Henrybrooks5167

Pesticide concentrations were 2.58-3.66 μg/L much higher than antibiotics (8.6-47.6 ng/L). The results showed that MCs (ng/L) and DBPs (haloacetic acids, HAAs μg/L; N-nitrosodimethylamine, NDMA ng/L) were found to be in low detection frequencies. It was found that 51.1-74.6% of organic matters in source water were composed of molecular weight (MW) less then 1 kDa. The removal rates for the part of MW less then 1 kDa were only 11.7-12.3% through the conventional treatment processes, compared with higher removal rates of 23.5-28.5% by advanced treatment processes. Pesticides, antibiotics and MCs can be significantly removed by six drinking water treatment plants.Radioactive materials released during the two most serious nuclear accidents in history, at Chernobyl and Fukushima, caused exceptionally significant contamination and perturbations of the environment. Among them, this paper focuses on the effects related to the atmospheric electricity (AE). Measurements of the most significant disturbances in the values of various AE parameters recorded near ground level are reviewed and the corresponding results are jointly evaluated. The Chernobyl and Fukushima events caused changes in the AE parameters both after long-distance transport (Chernobyl) and short-distance transport including re-suspension (Fukushima). The data indicates that the electrical conductivity of the air is more sensitive to the presence of airborne radioactivity than the atmospheric electric potential gradient (PG). PG, on the other hand, can be monitored more easily and its variation also reflects the vertical redistribution of radionuclides in the air due to their transport, deposition, and re-suspension from the ground. A brief overview of studies on atmospheric transport and deposition of radioactive clouds is given to facilitate the importance of considering the AE measurements in these subjects, and to incorporate those studies in interpreting the results of AE measurements. The AE measurements are particularly important in studying microphysical effects of enhanced radioactivity in the air where no other distance monitoring method exists, both for fair weather conditions wet conditions.An innovative ammoniation-hydrothermal method of biochar production was developed for the adsorption of phenanthrene (PHE) from aqueous solutions in this paper. Phragmites australis (PA) was used to produce biochar in a hydrothermal kettle at 280 °C in muffle furnace using urea as an ammoniation reagent. selleck compound Characterizations were executed by scanning electron microscope (SEM), N2 adsorption/desorption isotherms, X-ray diffraction (XRD), elemental analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) to explore its morphological, physical, and chemical properties. Batch experiments of PHE adsorption were carried out to study the adsorption isotherms and kinetics. Quantum chemistry computational simulations were employed based on density functional theory (DFT) to establish and optimize adsorption configurations and analyze the biochar's structural effects on adsorption performance. Results showed that the ammoniation-hydrothermal method produced biochar with a higher surface area and a maximum equilibrium adsorption capacity of 1.97 mg/g. The adsorption fitted well with Freundlich isotherm model (R2 > 0.96) and Pseudo-second-order kinetic model (R2 > 0.82). Adsorption energy calculation revealed that the N functionalities, especially pyridine N in the N-doped biochar structure, exhibited stronger binding ability with PHE, which contributed most to the favorable adsorption ability of the ammoniation-hydrothermal biochar.Peroxymonosulfate (PMS) was employed as an activator of ozone (O3) to degrade non-steroidal anti-inflammatory drugs (NSAIDs) (aspirin (ASA) and phenacetin (PNT)) in study. The combination of PMS in O3 system promoted the O3 decomposition and NSAIDs removal significantly. O3 molecule, hydroxyl radical (OH) and sulfate radical (SO4-) were responsible for the removal of target pollutants in O3/PMS system. The second-rate constants between O3, OH and SO4- with ASA were determined to be 7.32, 4.18 × 109 and 3.46 × 108 M-1·s-1, and 37.3, 4.99 × 109 and 5.64 × 108 M-1·s-1 for PNT, respectively. The pattern of pollutant removal and contributions of oxidative species were fitted by experiments and two models. Nevertheless, the wide variety of two models suggested that a comprehensive model for O3/PMS based on a first-principles approach was not yet possible, due to the number of radicals and subsequent chain reaction, such as SO5- or O3-. In addition, the formation of five typical CX3R -type disinfection by products was evaluated from post‑chlorine tests and theoretically calculation by frontier electron density calculation. The calculated toxicity of typical CX3R -type DBPs was found to decrease with the increase of pH. The results of this study provide a basis for exploring the mechanism of pollutant degradation in O3 system.Grain and soil were sampled across a large part of Amhara, Ethiopia in a study motivated by prior evidence of selenium (Se) deficiency in the Region's population. The grain samples (teff, Eragrostis tef, and wheat, Triticum aestivum) were analysed for concentration of Se and the soils were analysed for various properties, including Se concentration measured in different extractants. Predictive models for concentration of Se in the respective grains were developed, and the predicted values, along with observed concentrations in the two grains were represented by a multivariate linear mixed model in which selected covariates, derived from remote sensor observations and a digital elevation model, were included as fixed effects. In all modelling steps the selection of predictors was done using false discovery rate control, to avoid over-fitting, and using an α-investment procedure to maximize the statistical power to detect significant relationships by ordering the tests in a sequence based on scientific understanding of the underlying processes likely to control Se concentration