Zobrazení zdroje stránky Alvarezmahler7406

The reaction of pyrene with PM produced a lower soil pH condition, which was conductive to the transport of Cu, and the existence of Cu promoted the migration of PM. The coexistence of Cu and pyrene favored the removal efficiency of the pollutants, and 92.8% of Cu and 70.7% of pyrene were removed after 15 d EK treatment. Thus, EK + acidic PM with regularly supplement of oxidant is appropriate to achieve complete mass depletion of heavy metals and PAHs, especially in low buffered soils.It is unclear how biochar can affect P availability in soil, especially in field under continuous application. In this study, a field experiment was conducted to study the effect of 2-years application of biochar on P availability, P fractionation, P sorption and release in a clay soil. The biochar in this study was produced from rice straw through pyrolysis at 700°C. As compared with no fertilizer treatment (CK) and chemical fertilizer treatment (CF), the biochar application with chemical fertilizer treatment (BCF) significantly increased total P and available P content in soil. And BCF treatment significantly increased resin P, NaHCO3-extracted P, Fe/Al-Po and HCl-extracted P but decreased Fe/Al-Pi and residual P as compared with CF treatment. Surprisingly, BCF treatment showed higher sorption capacity and release capacity of soil P than that of CF treatment. These results imply that continuous application of biochar for 2-years in field may adsorbed P through physical sorption rather than chemical reaction and then improve P availability in soil.Mechanistic insight into protein binding by poly- and perfluoroalkyl substances (PFASs) is critical to understanding how PFASs distribute and accumulate within the body and to developing predictive models within and across classes of PFASs. Fluorine nuclear magnetic resonance spectroscopy (19F NMR) has proven to be a powerful, yet underutilized tool to study PFAS binding; chemical shifts of each fluorine group reflect the local environment along the length of the PFAS molecule. Using bovine serum albumin (BSA), we report dissociation constants, Kd, for four common PFASs well below reported critical micelle concentrations (CMCs) - perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) - as a function of temperature in phosphate buffered saline. Kd values were determined based on the difluoroethyl group adjacent to the anionic headgroups and the terminal trifluoromethyl groups. Our results indicate that the hydrophobic tails exhibit greater binding affinity relative to the headgroup, and that the binding affinities are generally consistent with previous results showing that greater PFAS hydrophobicity leads to greater protein binding. However, the binding mechanism was dominated by entropic hydrophobic interactions attributed to desolvation of the PFAS tails within the hydrophobic cavities of the protein and on the surface of the protein. In addition, PFNA appears to form hemimicelles on the protein surfaces below reported CMC values. This work provides a renewed approach to utilizing 19F NMR for PFAS-protein binding studies and a new perspective on the role of solvent entropy.Distribution and elimination of petroleum products can be predicted in aerobic wastewater treatment plants (WWTPs) using models such as multimedia fate model SimpleTreat. An advantage of the SimpleTreat model is that it only requires a few basic properties of a chemical in wastewater to calculate partitioning, biodegradation and ultimately emissions to air, surface water and produced sludge. The SimpleTreat model structure reflects a WWTP scheme. However, refinery WWTPs typically incorporate more advanced treatment processes such as dissolved air flotation (DAF), a process that clarifies wastewaters by the removal of suspended matter such as oil or solids. The objective of this work was to develop a WWTP removal model that includes DAF treatment. To understand how including a DAF in the model affects the predicted concentrations of petroleum constituents in effluent, we replaced the primary sedimentation module in SimpleTreat with a module simulating DAF. Subsequently, we compared results from the WWTP-DAF model with results obtained with the original SimpleTreat model for a library of over 1500 representative hydrocarbon constituents. The increased air-water exchange in a WWTP-DAF unit resulted in higher predicted removal of volatile constituents. Predicted removal with DAF was on average 17% larger than removal with primary sedimentation. [https://www.selleckchem.com/products/dnqx.html https://www.selleckchem.com/products/dnqx.html] We compared modelled results with measured removal data from the literature, which supported that this model refinement continues to improve the technical basis of assessment of petroleum products.The invasive weed, Ipomoea staphylina (IS) with cow dung (CD) and mushroom spent straw (MS) in four different combinations (ISCDMS), V1 (110), V2 (211), V3 (101) and V4 (111) were pre-decomposed for 21 days followed by 50 days vermicomposting using Eudrilus eugeniae in triplicates in order to alleviate and to utilize the weed biomass in an environment-friendly manner. The contents of organic matter, organic carbon, cellulose, lignin, C/N and C/P ratios showed a decrease, while electrical conductivity, total NPK, calcium, sodium, and nitrate-nitrogen showed a significant increase in vermicompost over control. Water-soluble organic carbon to organic nitrogen ratio and C/N ratio in V1 (0.52 and 17.55) and V4 (0.43 and 16.56), respectively, were in conformity with the maturity of vermicomposts. Scanning electron micrographs of the end products clearly showed more fragmented, fine, and porous particles in vermicompost. Copper, chromium, cadmium, lead, and zinc in vermicomposts were below the permissible limits. Dehydrogenase, acid phosphatase, alkaline phosphatase, cellulase, and protease activities were significantly higher in V4 than other treatments, implying the role of MS and CD addition