaccessibility in soils was not valid for a set of acidic soils incubated with sodium arsenate. In this study, two alkaline Texas soils incubated with a commonly used As pesticide (sodium arsenate) were evaluated for their potential in reducing soil As bioaccessibility. The objective of this study was to evaluate the effects of incubation time and As load on soil As fractionation and bioaccessibility. Soils were subjected to a sequential As fractionation scheme, and bioaccessible As was quantified using an in vitro stomach phase test. Results showed a reduction in the water-soluble As fraction with incubation time (after 4 months), which remained unchanged after 12 months. This reduction with time was accompanied by an increase in the NaOH- and H2SO4-extractable As fractions, suggesting As sorption by amorphous Fe/Al hydroxides and/or Ca/Mg compounds, respectively. Organic/sulfides-bound As increased with incubation time after 12 months but not after 4 months of incubation. The aging effect was also observed with the amount of bioaccessible As at all As loads, showing significant positive correlations with the water-extractable and exchangeable As fractions. Bioaccessible As concentrations even after 12 months of incubation were not significantly reduced, suggesting that natural attenuation might prove inadequate to control As bioaccessibility in these alkaline soils