Notes

Uses of Up-Flow Anaerobic Debris Blanket (UASB) and Qualities of their Microbe Community: A Review of Bibliometric Trend and up to date Studies.
Calcareous soil has a strong buffering capacity for neutralizing acid and stabilizing cadmium (Cd) because of the high calcium carbonate (CaCO3) content. However, it is not clear whether the buffering capacity of calcareous soil can be maintained after long-term wastewater irrigation. We selected a typical area in western China that has been irrigated with wastewater for over 50 years to study the temporal changes of soil properties and their effects on Cd uptake by wheat. The results showed that compared with the background level before the 1960s, the soil pH and CaCO3 content in 2018 were lower by 0.80 units and 35%, respectively, while the soil organic matter (SOM) content, Olsen phosphorus (P) content, and soil total Cd content in 2018 increased by 1.54, 13.05, and 164 times, respectively. Due to the significant decrease in the soil pH and CaCO3, the high load of soil total Cd and electrical conductivity, the low soil clay content, and the coupling of SOM with soil nitrogen and P, the input Cd was activated. Furthermore, the activated Cd was effectively taken up by wheat roots and transported to grains with the assistance of dissolved organic carbon. Our results highlight that long-term wastewater irrigation caused irreversible damage to soil buffering capacity, resulting in the Cd activation and the enhancement of Cd uptake by wheat.Recently, the exposure of nanoplastics (NPs) in the environment has received extensive attention. Research concerning their fate and transport in the aquatic environment is very important and urgent. In this study, the influence of two sources of natural organic matter (NOM) on the behaviour of NPs were investigated in view of the complexity of NOM. Humic acid (HA), Suwannee River humic acid (SRHA) and Upper Mississippi River NOM (MRNOM) were chosen to represent pedogenic NOM, while bovine serum albumin (BSA) was on behalf of aquagenic NOM. The results showed that NOM could reduce the aggregation and sedimentation of NPs, exhibiting excellent stabilization effect. The stability effect was affected by the concentrations and the sources of NOMs. For pedogenic NOMs, the stabilization effect was caused by adsorption modes with different microscopic morphologies through specific functional groups, while it was induced by the mode of steric stabilization in the presence of BSA. Spectroscopic method and micromorphology study further provided a new insight into exploring the possible mechanism of the interaction between NPs and NOMs.Seawater flue gas desulfurization (SFGD) has shown great effectiveness in the controlling of sulfur dioxide (SO2) emission and the removing of mercury (Hg) from flue gases of coal-fired power plants. Some problems pertaining to SFGD for Hg control, however, remain to be solved (1) environmental impact from the discharge of Hg-containing seawater to the ocean, and (2) re-emission of gaseous Hg from the aeration tank to the atmosphere. This study synthesizes the copper/sulfur co-impregnated activated carbon (Cu-S-AC) to simultaneously capture aqueous Hg(II) and inhibit gaseous Hg0 re-emission from actual SFGD wastewater. Cu-S-AC exhibited greater Hg(II) adsorption than both raw activated carbon (AC) and sulfur-impregnated activated carbon (S-AC) at an initial Hg(II) concentration of higher than 8000 ng/L. The Hg(II) adsorption of Cu-S-AC was slightly greater at pH 7 and 8 than that under acidic conditions. The Hg(II) adsorption was well-fitted with both linear and Freundlich isotherms. The results of thermodynamic analyses veiled the endothermic and spontaneous adsorption of Hg(II) on Cu-S-AC. In addition, the pseudo-second-order equation provided the best correlation coefficient for the Hg(II) adsorption on Cu-S-AC. Notably, the increases of pH and temperature increased the Hg0 re-emission. Nevertheless, Cu-S-AC addition significantly inhibited the Hg0 re-emission (92%) from SFGD wastewater.In this work, the performance of the atmospheric pressure chemical ionization (APCI) and photoionization (APPI) was assessed to develop a new selective and sensitive gas chromatography-high resolution mass spectrometry (GC-HRMS) method for the determination of polychlorinated naphthalenes (PCNs) in sediment samples. The capability of both APCI and APPI sources for the ionization of PCNs was investigated, showing the formation of the molecular ion and the [M‒Cl+O]‒ ion in positive and negative ion modes, respectively. Positive ion APCI provided high responses using high corona ion current, while the use of high vapour pressure dopant-solvents, such as toluene in positive mode and diethyl ether in the negative mode, was required to achieve high ionization efficiencies in APPI. The performance of the two API sources in the PCN determination by GC-HRMS were compared and the best results were achieved using the GC-APPI(+)-HRMS (Orbitrap) system. The GC-APPI(+)-HRMS (Orbitrap) method was applied to the characterization of Halowax mixtures and the analysis of marine sediments collected near to the coastal area of Barcelona (NE, Spain), demonstrating a great detection capability with low method limits of detection (0.2-1.6 pg g-1 dry weight), good precision (RSD less then 15%) and trueness (relative error less then 13%). Total PCN concentrations ranged from 0.35 to 5.0 ng g-1 dry weight and the presence of related compounds, such as polychlorinated biphenyls (PCBs), was also detected by combining positive and negative ion modes, providing complementary information to better monitor of all PCN congener groups. The results presented here show the feasibility of the GC-APPI-HRMS method for the suitable determination of PCNs.Thiacloprid is