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Facial information plays an important role in human communication, e.g., rich and nuanced facial expressions effectively convey emotions. Traditional data such as 2D facial images and videos are susceptible to perturbation from lighting and occlusion, while 3D static data such as mesh models lack the temporal information which is necessary to describe facial dynamics. Therefore, researches on 4D facial data (3D facial models together with time as the fourth dimension) have received considerable attention in recent years. 4D data can simultaneously reflect the complex facial temporal and space information. To fully explore these characteristics, we present a systematic overview of the 4D facial research in this paper. We give a review in terms of historical development of 4D facial datasets, acquisition process of these datasets, related algorithms and applications, and discussion of outstanding issues. We also analyze the 4D facial research works by summarizing and comparing them; in particular, we present the results on three kinds of tasks conducted on the 4D facial datasets, i.e., expression-related tasks (AU detection, expression recognition and retrieval), generation tasks (3D facial reconstruction, facial expression and facial animation generation), and other tasks (facial registration, facial recognition and facial disease diagnosis). Finally, we summarize the future research directions. [Display omitted] • We provide a comprehensive overview of a 4D facial dataset. • We classified and elaborated on the different facial studies conducted using 4D facial datasets. • We summarize the future research direction. [ABSTRACT FROM AUTHOR]

• Four kinds of ice-making refrigeration cycles were studied with 1-D models. • 2-stage compression and ejector systems were analyzed with exergy methods. • 2-stage compression and medium-pressure ejector system is optimal in heat recovery. • 2-stage compression and low-pressure ejector system is better for ice making only. • The optimized order of components is obtained by using the exergy analysis. The transcritical CO 2 direct cooling technology was used for the first time in the indoor venues of the 2022 Beijing Winter Olympic Games. The technology has a series of advantages, such as compact structure, uniform ice temperature, energy saving and environmental protection. In order to further reduce the power consumption and improve the performance, two-stage compression and low-pressure ejector direct cooling ice making system (TCLES) and two-stage compression and intermediate-pressure ejector direct cooling ice making system (TCIES) are studied. The performance of the systems is simulated by constructing a one-dimensional thermodynamic model. The impacts of the gas cooler pressure, gas cooler outlet temperature, evaporation temperature and intermediate pressure on these systems are considered. It is showed that TCLES and TCIES have their own advantages when the system is without and with heat recovery, and found that two-stage compression improves the system performance more than the ejector when only the cooling performance is considered. On this basis, conventional exergy and advanced exergy analysis of both systems are carried out. Advanced exergy analysis shows that exergy destruction can be avoided mainly in low-pressure and high-pressure compressors of both systems. Besides, the influence of gas cooler pressure on exergy destruction characteristics is discussed. When controlling the gas cooler pressure at 9.0 MPa, the avoidable endogenous exergy destruction of compressors and ejector is reduced by a maximum of 4.14% and 13.92% for TCLES and reduced by a maximum of 16.15% and 28.04% for TCIES. [ABSTRACT FROM AUTHOR]

Abstract Blue holes can provide valuable information regarding paleoclimate, climate change, karst processes, marine ecology, and carbonate geochemistry. The Sansha Yongle Blue Hole, located on Yongle Atoll in the Paracel Islands in the South China Sea, is the deepest blue hole in the world. A comprehensive investigation of the blue hole was conducted to determine the hydrochemical properties and associated redox processes active in the water column. Results indicate the presence of two thermoclines, one at 13–20 m and a second at 70–150 m, dividing the water column into five stratified water layers. Based on redox state, the water column can be divided into three layers: an oxic layer in the top 70 m, a chemocline at 70–100 m, which acts as a redox boundary, and an anoxic deep layer. In the oxic layer, photosynthesis in the oxic layer above the seasonal thermocline, results in nutrient uptake, transformation of inorganic carbon to organic carbon in the top mixed layer above the seasonal thermocline; Below the seasonal thermocline, organic matter degradation and nitrification, which are the main biological process at depths around 30 m and 50–70 m, lead to the accumulation of nitrate and a decrease in dissolved oxygen and pH; whereas photosynthesis is dominant at depths of 30–50 m, leading to increase in dissolved oxygen and pH. Within the chemocline, organic matter decays via a variety of reactions (e.g. aerobic mineralization, denitrification and anammox), leading to sharp decreases in the oxidizing chemical species (e.g., dissolved oxygen and nitrate) and corresponding increases in the reduced species (e.g., ammonium and sulfide). Within this layer, about 60% of the nitrogen is lost and chemoautotrophic/photoautotrophic production may contribute significantly to particulate organic carbon. Within the deep anoxic layer, sulfate reduction and degradation of organic matter result in accumulations of sulfide, dissolved inorganic carbon, and nutrients. Graphical abstract Unlabelled Image Highlights • Distinct water layers involve different redox/nitrification-denitrification process. • A 30-m thick chemocline separates the upper oxic layer and the deep anoxic layer. • The blue hole is a net source of N 2 O and CH 4 to the atmosphere. [ABSTRACT FROM AUTHOR]

Graphical abstract Breakthrough curves of acetaldehyde and acetone in binary system. Highlights • Adsorption isotherms of acetaldehyde/acetone onto coconut shell activated carbon were obtained in single and binary systems. • Henry's law constant and the selectivity were investigated to understand adsorbent and adsorbate affinity. • Integral free energy functions were useful parameters to understand adsorption behavior. • Adsorbed acetaldehyde was displaced by acetone in co-adsorption system. Abstract The adsorption characteristics of acetaldehyde/acetone onto coconut shell activated carbon (CSAC) were investigated with a dynamic apparatus. The Langmuir, Freundlich and Sips models were used to analyze the adsorption isotherm data in single gas system, revealing that the Freundlich model most suitably described the adsorption of the two gases. Henry's law constant and the selectivity were investigated based on adsorption isotherms to understand adsorbent and adsorbate affinity. A thermodynamic study also revealed that the adsorptions were exothermic and phyiscal. The adsorption of these studied gases is likely to be heterogeneous. Acetone formed the more ordered configuration on CSAC, but molecular acetaldehyde has higher degree of freedom. For the binary adsorption system, the equilibrium data fit well with the Extended Freundlich model. The competitive adsorption experiment indicated that acetone was more selectively adsorbed than acetaldehyde on CSAC. In particular, because of the displacement of adsorbed acetaldehyde by acetone the acetaldehyde demonstrated a maximum excess concentration. [ABSTRACT FROM AUTHOR]

SBA-15 mesoporous materials loaded with 8%–42% TiO 2 were prepared by post-synthesis hydrolysis using ilmenite as the TiO 2 source. X-ray diffraction, high-resolution transmission electron microscopy, nitrogen adsorption–desorption measurements, and Fourier-transform infrared, X-ray photoelectron, Raman, and ultraviolet-visible spectroscopies were used to investigate the TiO 2 /SBA-15 morphology and crystal structure. The results show that TiO 2 was successfully loaded on the mesoporous SBA-15 and the highly ordered two-dimensional hexagonal structure was stable. The photocatalytic performances of the samples in dimethoate degradation under simulated solar light were investigated. The photocatalytic activity initially increased and then decreased with increasing TiO 2 loading. The 26% TiO 2 /SBA-15 sample showed the highest photocatalytic activity and completely degraded dimethoate within 7 h. The catalytic activity of TiO 2 /SBA-15 was 62% higher than that of pure TiO 2 . This may be because of a synergistic effect resulting from the adsorption of dimethoate on the mesoporous material. The presence of Ti–O–Si species enhances the TiO 2 surface acidity and formation of surface adsorption sites; The adsorption and electron delocalization properties of SBA-15 are the main reasons for the observed enhancement of the pesticide degradation rate. These improves the TiO 2 /SBA-15 photocatalytic activity. TiO 2 /SBA-15 maintained high photocatalytic activity and good stability during four cycles, with a dimethoate degradation rate greater than 94%. The byproducts generated during photocatalysis were identified using gas chromatography-mass spectrometry. The photocatalytic degradation of dimethoate followed first-order kinetics. The mechanism of the photocatalytic degradation of dimethoate was investigated. [ABSTRACT FROM AUTHOR]

