Chancheek3487

Increased expression of the stress response biomarkers was observed following DBE-DBCH exposure. In addition, DBE-DBCH diastereomers also altered the swimming behavior of Daphnia magna. The present study demonstrates that DBE-DBCH cause multiple deleterious effects on Daphnia magna, including effects on reproduction and hormonal systems. These endocrine disrupting effects are in agreement with effects observed on vertebrates. Furthermore, as is the case in vertebrates, DBE-DBCH γδ exerted stronger effects than DBE-DBCH αβ on Daphnia magna. This indicate that DBE-DBCH γδ has properties making it more toxic to all so far studied animals than DBE-DBCH αβ.Presently, graphenic nanomaterials are being studied as candidates for wastewater pollutant removal. In this study, two graphite oxides produced from natural graphite with different grain sizes (325 and 10 mesh), their respective reduced graphene oxides and one reduced graphene oxide with nitrogen functional groups were synthesized and tested to remove a surfactant model substrate, Triton X-100, from an aqueous solution. Kinetic experiments were carried out and adjusted to pseudo-first order equation, pseudo-second order equation, Elovich, Chain-Clayton and intra-particle diffusion models. Reduced graphene oxides displayed an instantaneous adsorption due to their accessible and hydrophobic surfaces, while graphite oxides hindered the TX100 adsorption rate due to their highly superficial oxygen content. Results from the adsorption isotherms showed that the Sips model perfectly described the TX100 adsorption behavior of these materials. Higher adsorption capacities were developed with reduced graphene oxides, being maximum for the material produced from the lower graphite grain size (qe = 3.55·10-6 mol/m2), which could be explained by a higher surface area (600 m2/g), a lower amount of superficial oxygen (O/C = 0.04) and a more defected structure (ID/IG = 0.85). Additionally, three commercial high surface area graphites in the range of 100-500 m2/g were evaluated for comparison purposes. In this case, better adsorption results were obtained with a more graphitic material, HSAG100 (qe = 1.72·10-6 mol/m2). However, the best experimental results of this study were obtained using synthesized graphenic materials.This paper aims to study the spatial and temporal patterns of selected agricultural runoff, specifically in terms of glyphosate, nitrate, and ammonia in bottom water, as well as their possible sources, within an active cockle farming area in Bagan Pasir, Perak, Malaysia. Samples were taken along the cockle farming area from March to November 2019. Glyphosate was analyzed using HPLC with both extraction and derivatization methods using 9-fluorenyl-methyl chloroformate (FMOC-Cl), while nitrate and ammonia levels were determined using the standard Hach method. Generally, glyphosate, nitrate, and ammonia were present within the study site with the average concentration of 37.44 ± 12.27 μg/l, 1.65 ± 0.52 mg/l, and 0.37 ± 0.19 mg/l, respectively. The results suggest that glyphosate and nitrate might be derived from an inland source, while a uniform and low level of ammonia suggested might originate from lithogenic origins. Continuous monitoring remains encouraged.Water quality of the Great Barrier Reef (GBR) is determined by a range of natural and anthropogenic drivers that are resolved in the eReefs coupled hydrodynamic - biogeochemical marine model forced by a process-based catchment model, GBR Dynamic SedNet. Model simulations presented here quantify the impact of anthropogenic catchment loads of sediments and nutrients on a range of marine water quality variables. Simulations of 2011-2018 show that reduction of anthropogenic catchment loads results in improved water quality, especially within river plumes. Within the 16 resolved river plumes, anthropogenic loads increased chlorophyll concentration by 0.10 (0.02-0.25) mg Chl m-3. Reductions of anthropogenic loads following proposed Reef 2050 Water Quality Improvement Plan targets reduced chlorophyll concentration in the plumes by 0.04 (0.01-0.10) mg Chl m-3. Our simulations demonstrate the impact of anthropogenic loads on GBR water quality and quantify the benefits of improved catchment management.

Long-term surface NO

data are essential for retrospective policy evaluation and chronic human exposure assessment. In the absence of NO

observations for Mainland China before 2013, training a model with 2013-2018 data to make predictions for 2005-2012 (back-extrapolation) could cause substantial estimation bias due to concept drift.

This study aims to correct the estimation bias in order to reconstruct the spatiotemporal distribution of daily surface NO

levels across China during 2005-2018.

On the basis of ground- and satellite-based data, we proposed the robust back-extrapolation with a random forest (RBE-RF) to simulate the surface NO

through intermediate modeling of the scaling factors. For comparison purposes, we also employed a random forest (Base-RF), as a representative of the commonly used approach, to directly model the surface NO

levels.

The validation against Taiwan's NO

observations during 2005-2012 showed that RBE-RF adequately corrected the substantial underestimation by Basebtained a full-coverage dataset of daily surface NO2 across China during 2005-2018, which is valuable for environmental management and epidemiological research.Freshwater ecosystems are responsible for an important part of the methane (CH4) emissions which are likely to change with global warming. This study aims to evaluate temperature-induced (from 5 to 20 °C) changes on microbial community structure and methanogenic pathways in five sub-Antarctic lake sediments from Magallanes strait to Cape Horn, Chile. We combined in situ CH4 flux measurements, CH4 production rates (MPRs), gene abundance quantification and microbial community structure analysis (metabarcoding of the 16S rRNA gene). TNO155 Under unamended conditions, a temperature increase of 5 °C doubled MPR while microbial community structure was not affected. Stimulation of methanogenesis by methanogenic precursors as acetate and H2/CO2, resulted in an increase of MPRs up to 127-fold and 19-fold, respectively, as well as an enrichment of mcrA-carriers strikingly stronger under acetate amendment. At low temperatures, H2/CO2-derived MPRs were considerably lower (down to 160-fold lower) than the acetate-derived MPRs, but the contribution of hydrogenotrophic methanogenesis increased with temperature.