a neonicotinoid insecticide used to control sucking and chewing insects of fruits and vegetables. Hydrolysis, photolysis of thiacloprid in aqueous solutions, and soil degradation of three typical types of soil in China were studied. UHPLC-QTOF/MS was used to acquire high-resolution mass spectrometry information of thiacloprid's degradation products in water and soil samples, and the UNIFI platform with integrated data processing function was used to find and identify degradation products. The degradation kinetics of thiacloprid was determined. Six transformation products (M271, M287, M269, M295, M279, M267) were found after the data processing workflow in the UNIFI platform by using the raw MSE data. The structure of putative transformation products can be inferred based on the accurate mass of fragment ions and the automated spectral interpretation tools in the UNIFI platform. The structure of M271 was validated to be thiacloprid amide by comparing the ESI-MS2 fragment ions in soil samples and thiacloprid amide standard. The TrendPlot function of UNIFI was used to demonstrate the kinetics of the transformation products. Reduction, hydrolysis, oxidation are the main reactions of thiacloprid in three tested soil in China and buffer solutions. This study provided a reference for the rapid identification of the transformation products of other pesticides in specific environmental conditions.Humification is greatly enhanced by metallic oxides in nature, and the related products are critical to various environmental processes. Metabolism activator However, little is known about the interaction between metallic oxides and oxygen in promoting the oxidative polymerization of small organic molecules during the humification process. The synthesis of humic-like acids (HLAs) with MnO2 was performed in the presence and absence of oxygen, and the influence of oxygen and MnO2 on the composition evolution of amino-phenolic HLAs was illustrated. The results of ultraviolet-visible (UV-Vis) spectra of reaction mixtures associated with two-dimensional correlation spectroscopy (2D-COS) combined with the XPS spectra of N 1s content changes in HLAs demonstrated that MnO2 induced pyrrole-type nitrogen formation and enhanced darkening. Furthermore, MnO2 mainly acted as a catalyst, and oxygen activated the regeneration of MnO2 by oxidizing free manganese ions, thus substantially promoting the formation and accumulation of HLAs, whereas it decreased the reaction rate of HLAs formation. Moreover, carbon dioxide release was found during the process of the formation of fulvic-like acids (FLAs), and the reaction was oxygen-independent. Additionally, the formation and transformation of products without MnO2 do not obey kinetics equations, whereas the darkening reaction with MnO2 followed the pseudo-second-order and pseudo-zero-order kinetics equations. These findings provide new insights into the behaviours and fate of the oxygen-mediated humification process and related reaction products.Beyond simple identification of either the presence or absence of microplastic particles in the environment, quantitative accuracy has been criticised as being neither comparable nor reproducible. This is, in part, due to difficulties in the identification of synthetic particles amidst naturally occurring organic and inorganic components. The fluorescent stain Nile red has been proposed as a tool to overcome this issue, but to date, has been used without consideration of polymer specific fluorescent variability. The aim of this study was to evaluate the efficacy of Nile red for microplastic detection by systematically investigating what drives variations in particle pixel brightness (PPB). The results showed that PPB varied between polymer type, shape, size, colour and by staining procedure. Sand, an inorganic component of the sample matrix does not fluoresce when stained with Nile red. In contrast the organic components, wood and chitin, fluoresce between 1.40 and 12 arbitrary units (a.u.) and 32 and 74 a.u. after Nile red staining, respectively. These data informed the use of a PPB threshold limit of 100 a.u., which improved the detection of EPS, HDPE, PP and PA-6 from the 6 polymers tested and reduced analysis time by 30-58% compared to unstained samples. Conversely, as with traditional illumination, PET and PVC were not accurately estimated using this approach. This study shows that picking a threshold limit is not arbitrary but rather must be informed by polymer specific fluorescent variability and matrix considerations. This is an essential step needed to facilitate comparability and reproducibility between individual studies.Electrodialysis self-reversal (EDR) technology has attracted in the treatment of water for domestic and industrial uses. The self-reversal consists of a frequent reversal of the direction of current between the EDR-cell electrodes to combat fouling of ion exchange membranes (IEMs). Irrespective of the EDR self-cleaning processes, the role of natural organic matter and their complexing ability with metal ions on IEMs fouling is partially understood. The objective of this review is to identify the research gaps present in the elucidation of IEM fouling routes. The common IEMs' foulants are identified, and several fouling mechanisms are briefly discussed. The effectiveness of self-cleaning mechanisms to reduce IEMs fouling is also be discussed. Dissolved organic carbon (DOC) possesses high chelation which forms metal complexes with di and trivalent cations found in water. The role of ternary complexes, e.g. M2+/3+-DOC and membrane surface, on membrane fouling via surface bridging, are also addressed. Finally, mitigation methods of IEMs membrane fouling are also discussed.
Here's my website: https://www.selleckchem.com/products/ml198.html