during vermicomposting. Though V3 combination supported worm biomass, V4 combination was found to favor the fecundity of Eudrilus eugeniae. Results reveal that 111 combination of SI + CD + MS (V4) is suitable for utilizing the weed biomass for vermicompost production and nutrient recovery. From the biomass of environmentally problematic weed, Ipomoea staphylina, nutrient-rich vermicompost can be produced through vermitechnology for sustainable environmental management and agriculture.Naphthalene is the simplest representative of polycyclic aromatic hydrocarbons (PAHs). It is detected as major pollutant in the different compartments of the environment. This compound is considered by the international agency for research on cancer (IARC), the specialized cancer agency of the World Health Organisation (WHO), as a possible carcinogenic (group 2B) since 2002, mainly based on studies on chronic inhalation in rodent by the national toxicology program of the U.S. department of health and human services. In humans, its main metabolites correspond to derivatives substituted in position and 1 and 2 as 1,2-naphthoquinone (1,2-NphQ). Based on previous studies, 1,2-NphQ is supposed to react with DNA to form mostly depurinating adducts, a possible initiating step of carcinogenicity. To confirm this potentiality, adducts were synthetized by the reaction of 1,2-NphQ with 2'-deoxyguanosine (2'-dG) in N,N-dimethylformamide (DMF), water and calf thymus DNA. 2'-dG adducts were analyzed by 32P post-labelling, HPLC with ultra-violet detection and ultra-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). We found stable DNA adducts detected in DNA. We proposed a formation mechanism by a 1,4-Michael addition with 2'-dG. Adducts with 2'-deoxyxanthosine are formed after a spontaneous deamination of 2'-dG. These adducts are good candidates as biomarkers allowing evaluation of exposure to naphthalene and its derivatives in the development of pathologies such as cancer.The river-riparian interface plays an important role in removal of nitrogen pollution. Many revetments have been built in urban riparian zones, which has affected soil denitrification function of river-riparian interface. However, the impacts of revetments on denitrifying communities of soil in the river-riparian interface are still unclear. In this study, in the case of eliminating the influence of plants, three modes of revetments (No Revetments (NR), Impervious Masonry Revetments (IR), and Permeable Concrete Imitation Pile Revetments (PR)) were employed to determine the influence of revetments on denitrifying communities of soil among three distances from revetments (1.0, 0.6 and 0.3 m). It was shown in comparison with IR and NR, PR promoted the abundance, diversity and relative abundance of major strains in nirS and nirK denitrifying bacteria (P less then 0.05), but these effects decreased as distances increased. Compared with the IR (2.95 ± 1.15 × 105 copies g-1) and NR (4.13 ± 2.14 × 105 copies g-1), abundances of nirK denitrifying bacteria adjacent to PR (6.19 ± 1.89 × 105 copies g-1) were significantly higher (P less then 0.05). Rubrivivax and Bradyrhizobium were the dominant bacterial genera, accounting for 16.02-23.94% and 29.25%-38.25% of nirS- and nirK- denitrifying bacteria, respectively. SOC and nitrogen availability were the primary factors which influence the gene richness of nirK and nirS, while soil bulk density, sand content and WFPS as the major elements were impacting compositions of nirK and nirS communities. The results will improve the comprehension of theoretical process of denitrification affected by revetment types.Environmental exposure to pesticides increases the risk of neurotoxicity and neurodegenerative diseases. The mechanism of pesticide-induced toxicity is attributed to the increased reactive oxygen species, mitochondrial dysfunction, inhibition of key cellular enzymes and accelerated pathogenic protein aggregation. The structural basis of pesticide-protein interaction is limited to pathogenic proteins such as α-synuclein, Tau and amyloid-beta. However, the effect of pesticides on metabolic proteins is still unexplored. Here, we used rotenone and chlorpyrifos to understand the interaction of these pesticides with a metabolic protein, malate dehydrogenase (MDH) and the consequent pesticide-induced cytotoxicity. We found that rotenone and chlorpyrifos strongly bind to MDH, interferes with protein folding and triggers alteration in its secondary structure. link2 Both pesticides showed high binding affinities for MDH as observed by NMR and LCMS. Rotenone and chlorpyrifos induced structural alterations during MDH refolding resulting in the formation of cytotoxic conformers that generated oxidative stress and reduced cell viability. Our findings suggest that pesticides, in general, interact with proteins resulting in the formation of cytotoxic conformers that may have implications in neurotoxicity and neurodegenerative diseases.Pomegranate peel, a major waste from the food processing industries containing biologically active compounds, could be converted into value-added products having medicinal properties. link3 Present study deals with the ultrasound-assisted surfactant, namely dimethyl sulfoxide (DMSO) aided polyphenolics extraction from pomegranate peel waste using double distilled water (DDW) as a solvent. Maximum total yield of extraction and total polyphenolic content (TPC) were found respectively to be 43.58 ± 1.0 and 49.55 ± 0.8%, at optimized sonication parameters viz. temperature 50 °C, power density 1.2 W/mL and time 40 min followed by surfactant aided extraction under optimum conditions 0.6% DMSO, 50 °C and 150 rpm for 90 min. Kinetic models were developed to determine the polyphenolics concentration and validated. GC-MS analysis of the extract revealed 22 phenolic compounds. Thus, the acquired results have ensured the significance of ultrasound pre-treated surfactant aided extraction of polyphenolic compounds and this process can be developed for commercial production.