Fe and/or Mn/SBA-15 catalysts were prepared by the impregnation method using low-cost fly ash-derived SBA-15 molecular sieve as support and tested towards NH 3 -SCR. Powder XRD, N 2 adsorption, XPS, H 2 -TPR and SEM techniques were used for catalyst characterization and investigation of relationships with the catalytic activity. The Fe-Mn/SBA-15 catalyst exhibited significantly higher NH 3 -SCR activities than Mn/SBA-15 or Fe/SBA-15 in the 150–250 °C range owing to some developed synergistic effects between Mn and Fe. In particular, the addition of Mn improved the dispersion of Fe 2 O 3 on the catalyst surface, while the addition of Fe promoted the formation of single β-MnO 2 phase. The high dispersion of Fe 2 O 3 , the appropriate Mn 4+ /Mn 3+ ratio, the concentration of adsorbed oxygen and the low-T enhanced redox activity of the Fe-Mn/SBA-15 improved its NH 3 -SCR activity. This work opens new avenues of recycling fly ash formed in coal-fired power plants (reducing environmental pollution) and developing low-cost SCR catalysts for NO x pollution control. [ABSTRACT FROM AUTHOR]

Chromium oxide is widely used in national defense, hard alloy, alloy, pigment, vacuum plating, consumables and high purity alloy and belong to one of the main products of chromate production industry. In the present study, a novel cleaner process is proposed to synthesize nanostructure chromium oxide (Cr 2 O 3 ) from waste source containing chromium (VI). Hydrated chromic oxide was prepared by combination membrane and hydrothermal method. After calcined, chromium (III) compound: nanostructure chromium oxide (SNCO) was obtained. In the membrane electrolyte stage, this way can reduce the amount of acid added to adjust the solution pH. Besides, addition of CO 2 into the cathode compartment could improve the current efficiency and desalination efficiency, while decrease the energy consumption. Then the products were characterized. Combined with the experiment results of TGA and XRD, the potential formation mechanism of hydrated chromic oxide was proposed. The fine structure of the product was analyzed by SEM and TEM. It was proved that the nanostructure chromium oxide with good crystallinity was obtained. The UV–Vis was used for optical properties, which proved that it had good optical properties. [ABSTRACT FROM AUTHOR]

Using an alkali two-step hydrothermal method, SBA-15 mesoporous molecular sieves were prepared from fly ash used in a thermal power plant in Inner Mongolia (China). The effect of alkali solution (i.e., NaOH), added in different amounts at 95 °C, on the desilication rate of the ash was determined. During the 48-h hydrothermal crystallization process at 110 °C, sieves were obtained using Na 2 SiO 3 solution as the silicon source, hydrochloric acid to adjust the pH value, and P123 (PEO-PPO-PEO) as a template. Amino-functionalized molecular sieves were prepared at 120 °C, using 3-aminopropyltriethoxysilane as a modifier and toluene as the solvent. The prepared SBA-15 and NH 2 -SBA-15 molecular sieves were characterized via X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and N 2 adsorption. The effects of adsorption time, temperature, pH value, and the initial concentration of lead ions (Pb 2+ ) on the efficiency of Pb 2+ removal were investigated using NH 2 -SBA-15 as an adsorbent. The results revealed that, like its SBA-15 counterpart, NH 2 -SBA-15 has a typical two-dimensional hexagonal pore structure, with lower specific surface area, average pore diameter, and pore volume compared with its SBA-15 counterpart. Furthermore, the Pb 2+ -removal efficiency increased gradually with increasing adsorption time, adsorption temperature, and initial concentration of Pb 2+ . However, when the pH value was increased, the efficiency increased initially and decreased thereafter. The maximum removal rate (>98%) after 60 min at 30 °C was obtained at a pH value of 5 and a Pb 2+ concentration of 100 mg/L. The adsorption process of Pb 2+ and the corresponding adsorption isotherm were well described by the second-order kinetics model and the Langmuir isotherm model, respectively, and an equilibrium adsorption amount of 131 mg/g was realized. The fly-ash-based SBA-15 mesoporous molecular sieve adsorbent, developed and subsequently modified in the present study, exhibited improved selectivity and adsorption capacity, and was less expensive than existing adsorbents. This sieve can provide effective technical support for control of the industrial heavy-metal-contaminated wastewater, and provides a new approach for the efficient utilization of fly ash. [ABSTRACT FROM AUTHOR]

The promotional effects of Cu and Fe over the V 2 O 5 -WO 3 /TiO 2 NH 3 -SCR catalyst for the oxidation of Hg 0 and the selective catalytic reduction of NO by NH 3 were investigated in the temperature range of 280–360 °C. Cu or Fe addition, especially Cu, improved the catalytic performance of V 2 O 5 -WO 3 /TiO 2 . The results show that Cu 2 + was the main Cu species in the Cu-containing catalyst, whereas FeVO 4 was formed in the Fe-containing catalyst. Well-dispersed active species, good redox properties and abundant chemisorbed surface oxygen species on the catalyst surface were responsible for the high catalytic performances. Hg 0 oxidation over the V-based catalysts may follow a Mars-Maessen mechanism. [ABSTRACT FROM AUTHOR]

First principles calculations were carried out for α-Al 2 O 3 (0001) surface and γ-TiAl(111)/α-Al 2 O 3 (0001) interface to study the adhesion properties of the interface and to clarify the mechanisms that govern the adhesion of TiAl and its oxidation product Al 2 O 3 . Two type interface models, the TiAl(111) with Al- and O-terminated α-Al 2 O 3 (0001) surfaces denoted as T(A 1 )-type and T(O T )-type interface, respectively, were considered. The Universal Binding Energy Relation (UBER) was used to determine the separation between TiAl and Al 2 O 3 and the work of adhesion of the γ-TiAl(111)/α-Al 2 O 3 (0001) interface. Optimization was then performed for all interfaces considered here using the separation obtained with UBER. The lowest work of adhesion is −1.05 J/m 2 for the T(A 1 )-type interface and is −4.04 J/m 2 for the T(O T )-type interface. There exists competition between O–Ti and O–Al (on the TiAl side) interactions; however O–Al bond is stronger than O–Ti bond because the main body of the Al valences is involved in the hybriding with O p electrons, while only part of the Ti d valence is involved in the O–Ti bonding. Thus the O–Al interaction dominates the adhesion between TiAl(111) and Al 2 O 3 (0001) surfaces, and it can be inferred that an Al-rich TiAl surface will favor the adhesion between TiAl/Al 2 O 3 . [ABSTRACT FROM AUTHOR]

