Singermcclanahan7775

Total removal of organic mercury in industrial wastewater is a crucially important task facing environmental pollution in the current world. Herein, we demonstrate the fabrication of Au-NiFe layered double hydroxide (LDH)/rGO nanocomposite as not only an efficient nanozyme with oxidase-like activity but also an efficient surface-enhanced Raman spectroscopy (SERS) substrate to determine organic mercury, with the minimum detection concentration as low as 1 × 10-8 M. According to the binding energy of X-Ray photoelectron spectrometer (XPS) and the free radicals of electron paramagnetic resonance (EPR) spectra, the mechanism of catalytic enhanced degradation is the production of Au-amalgam on Au surface, accelerating the electron transfer and the generation of O2•- radicals from oxygen molecules and •CH3 radicals from the methyl group in MeHg to participate the oxidase-like reaction. Furthermore, the Au-NiFe LDH/rGO nanocomposite is able to degrade and remove 99.9% of organic mercury in two hours without the secondary pollution by Hg2+. In addition, the material can be used for the multiple degradation-regeneration cycles in actual applications, which is significant in terms of the environmental and economic point of view. This work may open a new horizon for both highly sensitive detection and thorough degradation of organic mercury in environmental science and technology.The kinetics and mechanisms of the oxidation of Cr(III) in soil contaminated by unsaturated oils were investigated. Batch experiments were performed with unsaturated oils, namely, fish oil, hydrogenated lard oil, rapeseed oil, and caster oil. Impacts of environmental parameters, including temperature, soil pH, UV irradiation, oil content, and soil moisture content were examined. Results showed that oxidation of Cr(III) in oil-treated soils was accompanied by the formation of Cr(VI), which first increased and then decreased. Changes in the peroxide values of oils and the production of hexanal in the soil indicated that hydroperoxide was closely related to the formation of Cr(VI). tert-Butylhydroperoxide, as a model molecule of hydroperoxide, significantly enhanced the oxidation of Cr(III) in water. This result further showed that hydroperoxides were responsible for the oxidation of Cr(III). Native soil substances, such as organic matter, Fe(II), and microbes, and the decomposition products of hydroperoxides, such as aldehydes, could reduce Cr(VI). The change in Cr(VI) content in the soil resulted from the competition between the oxidation of Cr(III) and the reduction of Cr(VI). High temperature, high soil pH, UV irradiation, and low soil moisture content could facilitate the oxidation of Cr(III), which is of environmental significance.Catalytic ozonation was suggested to be effective for micropollutant removal during water treatment. However, research on organic byproduct formation from catalytic ozonation of real filtered water in water treatment plants was lacking. In this work, two synthesized catalysts, α-FeOOH and CeO2, were applied to catalyze ozonation of real filtered water at different ozone dosages, and the byproducts were quantified. Results showed that the α-FeOOH enhanced hydroxyl radical production, while the CeO2 did not. Both catalysts further reduced dissolved organic carbon (DOC) and UV254 of the filtered water during the catalytic oxidation processes. The O3/CeO2 improved the removal of low molecular weight compounds, especially the refractory compounds such as ketoacids and carboxylic acids, compared to ozonation alone. While the O3/α-FeOOH generated higher concentrations of carboxylic acids than that of ozonation. Thus, in light of DOC and low molecular weight compound reductions, CeO2 was the superior catalyst for micropollutant removal in real filtered water.Chromium sludge is a hazardous solid waste which cannot be effectively treated but only piled up and abandoned, causing serious environment pollution and resource wasting. This work proposes an effective novel process to separately recover all resources in chromium sludge via a sustainable way. The obtained acid solving liquid from chromium sludge is desiliconized by cationic flocculant (PCAM) to induce coprecipitation of polysilicate gel and PCAM, which mixture is calcinated to generate the product of white carbon black in purity of 94.35% with a recovery of 92.58%. After desiliconization, V in the solving liquid is selectively extracted by microemulsion (ME), which is recovered as V2O5 in purity of 99.34% with a recovery of 95.53% by the subsequent procedure of stripping-precipitation-calcination. The Fe3+ in raffinate is reduced to Fe2+ cations by Na2SO3, and is then recovered by H2C2O4 precipitation to generate the FeC2O4 product in purity of 99.12% with a recovery of 98.25%. Cr3+ cations in residual solution are recovered by alkaline precipitation and calcination to generate the Cr2O3 product in purity of 98.25% with a recovery of 92.68%. This work provides fresh penetrations into the synchronous detoxification, resource recovery and value-added utilization of hazardous industrial solid wastes.Plastic pollution is a growing problem, not at least in areas where poor waste management results in direct pollution of coastal zones, such as South Asia and regions in Africa. In addition to the effect on ecosystems and their related services, plastic pollution may also affect human health indirectly as vectors for infectious disease. As plastic offers a suitable surface for the attachment of biofilm forming bacteria, it may contribute to disease outbreaks and antimicrobial resistance. To investigate the role of plastic litter as potential vectors for pathogenic bacteria, we collected plastic litter