Charlesbrowning5605

The trace element analysis and bioassay results indicated site-specific differences between foraging populations. In particular, turtles from Moreton Bay, a heavily populated coastal embayment, had pronounced cytotoxicity and oxidative stress from organic blood extracts, and elevated concentrations of Cs, Ag, and Zn relative to the other sites. Incorporating traditional chemical analysis with novel effects-based methods can provide a comprehensive assessment of chemical risk in sea turtle populations, contributing to the conservation and management of these threatened species.Natural chlorate (ClO3-) is widely distributed in terrestrial and extraterrestrial environments. To improve understanding of the origins and distribution of ClO3-, we developed and tested methods to determine the multi-dimensional isotopic compositions (δ18O, Δ17O, δ37Cl, 36Cl/Cl) of ClO3- and then applied the methods to samples of natural nitrate-rich caliche-type salt deposits in the Atacama Desert, Chile, and Death Valley, USA. Tests with reagents and artificial mixed samples indicate stable-isotope ratios were minimally affected by the purification processes. Chlorate extracted from Atacama samples had δ18O = +7.0 to +11.1‰, Δ17O = +5.7 to +6.4‰, δ37Cl = -1.4 to +1.3‰, and 36Cl/Cl = 48 × 10-15 to 104 × 10-15. Chlorate from Death Valley samples had δ18O = -6.9 to +1.6‰, Δ17O = +0.4 to +2.6‰, δ37Cl = +0.8 to +1.0‰, and 36Cl/Cl = 14 × 10-15 to 44 × 10-15. Positive Δ17O values of natural ClO3- indicate that its production involved reaction with O3, while its Cl isotopic composition is consistent with a tropospheric or near-surface source of Cl. The Δ17O and δ18O values of natural ClO3- are positively correlated, as are those of ClO4- and NO3- from the same localities, possibly indicating variation in the relative contributions of O3 as a source of O in the formation of the oxyanions. PJ34 Additional isotopic analyses of ClO3- could provide stronger constraints on its production mechanisms and/or post-formational alterations, with applications for environmental forensics, global biogeochemical cycling of Cl, and the origins of oxyanions detected on Mars.This investigation explores the efficacy of employing ultrasonic cavitation and coupling it with advanced oxidation processes (hydrogen peroxide and Fenton's reagent) for reducing the levels of total ammonia nitrogen in fish pond water containing Tilapia fishes. Ultrasonic cavitation is a phenomenon where the formation, growth and collapse of vaporous bubbles occur in a liquid medium producing highly reactive free radicals. Ultrasonic probe system (20 kHz with 750 W and 1000 W) was used to induce cavitation. Besides, to intensify the process, ultrasonic cavitation was coupled with hydrogen peroxide and Fenton's reagent. Using SERA colour indicator test kits, the levels of ammonium, nitrite and carbonate hardness were measured. The results obtained from this study clearly show that the advanced oxidation processes are more efficient in reducing the ammonium and nitrite levels in fish pond water than using ultrasound alone. The pH and carbonate hardness levels were not affected significantly by ultrasonic cavitation. The optimal treatment time and ultrasound power to treat the water samples were also established. Energy efficiency and cost analysis of this treatment have also been presented, indicating that ultrasonic cavitation coupled with hydrogen peroxide appears to be a promising technique for reducing total ammonia nitrogen levels in the fish pond water.The removal of organic pollutants from water environments is a challenging problem. Fe-based BC (Fe-BC) composites are promising catalysts for generating reactive oxygen species (ROS) for environmental remediation considering their low costs and excellent physicochemical surface characteristics. The synthesis methods, properties, applications, and the mechanism of Fe-BC for removing pollutants are reviewed. Various methods have been used to prepare Fe-BC composites, and the synthetic methods and conditions used affect the properties of the Fe-BC material, thereby influencing its pollutant removal performance. The mechanisms of pollutant removal by Fe-BC are intricate and include adsorption, degradation and reduction. Fe loading on BC could improve the performance of BC by affecting its surface area, surface functional groups and electron transfer rate. Moreover, research gaps and uncertainties that exist in the use of Fe-BC were identified. Finally, the problems that need to be solved to make Fe-BC suitable for future applications are described.Platinized TiO2 (Pt/TiO2) as a benchmark photocatalyst shows superior photocatalytic performance in environmental remediation. In order to reduce the cost of photocatalyst for practical use, a series of cooper loaded TiO2 (Cu/TiO2) photocatalysts were prepared by photoreduction method and compared with pure TiO2 and Pt/TiO2 in terms of overall ammonia conversion efficiency and selective oxidation. The as-prepared Cu/TiO2 samples were characterized and analyzed by physicochemical instrumental measurements. The results show that about 60% Cu2+ ions in suspension can be photodeposited onto the surface of TiO2 under UV light irradiation, and is mainly composed by a mixture of Cu/Cu+. The Cu/P25 (0.3 wt% Cu) sample was screened out as the optimal photocatalyst, via photoilluminance spectra analysis and photocatalytic oxidation of ammonia. It shows even better performance compared to Pt/TiO2 in the oxidation of high concentration of ammonia, due to the strong coordination effect by Cu(NH3)n complex formation. Through Electron Spin Resonance (EPR) analysis, and free radical suppression experiments, the active oxidative species account for ammonia oxidation and selective product generation were analyzed, and the possible reaction mechanisms involving photocatalytic ammonia conversion were proposed. ●OH has been identified as the main oxidant that affects the removal efficiency of ammonia nitrogen, whereas O2●- mainly affects the production of N2 and h+ is mainly responsible for the production of NO3-. These results indicate that Cu/TiO2 could be used as a low-cost and efficient photocatalyst in pretreatment process for conversion of high concentration of ammonia in wastewater.