Reinforced thermoplastic pipes (RTP) are widely used in the offshore oil and gas production industry for their excellent flexibility, corrosion resistance and internal pressure resistance. RTPs inevitably experience extreme environmental loads including internal pressure and tensile load in the procedures of installation and operation, which influence the structural integrity and safety. Therefore, reinforced layers of RTP are designed to bear internal pressure and tensile load. Herein, the mechanical behavior of fiber-reinforced thermoplastic pipe that consisting of aramid fiber braid reinforced layers is investigated by combination of numerical simulation and experimental methods. The full-scale internal pressure bursting experiments of 1-inch aramid fiber RTPs were carried out to study the burst pressure and failure behavior. A finite element model of aramid fiber RTP is established using ABAQUS, which considers the material nonlinearities as well as frictional interactions between layers. Based on the finite element model which validated by the experimental results, the mechanical behavior of fiber reinforced thermoplastic pipe subjected to internal pressure and tensile load is investigated in detail. The current study compares the influence of braided angle of fiber-reinforced layers, friction coefficient between each layer and load conditions on the mechanical behavior of RTPs. The experiment results reveal that the bursting pressure of 1-inch aramid fiber RTPs is about 76.1 MPa. The failure of aramid fiber RTP under internal pressure is dictated by leakage due to the fracture of fiber-reinforced layers and the fracture of the internal layer at the end fitting. It is worth noting that the braiding angle renders an obvious influence on mechanical properties of fiber-reinforced RTPs, whereas the mechanical behavior remains insensitive to friction coefficient between layers. Moreover, the synergistic influence of internal pressure and tensile load significantly affects the mechanical behavior of fiber-reinforced RTPs. The current study shall serve as a reference for the design and application of fiber-reinforced thermoplastic pipes in marine oil and gas production. • The full-scale internal pressure bursting experiments of 1-inch aramid fiber RTP were carried out to investigate the failure behavior of the RTP, and the failure model and ultimate load of aramid fiber reinforced thermoplastic flexible pipe under internal pressure were clarified. • A finite element model of aramid fiber RTP is established, which considers geometrical and material nonlinearities as well as frictional interactions between layers. • The influence of braided angle of fiber-reinforced layers, load conditions and friction coefficient between each layer on the mechanical behavior of RTPs were studied in detail. [ABSTRACT FROM AUTHOR]

The Changjiang (Yangtze River) Diluted Water (CDW) plume substantially impacts the biogeochemical processes off the estuary and its adjacent area, resulting in considerable environmental and ecological effects. Based on survey data in the northeastern area off the Changjiang Estuary (CE) obtained in the summers of 2008 and 2013, the hypoxia induced by the offshore detached CDW plume and the associated controlling mechanisms were investigated. The results show that the offshore transport of the CDW plume caused a dispersed low-salinity area in the northeastern area off the CE during summer, in sharp contrast with the surrounding high-salinity and high-density waters. There was a hypoxic area with low-pH (i.e., acidification) near the 40-m isobath in bottom waters in the northeastern area off the CE, and its position generally corresponded to the surface offshore CDW plume. In the area affected by the offshore low-salinity water, the surface patch-like phytoplankton bloom and the organic debris produced in situ were the material drivers of the bottom oxygen consumption and led to the corresponding relationship between the bottom hypoxic zone and the high chlorophyll-a (Chl-a) area at the surface. We consider that the local stratification caused by the offshore low-salinity water and the stable environment within the detached CDW plume constituted the external dynamic conditions for maintaining the bottom hypoxia. Our results demonstrate that the offshore detached CDW plume in the northeastern area off the CE may contribute to the formation of a local hypoxic center with low pH. This study would provide basis for understanding of the physical-biogeochemical processes and environmental responses in the offshore areas of the CDW plume. Unlabelled Image • Co-occurrence of offshore diluted water plume and hypoxia was observed in the northeastern area off the Changjiang Estuary • The surface patchness of phytoplankton bloom corresponded to the bottom hypoxic zone • Offshore detachment of the Changjiang Diluted Water can contribute to the formation of hypoxia and acidification [ABSTRACT FROM AUTHOR]

Coppicing is a highly effective method of producing a great deal of fast growing, sustainable timber without the need for replanting. Tamarix chinensis , a native salt-tolerant species, plays an important role in the ecosystems of arid saline alkali soil and coastal wetlands in northern China. In this study, we conducted a coppicing field experiment on T. chinensis to study the vigor of resprouting over a 4-year monitoring period in the coastal wetland of Laizhou Bay, China. Results of this study show that the growth of coppiced T. chinensis was vigorous and conformed to an "S-curve" type growth pattern. The height and crown of coppiced T. chinensis recovered quickly to the initial level by the 2nd year of regrowth and its aboveground biomass regained 93.5% of the previous level by the 4th year. The carbon stock in the T. chinensis wetland was significantly increased by the coppicing operation. Carbon stocks in the aboveground parts and soil (0–100 cm) increased by 222.6 g m−2 and 588.9 g m−2, respectively, during the 4-year experimental period. These values are 43% and 74% higher, respectively, than those in the control plot over the same period. These results indicate that coppicing provides a practical means for promoting regeneration and rejuvenation of Tamarix spp. forests as well as a new approach to increasing biomass and carbon stocks in the coastal wetlands of northern China. [ABSTRACT FROM AUTHOR]

The electrochemical NRR, which can be driven by renewable energy sources, is an emerging strategy for addressing the high energy consumption and CO 2 emission issues caused by the traditional Haber–Bosch ammonia synthesis technique. FePc catalyzes the electrochemical ammonia synthesis reaction well, but intermolecular π-stacking and multi-layer overlapping lead to low NH 3 yields. Here, [Bmim][Cl] and [Bmim][NTF 2 ] ILs were used to induce monolayer dispersion of FePc. Ionic-liquid-induced FePc electrocatalyst, namely FePc/C-700, which was constructed with ILs as the carbon source, gave an excellent NH 3 yield (24.25 μg mg cat −1 h−1) and Faradaic efficiency (30.59%) at − 0.1 V. The formation of a monolayer FePc structure was confirmed by HAADF-STEM and XANES. The results of DFT calculations and NRR experiments showed that the monolayer FePc structure promoted N 2 adsorption and inhibited the competitive HER. These results will be useful in the design of active sites of layered macromolecules to achieve efficient electrochemical NRR. [Display omitted] • The monolayer FePc/C-700 catalysts successfully synthesized in this work exhibits excellent catalytic activity in the NRR. • Using ILs to induce monolayer dispersion of FePc and as carbon sources to suppress the formation of multi-layer FePc structure • This work proves that the formation of the multi-layer FePc structure affects the activation of N 2. [ABSTRACT FROM AUTHOR]