in grain. Cross-validation indicated that uncertainties in the empirical best linear unbiased predictions of the Se concentration in both grains were well-characterized by the prediction error variances obtained from the model. The predictions were displayed as maps, and their uncertainty was characterized by computing the probability that the true concentration of Se in grain would be such that a standard serving would not provide the recommended daily allowance of Se. The spatial variation of grain Se was substantial, concentrations in wheat and teff differed but showed the same broad spatial pattern. Such information could be used to target effective interventions to address Se deficiency, and the general procedure used for mapping could be applied to other micronutrients and crops in similar settings.In this study, dissolved organic carbon (DOC) data and optical properties (absorbance and fluorescence) of DOM, weekly collected in the Arno River for 2 years, are used to investigate the main processes determining DOM temporal dynamics in a small Mediterranean river, with torrential hydrology and medium-high human impact, and to quantify the contribution of this river to Med Sea carbon budget. A clear seasonal cycle of DOM, with DOC values ranging between 170 and 490 μM, was observed. Optical properties indicates that DOM quality in the river is different depending on the season; terrestrial humic-like substances prevail in winter, when discharge and floods are the main drivers of DOM concentration and quality, whereas autochthonous protein-like substances prevail in spring and summer, when biological processes dominate. Our results provide a robust estimate of the DOC flux to the Med Sea (9.6 · 109 g DOC yr-1) and of its range of variability (12.95 · 109-5.12 · 109 g DOC yr-1). The 80% of this flux was generally delivered during autumn/winter with significant amounts ascribed to single flood events (up to 26% in 2014). This study, by providing a rich dataset on water quantity and quality and by quantifying the importance of the hydrological regime on DOC transport, represents an important step toward a quantitative modeling of the Arno River.The Sanjiang Plain has the largest marsh wetland area in China. Since the 1950s its size has declined due to land development, between 1986 and 2016 nearly 6072 km2 (57.5% of the area) was lost due to farm land expansion. Since the "Wetland for Grain" project in 2003, efforts have been made to improve marsh area for animal habitat and ecological protection. A key management concern is prioritizing areas for wetland restoration in scientific planning and polices making. In this study, the natural wetland restoration potentials were evaluated based on land-use change trajectory, seed bank viability and watershed sustainability and restorability. The annual land use maps from 1986 to 2016 were reconstructed using CLUE-S model with land use maps in 1995, 2000, 2005, 2010 and 2016, which were interpreted from Landsat TM/ETM images. Seed bank viability was determined by field sampling in wetland and farm land with different reclamation years and germination in lab. Sub-catchment was chosen as sustainability analysis unit, which was quantified by the impacts of wetland on peak flow reduction. The watershed restorability was performed with the factors of wetland degradation degree, seed bank viability, and the percentage of wetland to watershed area (PWW) with different restoration years. The results indicated that reclaimed wetland with a time since last development (TLD) of less then 15 years had a higher recovery potential and accounted for 39.2% of the lost wetland. Seventeen sub-catchments with a total area of 2177 km2 of farmland could be planned for restoration, which could support more than half of the sub-catchments in the study area. Priority areas were identified for short-, mid- and long-term restoration planning. The results can support the scientific planning demands of various restoration goals in the study area, and provide a new method for wetland restoration.The compound 2-mercaptobenzothizaole (MBT) has been frequently detected in wastewater and surface water and is a potential threat to both aquatic organisms and human health (its mutagenic potential has been demonstrated). This study investigated the degradation routes of MBT in the anode of a microbial electrolysis cell (MEC) and the involved microbial communities. The results indicated that graphene-modified anodes promoted the presence of more enriched, developed, and specific communities compared to bare anodes. Moreover, consecutive additions of the OH substituent to the benzene ring of MBT were only detected in the reactor equipped with the graphene-treated electrode. Both phenomena, together with the application of an external voltage, may be related to the larger reduction of biotoxicity observed in the MEC equipped with graphene-modified anodes (46.2 eqtox∙m-3 to 27.9 eqtox∙m-3).As an essential section before final sludge disposal, sludge dewatering has currently been one of the focus issues. In this study, an innovative Fe2+/persulfate/tannic acid (TA) process was verified to further strengthen systemic efficacy on enhancing sludge dewaterability, compared with the conventional Fe2+/persulfate process. With the efficient TA/Fe2+ (molar ratio) of 0.25 added in Fe2+ (0.3 mmol/gTS (total solid))/persulfate (0.6 mmol/gTS) process, sludge dewaterability was enhanced remarkably. Capillary suction time, specific resistance to filtration, and water content of dewatered sludge cake were further reduced by 61.5%, 35.3%, and 6.4% than these in Fe2+/persulfate. Sludge supernatant viscosity was further reduced by 86.7% due to the more removal of extracellular polymeric substances (EPS). The secondary structure of EPS protein changed apparently and fluorescent components of EPS decreased distinctly. Sludge functional group contents were observed to be lower. TA effectually increased sludge particle size and heightened sludge flocculability, rendering the large and compact aggregations.