from four rural sites in Zanzibar, and isolated adhered bacteria. Isolates were short-read sequenced for further molecular analysis. This revealed that collected plastic litter was associated with diverse bacterial species, including human pathogens Citrobacter freundii, Klebsiella pneumoniae and Vibrio cholerae. Furthermore, most isolates were found to be multidrug resistant. Our findings confirm that plastic litter, serve as novel reservoir for human multidrug resistant pathogenic bacteria that combined with poor sanitation and waste handling, may lead to transmission of infectious diseases and antimicrobial resistance. These findings add a new level to the environmental challenges with plastic pollution; the potential health risk associated with exposure to plastic litter.Antibiotics commonly exist in municipal, livestock and industrial wastewaters. However, the response of key microbiota performance in wastewater treatment plants to antibiotic exposure lacks systematic research. In this study, the short-term acute stress of four commonly used antibiotics (sulfamethoxazole, chlortetracycline, ciprofloxacin, and amoxicillin) on microbial denitrification performance was systematically investigated. All tested antibiotics exhibited the inhibitory effects in varying degrees by repeated addition for six cycles. The nitrate removal efficiencies (NrE) decreased to 7.98-26.80%, accompanied by the significant decrease of the expressed narG gene, by exposure to sulfamethoxazole, chlortetracycline or amoxicillin. Nitrite reduction was inhibited more severely than nitrate reduction, which was further verified by the low- or non-expressed nirS and nosZ genes. Furthermore, a higher antibiotic concentration made stronger inhibitory effect. Except for chlortetracycline, 2.09-6.80 times decrease of k value was commonly observed as concentration increased from 10 to 50 or 100 mg L-1. Even in a short period (24 h), antibiotics largely decreased the abundance of the dominant denitrifying bacterial genera (Thauera, Comamonas, etc.), while, some unclassified populations (Labrenzia, Longilinea, etc.) were enriched. This study provides theoretical researches on the microbial denitrification behaviors influenced by exposure to different antibiotics.Ultrasound imaging is a non-invasive technique to assess organ function. Its potential application in rodents to evaluate respiratory function remains poorly investigated. We aimed to assess and validate ultrasound technique in rats to analyze inspiratory and expiratory muscles. We measured respiratory parameters to provide normal eupneic values. Histological studies and plethysmography were used to validate the technique and assess the physiological implications. A linear relationship was observed between ultrasound and histological data for diaphragm and rectus abdominis (RA) measurement. The tidal volume was significantly correlated with the right + left RA area (r = 0.76, p less then 0.001), and the rapid shallow breathing index was significantly and inversely correlated with the right + left RA area (r=-0.53, p less then 0.05). In the supine position, the right and left diaphragm expiratory thickness were not associated with tidal volume obtained in the physiological position. Ultrasound imaging is highly accurate and reproducible to assess and follow up diaphragm and RA structure and function in rats.Forced mid-expiratory flow (i.e., isoFEF25-75) may increase with a short-acting β2-agonist in nonasthmatic children without bronchodilator responsiveness. This could also increase estimated ventilatory capacity along mid-expiration (V̇Ecap25-75), especially in vulnerable children with obesity who exhibit altered breathing mechanics. We estimated V̇Ecap25-75 pre- and post-albuterol treatment in 8-12yo children without (n = 28) and with (n = 46) obesity. A two-way ANOVA was performed to determine effects of an inhaled bronchodilator (pre-post) and obesity (group) on isoFEF25-75 and V̇Ecap25-75. There was no group by bronchodilator interaction or main group effect on outcome variables. However, a significant main effect of the bronchodilator was detected in spirometry parameters, including a substantial increase in isoFEF25-75 (17.1 ± 18.0 %) and only a slight (non-clinical) but significant increase in FEV1 (2.4 ± 4.3 %). V̇Ecap25-75 significantly increased with albuterol (+11.7 ± 10.6 L/min; +15.8 ± 13.9 %). These findings imply potentially important increases in ventilatory reserve with a bronchodilator in nonasthmatic children without and with obesity, which could potentially influence respiratory function at rest and during exercise.microRNAs have evolved as important regulators of multiple biological pathways essential for bone homeostasis, and microRNA research has furthered our understanding of the mechanisms underlying bone health and disease. This knowledge, together with the finding that active or passive release of microRNAs from cells into the extracellular space enables minimal-invasive detection in biofluids (circulating miRNAs), motivated researchers to explore microRNAs as biomarkers in several pathologic conditions, including bone diseases. Thus, exploratory studies in cohorts representing different types of bone diseases have been performed. In this review, we first summarize important molecular basics of microRNA function and release and provide recommendations for best (pre-)analytical practices and documentation standards for circulating microRNA research required for generating high quality data and ensuring reproducibility of results. Secondly, we review how the genesis of bone-derived circulating microRNAs via release from osteoblasts and osteoclasts could contribute to the communication between these cells.