A series of vanadium based catalysts (V x Mn(4− x)Mo3Ce3/Ti) with different vanadium (x wt.%) and manganese ((4− x) wt.%) contents have been prepared by the wet impregnation method and investigated for selective catalytic reduction (SCR) of NO x by NH 3 in the presence of 8 vol.% H 2 O and 500 ppmV SO 2. The physicochemical characteristics of the catalysts were thoroughly characterized. The SCR of NO x by NH 3 (NH 3 -SCR) activity, especially the low-temperature activity, significantly increased with increasing V 2 O 5 content in the catalyst until the V 2 O 5 content reached 1.5 wt.%, which corresponds well with the redox properties of the catalyst. All of the metal oxides were well dispersed and strongly interacted with each other on the catalyst surface. V mainly exists in the V5+ state in the catalysts. The strong synergistic effect between the vanadium and cerium species led to formation of more Ce3+ species, and that between the vanadium and manganese species contributed to formation of more manganese species with low valences. All of the catalysts exhibited strong acidity, while the redox properties determined the NH 3 -SCR activity, especially the low-temperature activity. H 2 O and SO 2 had severe inhibiting effects on the activity of V1.5Mn2.5Mo3Ce3/Ti. However, good H 2 O and SO 2 resistance and high NO x conversion by V1.5Mn2.5Mo3Ce3/Ti could be achieved in the presence of SO 2 and almost no decline was observed in a long-term test at 275°C for 168 hr in the presence of SO 2 and H 2 O, which can be attributed to the sulfate species formed on the catalyst surface. Unlabelled Image [ABSTRACT FROM AUTHOR]

• The impacts of the COVID-19 pandemic on the occurrence of OPEs were investigated. • Total OPE concentrations decreased by 67–70% in waters after the COVID-19 outbreak. • OPEs released from masks were insufficient to increase their concentrations in water. • Spatial distribution of OPEs was affected by riverine inputs & coastal engineering. • TCEP, TNBP, and BDP showed potential ecological risks to aquatic organisms. Organophosphate esters (OPEs) are a group of synthetic chemicals used in numerous consumer products such as plastics and furniture. The Coronavirus Disease 2019 (COVID-19) pandemic significantly slowed anthropogenic activities and reduced the emissions of pollutants. Meanwhile, the mismanagement of large quantities of disposable plastic facemasks intensified the problems of plastic pollution and leachable pollutants in coastal waters. In this study, the joint effects of the COVID-19 outbreak on the occurrence of 12 targeted OPEs in the waters of Laizhou Bay (LZB) were investigated. The results showed that the median total OPE concentrations were 725, 363, and 109 ng L−1 in the sewage treatment plant effluent, river water, and bay water in 2021, decreased significantly (p < 0.05) by 67%, 68%, and 70%, respectively, compared with those before the COVID-19 outbreak. The release potential of targeted OPEs from disposable surgical masks in the LZB area was ∼0.24 kg yr−1, which was insufficient to increase the OPE concentration in the LZB waters. The concentrations of most individual OPEs significantly decreased in LZB waters from 2019 to 2021, except for TBOEP and TNBP. Spatially, a lower concentration of OPEs was found in the Yellow River estuary area in 2021 compared with that before the COVID-19 pandemic due to the high content of suspended particulate matter in the YR. A higher total OPE concentration was observed along the northeastern coast of LZB, mainly owing to the construction of an artificial island since 2020. The ecological risks of the OPE mixture in LZB waters were lower than those before the COVID-19 outbreak. However, TCEP, TNBP, and BDP should receive continuous attention because of their potential ecological risks to aquatic organisms. [Display omitted] [ABSTRACT FROM AUTHOR]

• PPCPs decreased gradually in detection rates and levels from rivers to coastal seas. • Amoxicillin and p-hydroxybenzoic acid accounted for over 50% of the total PPCPs. • Southeastern waters outside the yangtze estuary had higher PPCP concentrations. • PPCP mixtures posed medium to high risks to different aquatic organisms. • Priority PPCPs with high ecological risks were identified. Pharmaceuticals and personal care products (PPCPs) have captured global concern due to their detrimental effects on aquatic organisms. Thirty PPCPs were analyzed in the water of the Jiaozhou Bay watershed, the Yellow Sea (YS) and the East China Sea (ECS) in China to investigate the distribution and risk of PPCPs from rivers to coastal seas, which are not yet well documented. The results showed the prevalence of the target PPCPs with a downward trend in detection frequencies and total concentrations from rivers (675 ng/L on average) to bay (166 ng/L) and to coastal seas (103 ng/L). Antibiotics and personal care products (PCPs) were dominated by amoxicillin (AMOX) and p-hydroxybenzoic acid, respectively, while the dominant estrogens were inconsistent in different regions. Spatially, the total PPCP concentrations were higher in the ECS than that in the YS due to the larger quantity of sewage flowing into the ECS. Additionally, higher total PPCP concentrations were appeared in the southeastern waters outside the Yangtze estuary and Hangzhou Bay of the ECS. The PPCP mixtures might pose medium to high risk to aquatic organisms in general. The total risk quotient (RQ T) of antibiotics and PCPs to algae was higher than that to crustacean and fish, while estrogens may cause the greatest damage to fish. Despite the higher PPCP concentrations in river water than in seawater, the RQ T of PPCPs in bay water was generally higher than that in river water, which may be associated with the susceptibility of marine organisms. Furthermore, the high-risk pollutants that need special concern in different regions were clarified, showing that AMOX, 17ß-estradiol, and estriol deserve the highest-priority in rivers, bay, and coastal waters, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

Nutrients play a major role in sustaining marine ecosystems. However, in the past few decades, nutrient inputs from land have significantly changed worldwide, resulting in the variations in nutrient concentrations and compositions in marginal seas. Based on historical data, the long-term variation patterns of nutrients and its compositions, as well as its potential influencing factors, were presented in the southern Yellow Sea. The concentrations of NO 3 -N and dissolved inorganic nitrogen (DIN) in the southern Yellow Sea have been continuously increasing from the 1980s, with a most rapid increase after the mid-1990s. While the concentrations of SiO 3 -Si and PO 4 -P generally exhibited a decreasing trend before the mid-1990s, and then gradually increased. The N/P ratio has been continuously increasing from the 1980s and run up to a level of >16 at the end of the last century. The Si/N ratio decreased rapidly from the mid-1980s to the mid-1990s and then maintained a low level of ~1 at the end of the last century and at the beginning of this century. Similar to the variation of SiO 3 -Si, the Si/P ratio decreased from the 1970s to the mid-1990s and then started to increase gradually. There was an evolution trend from N limitation to P and Si limitation in the southern Yellow Sea. The variations in the concentrations of nutrients were related to the variations of the riverine flux and atmospheric deposition, and especially the long-term variations of PO 4 -P and SiO 3 -Si concentrations were both consistent with the variation of precipitation. In addition, the nutrient transport from the Kuroshio Subsurface Water to the continental shelf, in combination with the cultural eutrophication in the coastal zones, may also influence the nutrient levels in the southern Yellow Sea under the global change. [ABSTRACT FROM AUTHOR]

• Yellow River PAH input & sea currents determined PAH spatial distribution in the sea. • Yellow River alluvial loess solid dilution effect led to lower PAH levels in the sediment. • Yellow River & Yellow Sea water dilution effect led to lower PAH levels in the water. • PAH properties decided its partitions in surface/bottom water & bottom water/sediment. • PAH ecological risks in both water and sediment were negligible or acceptable. The marginal Bohai Sea, connected to the northwestern Pacific Ocean, is threatened by human activity. The Yellow River, the second largest river in China, drains large amounts of water, silts, and polycyclic aromatic hydrocarbons (PAHs) into the southern Bohai Sea; however, to what extent the Yellow River inputs influence the spatial distributions and partitions of PAHs in the southern Bohai Sea is not well known. Therefore, this study collected surface water, bottom water, and sediment samples from the southern Bohai Sea and analyzed them to examine the spatial distributions and partitions of 15 priority PAHs. The results showed that PAH concentrations ranged from 26.9 to 50.1 ng L–1 in surface water, 18.8 to 44.1 ng L–1 in bottom water, and 7.4 to 143.9 ng g–1 in sediment, with higher proportions of four-, five-, and six-ring PAHs in sediment than in water. PAH inputs from the Yellow River and sea coastal currents determined the spatial distribution of PAH concentrations in water and sediment, with an overall decrease from the estuary to the southeast. However, the solid dilution effect of input silts from the Yellow River and the liquid dilution effect of water from the Yellow River and Yellow Sea led to lower PAH concentrations in the water and sediment of the southern Bohai Sea than those in other areas of the Bohai Sea. PAH exchange between the atmosphere and seawater led to significantly higher individual PAH concentrations (except for acenaphthylene) in the surface water than in the bottom water, with ratios significantly related to the PAH n-octanol-water partition coefficient, organic carbon-water partition coefficient, and Henry's law constants. These parameters also determined PAH partitioning between the bottom water and sediment. Individual and total PAH concentrations in the sediment were significantly correlated with organic matter, clay, and silt contents. Therefore, the partitions and spatial distributions of PAHs in the southern Bohai Sea comprehensively depend on PAH properties, PAH inputs from the Yellow River and the atmosphere, sea currents, and seawater and sediment properties. The ecological risks posed by individual PAHs in both water and sediment were negligible or acceptable. [Display omitted] [ABSTRACT FROM AUTHOR]

Coastal contamination by polycyclic aromatic hydrocarbons (PAHs) is a worldwide issue. Nevertheless, the spatiotemporal distribution of PAHs in the urbanized semi-enclosed bays in China remains relatively uncharacterized. Here we present measurements of 15 priority PAHs in the water and sediment of the Jiaozhou Bay, as well the assessment of their spatiotemporal distribution, sources and ecological risk. The total PAH (ΣPAH) concentrations ranged from 23.6 to 86.2 ng L −1 in the water and from 37.7 to 290.9 ng g−1 in the sediment. The average ΣPAH concentration in the water was significantly higher in the winter (52.8 ng L −1) than in the spring (30.4 ng L −1) (α = 0.05 level). Average concentration of phenanthrene in the water was 8.9 ng L−1 in the spring and 15.7 ng L−1 in the winter and the highest of PAHs, contributing about 29.4% to ΣPAHs. Compared with three-ring PAHs, four- and five-ring PAHs were more tended to accumulate in the sediment, and the partitioning into sediment was influenced by the water salinity. The spatial distribution of ΣPAH concentrations in the water were controlled by water exchange capability. Organic matter content and sediment texture played important roles in determining the spatial distribution of ΣPAHs in the sediment. Molecular diagnostic ratio analysis indicated that pyrogenic source was the main source for PAHs in the Bay. Specifically, the positive matrix factorization (PMF) model indicated that vehicle emission, biomass combustion, coal combustion, and petrogenic sources contributed for 41.6, 20.2, 20, and 18.2% of ΣPAHs, respectively. The risk assessment by sediment quality guidelines suggested that adverse biological effects are expected to occur rarely in the sediment. Unlabelled Image • ΣPAH concentration in water was significantly higher in winter than in spring. • Water salinity may play a role in PAH partitioning into sediment. • Water exchange capability controlled spatial PAH distribution in water. • Organic matter and texture may influence spatial PAH distribution in sediment. [ABSTRACT FROM AUTHOR]

The Jiaozhou Bay is a semi-enclosed bay located in the middle of the Yellow Sea. Effluents from wastewater treatment plants have been carried into the bay, which has significantly increased the deposition of mercury. The spatial distributions of total mercury (THg) and methylmercury (MeHg) in dissolved state, in suspended matters of seawater and surface sediments at 26 locations inside the Jiaozhou Bay and five surrounding rivers in April 2018 were examined. The contents of THg and MeHg found along the eastern coast were higher than those found along the western coast, which indicated the impact of human activities (river input) on the Jiaozhou Bay. The partition coefficient (LogKd) was used to express the distribution relationships of THg and MeHg in suspended matters and dissolved state, and it was concluded that suspended matter was the main reservoir of mercury in Jiaozhou Bay seawater. The correlations between contents and physicochemical properties of seawater showed that THg and MeHg concentrations in seawater decreased with increasing salinity and pH. The effects of the mean grain diameter (MGD) and sediment organic matter (SOM) on the THg and MeHg in surface sediments were also discussed. Principal component analysis (PCA) was used to obtain the factors determining the methylation proportion in the surface sediments, indicating that the combination of human activities and natural processes affected the degree of methylation in the sediments. The spatial distribution of THg, MeHg and MeHg% was suggested to be disturbed by the interaction of natural processes and human activities (river input) by the correlation analysis of the corresponding pollutant concentrations among seawater and. Although the concentrations of THg and MeHg in seawater and sediments of the Jiaozhou Bay did not exceed the Chinese regulatory standards, the pollution levels of THg and MeHg were comparable to those in other bays in the world. Unlabelled Image • Suspended matter was the main reservoir of mercury in seawater. • The distribution patterns of THg and MeHg indicated the impact of human activities. • Key factors affecting the level of Hg by correlation were salinity, pH, SOM and MGD. • Pollution by THg and MeHg was not serious in the Jiaozhou Bay. [ABSTRACT FROM AUTHOR]

In the previous decade, neonicotinoids (NEOs) and fipronil (FIP) have received increasing attention as environmental pollutants because the high toxicity of these insecticides to nontarget arthropods has been recognized. In this study, a new method was developed for the simultaneous determination of seven NEOs and FIP and its metabolites (FIPs) in seawater and river water samples using disk-based solid-phase extraction (SPE) and high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The optimization of disk-based SPE extraction and HPLC separation parameters of target analytes was investigated. Under optimal conditions, the low limit of quantitation (LOQ) of 11 target analytes in actual water samples ranged from 0.05 ng/L to 0.50 ng/L. Satisfactory absolute recoveries (58.9%–109.9%), precision (relative standard deviations, ≤13.3%), and linearity (R 2 ≥ 0.995) were also achieved, thereby indicating that the developed method would be suitable to determine the target NEOs and FIPs in seawater and river water. Finally, the proposed method was applied to determine the amounts of these insecticides in authentic environmental water samples collected from Jiaozhou Bay, China, and its adjacent rivers. Nitenpyram, thiamethoxam, imidacloprid, clothianidin, and acetamiprid were detected, as well as FIPs in seawater and river water samples. This study is the first to report that NEOs and FIPs are detected in the coastal seawater. The total concentration of these insecticides ranged from ≤LOD to 11.19 ng/L, which indicates that these pesticides are eventually discharged into the marine environment. Therefore, it is necessary to investigate the temporal spatial distribution, migration and transformation, environmental fate, and bioavailability of these pesticides in further studies. Image 1 • SPE disk had favorablerecoveries for simultaneous enrichment of trace NEOs and FIPs. • A reliable analytical method was developed for NEOs and FIPs in water samples. • Several NEOs, FIP, and its metabolites were detected in Jiaozhou Bay coastal water. • The analysis of NEOs and FIPs in seawater was reported for the first time. • More attention has to be focused on environmental risks of the coastal area posed by NEOs and FIPs. [ABSTRACT FROM AUTHOR]

• Nb 2 O 5 addition improves the sulfur resistance of CeWTi catalyst in presence of H 2 O. • Ammonium hydrogen sulfate is preferentially formed on NbCeWTi catalyst. • More Ce x+ active sites are preserved from attack of SO x with niobia modification. • NO adsorption and nitrate formation are ensured on NbCeWTi in the presence of SO 2. CeO 2 /WO 3 -TiO 2 (CeWTi) and Nb 2 O 5 -CeO 2 /WO 3 -TiO 2 (NbCeWTi) catalysts were prepared by a sol-gel precipitation method. Both the catalysts exhibit high selective catalytic reduction of NO x with NH 3 (NH 3 -SCR) activities at 270–500 °C. The sulfur tolerances of the catalysts were evaluated at 270 °C by adding H 2 O and SO 2 in the feeding gas and NbCeWTi exhibited a significantly improved resistance. The thermogravimetric (TG) and mass spectrographic (MS) results indicated that much less sulfates formed on NbCeWTi and existed mainly in the form of ammonium hydrogen sulfate species which protected Ce x+ active sites effectively from attacking of SO 2. According to the results of temperature-programmed desorption of ammonia (NH 3 -TPD), H 2 temperature-programmed reduction (H 2 -TPR) and SO 2 oxidation, loading niobia on CeWTi inhibited the SO 2 oxidative adsorption and SO 3 production which basically reduced sulfur poisoning of the catalyst. Additionally, the niobia modification ensured the formation of nitrates from the competitive adsorption of SO 2 and hereby facilitated the nitrate SCR route based on the in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS). [ABSTRACT FROM AUTHOR]

Protein-like substances produced by biochemical reactions after disinfection of Zooplankton like Cyclops and humic substances in natural water are the main components of NOM (Natural organic matter). To eliminate early warning interference in the fluorescence detection of organic matter in natural water, a clustered flower-like AlOOH (aluminum oxide hydroxide) sorbent was prepared. HA (humic acid) and amino acids were selected as mimics of humic substances and protein-like substances in natural water. The results demonstrate that the adsorbent can selectively adsorb HA from the simulated mixed solution and restore the fluorescence properties of tryptophan and tyrosine. Based on these results, a stepwise fluorescence detection strategy was developed and used in natural water rich in zooplanktonic Cyclops. The results show that the established stepwise fluorescence strategy can well overcome the interference caused by fluorescence quenching. The sorbent was also used for water quality control to enhance coagulation treatment. Finally, trial runs of the water plant demonstrated its effectiveness and suggested a potential control method for early warning and monitoring of water quality. [Display omitted] • Adsorption pre-treatment proposed to improve fluorescence monitoring accuracy. • Selective adsorption of adsorbents with flower-like cluster structures. • Investigation of the mechanism of protein quenching in natural water. • Adsorption coagulation has promising applications in practical water treatment. [ABSTRACT FROM AUTHOR]

The effect of microwave on reactive crystallization is investigated with magnesium carbonate as the working substance. In the experiments, magnesium carbonate is precipitated by mixing aqueous magnesium sulfate and sodium carbonate solutions in a MSMPR crystallizer located in a microwave reactor. A population balance model along with crystallization kinetics is formulated to assess the influence of microwave energy input on nucleation, growth, agglomeration and breakage during crystallization process. A general high order moment method of classes (HMMC) framework is applied to solve the model numerically. The results show that crystallization kinetics parameters, including the nucleation rate constant ( k n ), the growth rate constant ( k g ), the exponent of growth rate ( g ) and the collision efficiency ( Ψ ag ) change significantly due to mass transfer enhancement in microwave field. Meanwhile, the exponent of nucleation ( n ) and the breakage rate constant ( k br ) remain constant or only change slightly. It is further discovered that the crystal suspension attenuates the microwave effect during crystallization process. [ABSTRACT FROM AUTHOR]

The effects of microwave on the induction time of CaSO 4 are studied experimentally and theoretically. In the experiments, calcium sulfate is precipitated by mixing aqueous CaCl 2 solution and Na 2 SO 4 solution. The induction time is measured by recording the change of turbidity in solution. Various energy inputs are used to investigate the effect of energy input on nucleation. The results show that the induction time decreases with increasing supersaturation and increasing energy input. Employing the classical nucleation theory, the interfacial tension is estimated. In addition, the microwave effects on nucleation order ( n ) and nucleation coefficient ( k N ) are also investigated, and the corresponding values of homogeneous nucleation are compared with the values of heterogeneous nucleation in the microwave field. A cluster coagulation model, which brings together the classic nucleation models and the theories describing the behavior of colloidal suspension, was applied to estimate the induction time under various energy inputs. It is found that when nucleation is prominently homogeneous, the microwave energy input does not change the number of monomers in dominating clusters. And when nucleation is prominently heterogeneous, although the dominating cluster size increases with supersaturation increasing, at the same supersaturation level, the dominating cluster size remains constant in the microwave field. [ABSTRACT FROM AUTHOR]

“Cr-keeper” nanoparticles (CKN) are in-situ synthesized based on the challenge of separation trace vanadium (V) from chromium (VI) in aqueous solution. Kelp is used as the bio-template and it can react with chromium (VI). Transmission electron microscopy (TEM) results reveal that CKN can copy the cell structure from kelp and the specific surface area of CKN is 343.20 m 2 /g. Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis confirm the formation of hydroxyl and Cr (III) species in CKN. The adsorption capacity of V (V) onto CKN is 51.20 mg/g and the maximum separation coefficient (β V/Cr = 3900) is achieved at pH 3.00. The adsorption kinetics follow pseudo-first-order model and Weber-Morris intra particle diffusion model. The adsorption isotherms follow the Sips model. The regeneration and reusability of CKN are discussed. All the results suggest that the utilization of biomass’s cell structure as the template for the fabrication of adsorbent with “Cr-keeper” function is excellent, which will bring new directions for Cr (VI) system purification. [ABSTRACT FROM AUTHOR]

Paralytic shellfish toxins (PSTs) producing algae are widely distributed in the global coastal aquatic environment, posing a threat to coastal ecosystem health and mariculture safety. However, the levels and potential environmental risks of PSTs frequently detected in shellfish remain largely unexplored in seawater of mariculture zones. In this study, a new method for trace detection of 13 common PSTs (<1.0 ng/L) in seawater was established based on off-line solid phase extraction (SPE) and on-line SPE-liquid chromatography-tandem mass spectrometry (on-line SPE-LC-MS/MS), and a systematic investigation of PSTs in seawater of the Laizhou Bay, a typical aquaculture bay in China, was conducted to understand their pollution status, environmental impact factors and ecological risks for the first time. Eleven PSTs were detected in the seawater of Laizhou Bay with total concentrations ranging from 0.75 to 349.47 ng/L (mean, 176.27 ng/L), which indicates the rich diversity of PSTs in the mariculture bay and demonstrates the reliability of the proposed analytical method. C1, C2, GTX2, GTX3, dc GTX2, and dc GTX3 were found to be the predominant PSTs, which refreshed the knowledge of PST contamination in the coastal aquatic environment. PST levels in seawater exhibited the highest levels in the southeastern mouth of Laizhou Bay and decreased toward the inner bay. Correlation analyses showed that climatic factors, nutrient status and hydrological conditions had significant effects on the distribution of PST in mariculture bay. Preliminary environmental risk assessments revealed that aquatic organisms throughout the waters of Laizhou Bay are at risk of chronic PST toxicity. These findings imply that the risk of PST in seawater of mariculture bay has previously been grossly underestimated, and that the coastal aquatic environment in North China and even the world may be at more serious risk of PST pollution, which should be taken seriously. [Display omitted] • A new analytical method was developed for 13 trace PSTs in seawater (<1.0 ng/L). • Various PSTs widely distributed in nearshore water was reported for the fist time. • GTXs, dc GTXs, and C-toxins are the predominant PSTs in mariculture seawater. • Aquatic organisms in the Laizhou Bay are generally at risk of chronic PST toxicity. • Nutrient and hydrological conditions affect the distribution of PST in Laizhou Bay. [ABSTRACT FROM AUTHOR]

A NbO x /Ce 0.75 Zr 0.25 O 2 (NbCZ) catalyst was synthesized by a citric acid-aided sol-gel method. It shows that above 80% NO x conversion and above 95% N 2 selectivity for the selective catalytic reduction of NO x by ammonia over this catalyst are achieved in the temperature range 200–450 °C. Based on the DRIFTS and kinetic studies over NbCZ and Ce 0.75 Zr 0.25 O 2 , the promotion mechanism by niobia loading was elucidated with an overall reaction pathway. Two different reaction routes, “L-H” mechanism via “NH 4 NO 3 + NO” at low temperatures (<200 °C) and “E-R” mechanism via “NH 2 + NO” at high temperatures (>350 °C), are presented. The niobia addition increases the surface acidity and promotes the formation of nitrates species at low temperatures. In this way, the reaction between the ads-NH 3 and nitrates species is accelerated to form NH 4 NO 3 intermediates, which then decompose to N 2 and H 2 O. The reaction of the ads-NH 3 species with gaseous NO x at high temperatures is also promoted due to the enhanced acidity and weakened thermal stability of nitrates after niobia loading. [ABSTRACT FROM AUTHOR]

Coal fly ash (CFA), is a by-product of coal combustion which has been regarded as a recalcitrant solid waste. In this work, an effective and low-cost high alumina coal fly ash catalyst was synthesised by using of high alumina coal fly ash and Fe(II)/Fe(III) oxide and the catalytic capacity of o-methyl phenol (OMP) in the Oxidative degradation was investigated. XRD, SEM and XPS were used to characterize the catalyst and the results indicated that the Fe(II)/Fe(III) oxide was successfully introduced. The character results showed that the surface area of CFA increased with increasing the loading content of the Fe(II)/Fe(III) oxide and the biggest surface area is about 69.3 m 2 /g with the loading content of 15 wt.%. The degradation experiment results showed that the catalytic ozonation capacity was affected by the loading of Fe(II)/Fe(III) oxide and the solution pH. The biggest removal efficiency of OMP and the reveal rate of COD were 100.0% and 44.5% which appeared at pH of 11 with the loading content of Fe(II)/Fe(III) oxide of 15 wt.%. The kinetic study of the catalytic ozonation degradation process revealed that the degradation process follows the first order kinetic model. It is indicats that the degradation process of OMP was derived from the heterogeneous Fenton process and affected by the solution pH. [ABSTRACT FROM AUTHOR]

The contamination status and transport of per- and polyfluoroalkyl substances (PFASs) in the seawater of the Indian Ocean (IO) and an adjacent subregion of the Northwest Pacific Ocean (NWPO) were investigated. Eight legacy PFASs were widely distributed in the surface seawater, and perfluoroheptanoic acid (PFHpA) and perfluorooctanoic acid (PFOA) were the two predominant PFASs. ΣPFAS concentration decreased in the following order: NWPO>Joining area of Asia and Indian-Pacific Oceans (JAIPO)>Northeast Indian Ocean>Southwest Indian Ocean. Hexafluoropropylene oxide-dimer acid, a replacement surfactant for PFOA was extensively detected in the IO (~34.8 pg/L) for the first time, showing an early sign of emerging PFAS spread in global open oceans. Eight depth profiles across the JAIPO (down to 5433 m depth) revealed a "surface-enrichment" and "depth-depletion" pattern for PFASs in the water column, and two noticeable fluctuations were mainly located at depths of 150–200 and 200–500 m. Physical processes, including eddy diffusion, and the origin and trajectory of water mass were crucial factors for structuring PFAS vertical profiles. Mass transport estimates revealed a remarkable PFOA contribution through the JAIPO to IO carried by the Indonesian Throughflow, and a nonnegligible PFHpA contribution from Antarctic Immediate Water to deep water of the JAIPO driven by thermohaline circulation. [Display omitted] This study clarified that legacy and emerging PFASs in the different open areas of the Indian Ocean (IO), contributing to the understanding of the contamination status, transport, and interbasin exchange of PFASs in global open oceans. HFPO-DA was extensively detected in the IO, showing an early sign of emerging PFASs spread in global open oceans. Our results demonstrated the effect of physical processes, including oceanic circulation, eddy diffusion, and origin and trajectory of water mass, on the structuring of large-scale transport and fate of PFASs and found the remarkable contribution of PFASs from the Pacific Ocean to the IO. • The total PFASs concentration decreased in an order of NWPO>JAIPO>NWIO>SWIO. • PFOA and PFHpA contamination in the Indian Ocean are more prominent than PFOS. • HFPO-DA are detected extensively for the first time in the Indian Ocean. • PFASs vertical profiles show a "surface-enrichment and depth-depletion" pattern. • A remarkable PFOA contribution from the JAIPO to the Indian Ocean is demonstrated. [ABSTRACT FROM AUTHOR]

[Display omitted] • NH 4 Mo 7 O 24 promotes polymerization of VO x with increased solution acidity. • Steric interaction occurs on V-Mo/TiO 2 depending on loading of metal oxides. • More VO x polymers generate on TiO 2 with MoO x addition at low V loading. • Crystalline V 2 O 5 and MoO 3 form due to steric hindrance with excess monolayer loading. • Feasibly reducible VO x species facilitates adsorption and activation of NH 3. Monometallic (V/TiO 2 and Mo/TiO 2) and bimetallic (V-Mo/TiO 2) catalysts were prepared for selective catalytic reduction (SCR) of NO x with NH 3 at low temperatures (100–300 °C). The effect of MoO x on the dispersion of vanadia with different V 2 O 5 loadings was investigated on the basis of X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), N 2 adsorption–desorption, Raman spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). As the molybdenum precursor, NH 4 Mo 7 O 24 increased the solution acidity and promoted polymerization of VO x in liquid phase. At a low vanadia loading, polymerization of VO x , the adsorption rate of NH 3 and transformation of active intermediate species NH 2 were enhanced by adding MoO x , while at a high vanadia loading, the steric hindrance became dominant leading to the formation of crystalline V 2 O 5 and MoO 3 and caused decline in SCR activity. [ABSTRACT FROM AUTHOR]

This paper presents a computational investigation of the hydrodynamics and the reaction behavior in a fluidized-bed CO 2 capture reactor. Integrating CO 2 adsorption kinetics with the two fluid model, a multiphase flow and reaction model is established. Computational fluid dynamics analyses are performed, and the influences of various operating conditions are evaluated. The results indicate that velocity, volume fraction and species concentration of the gas and particle phase are significantly nonuniform inside the fluidized-bed reactor. Adsorption reaction mainly takes place in the bottom bubbling fluidized bed. CO 2 capture efficiency decreases with increasing the initial CO 2 content in the flue gas. A low gas velocity of 0.13–0.16 m/s leads to a higher CO 2 capture efficiency. High reaction temperatures and large sorbent circulation rates are beneficial to CO 2 removal in the current reactor. [ABSTRACT FROM AUTHOR]

A hydrodynamic model of an interconnected fluidized bed for chemical looping combustion was established based on the Eulerian–Eulerian two-fluid model with the kinetic theory of granular flow. The effect of the drag model on the computational results was investigated and detailed hydrodynamics were predicted in the three-dimensional circulating fluidized bed (composed of a riser, bubbling bed, pot-seal and cyclone). Both qualitative and quantitative results indicated that the drag model had a significant effect on the flow behavior. The Gidaspow and the Syamlal & O'Brien drag models both produced accurate predictions in this study. The pressure balance of an interconnected fluidized bed revealed that the pressure in the bubbling bed was lower than that in the pot-seal and the riser, whilst still being higher than the pressure in the cyclone. The riser and bubbling bed were individually operated in fast and bubbling fluidization regions. The three distinct regions identified from the bottom to the top of the riser were: entrance region, bulk region and exit region. The solids volume fraction was higher in the near-wall region but lower in the center region for both the riser and bubbling bed. The coupled characteristics of the fluidized bed were predominantly identified by the strong effect of operational gas velocity in the riser on the hydrodynamics in the bubbling bed. [ABSTRACT FROM AUTHOR]

Glycerol dialkyl glycerol tetraethers (GDGTs) have received considerable attention because they are useful indicators for paleoenvironment, organic matter source, and microbial community. In this study, a new simple method was developed for the analysis of GDGTs by using direct large-volume injection (LVI)–liquid chromatography (LC)–atmospheric pressure chemical ionization–mass spectrometry (APCI–MS) to reduce the usage of sediment or seawater suspended particulate matter (SPM) samples. The parameters of accelerated solvent extraction and LVI of target GDGTs were optimized. Under optimal conditions, the LVI approach (500 μL injection) coupled with LC–APCI–MS could determine various GDGTs even with 0.02–0.10 g of sediment samples or SPM samples collected from 0.2–1.0 L of marginal sea water or 10–20 L of open ocean seawater with satisfactory method precision (relative standard deviations ≤10.2%) and linearity (R 2 ≥ 0.991). Compared with the classical method, the LVI–LC–APCI–MS required significantly reduced amount of sediment or SPM sample. Finally, the proposed method was applied to determine GDGTs in real sediment samples collected from hydrothermal vent sites at the Southwest Indian Ridges. Four groups of GDGTs, namely, isoprenoid GDGTs (isoGDGTs), branched GDGTs, H-GDGTs and OH-GDGTs, and archaeol, glycerol dialkanol diethers (GDDs) and glycerol monoalkanediol diethers (GMDs) were detected with only 0.02 g of sediment sample collected from Longqi and Tianzuo hydrothermal fields. The organic matter in the sediment sample from Tianzuo was significantly affected by hydrothermal activity. In addition, isoGDGTs in seawater SPM from the open area of Eastern Indian Ocean were investigated for the first time. Six common isoGDGTs were all detected in surface and subsurface SPM samples (filtering 10 L of seawater), which indicated that the LVI approach could noticeably reduce the workload of collecting seawater SPM on board and could be used to investigate conveniently the distribution of GDGTs in water column especially in open oceans and deep seas. [Display omitted] • A new large-volume injection method is developed to detect GDGTs by using a small amount of environmental sample. • The sensitivity of the proposed analytical procedure is significantly improved compared with common injection method. • The method can noticeably reduce the workload of collecting seawater SPM from water column. • The effect of hydrothermal activity on sediment organic matter is elucidated using GDGTs as indicators. • IsoGDGTs occurring in the water column of the Eastern Indian Ocean are clarified for the first time. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulation was used to study the adsorption of single wall carbon nanotubes (SCNT) in levofloxacin (LEV) solutions of different concentrations by Radial distribution function, mean square displacement and interaction energy. The results showed that levofloxacin molecules were adsorbed around the carbon nanotubes. The adsorption effect of large concentration solution was not as good as that of low concentration solution because of agglomeration. LEV molecules with different concentration were free diffusion within 15ns, and gradually agglomerated under the influence of adsorption. The energy change is proportional to the concentration of the molecule. The distance between benzene rings corresponding to the agglomeration effect of levofloxacin molecules was 0.4 nm, which should be the effect of parallel-slipped π−π electron-donor−acceptor (EDA) interactions. The simulation results are valuable to study the adsorption and removal of benzenes by adsorbent. [Display omitted] • The absorption of antibiotics by carbon nanotubes was simulated by molecular dynamics. • The agglomeration process of organic molecules was found in the process of molecular simulation. • By calculating the radial distribution between two levofloxacin molecules, it is concluded that the interaction is the parallel-slipped π−π electron-donor−acceptor interactions. [ABSTRACT FROM AUTHOR]

We investigated the spatiotemporal distributions, risks, and prioritization of 15 widely used antibiotics in Laizhou Bay (LZB). Water samples (145) were collected from LZB and its estuaries and analyzed. Twelve antibiotics, with total concentrations of 241–1450 and 69–289 ng L−1 in estuarine water and seawater, respectively, were detected, with the contributions of norfloxacin, ciprofloxacin, and amoxicillin exceeding 70%. Amoxicillin was firstly determined, which contributed to 20% and 46% of the total antibiotics during summer and spring, respectively. Higher antibiotic concentrations were observed in the sea located adjacent to aquaculture bases and the Yellow River Estuary, which are significantly influenced by mariculture and riverine inputs, respectively. Veterinary antibiotics showed higher total concentrations in summer compared to spring, indicating a higher degree of their usage in mariculture in summer. The antibiotic mixtures posed high risk to algae and low to medium risks to crustaceans and fish. Amoxicillin and norfloxacin were identified as high-risk pollutants. Additionally, amoxicillin and ciprofloxacin showed medium to high resistance development risks. Previous studies on antibiotics in the LZB did not determined amoxicillin and thus underestimated antibiotic contamination, ecological risk, and resistance development risk. Amoxicillin, norfloxacin, and ciprofloxacin should be prioritized in risk management. [Display omitted] • Amoxicillin in the Laizhou Bay water was firstly determined. • Norfloxacin and amoxicillin concentrations were higher than other compounds. • Mariculture & Yellow River inputs affected antibiotic spatiotemporal distribution. • Veterinary antibiotics showed higher concentrations in summer than in spring. • Priority antibiotics with high ecological and/or resistance risks were identified. [ABSTRACT FROM AUTHOR]

Heavy metal (HM) pollution in coastal ecosystems have posed threats to organisms and human worldwide. This study comprehensively investigated the concentrations, sources, trophodynamics, contamination, and risks of six HMs in the coastal ecosystem of Jiaozhou Bay, northern China, by stable isotope analysis, positive matrix factorization (PMF), and Monte Carlo simulation. Overall, Co, Cu, Ni, Pb, and Zn were significantly bio-diluted in the food web, while Cr was significantly biomagnified with a trophic magnification factor of 1.23. In addition, trophodynamics of the six HMs was different among fish, mollusk, and crustacean. Furthermore, detailed transfer pathways of six HMs in the food web including eight trophic levels were different from one another. Bioaccumulation order of the six HMs was Cu > Zn > Co, Cr, Ni, and Pb. Zinc concentrations were the highest in seawater, sediments, and organisms. Anthropogenic sources contributed to 71% for Zn, 31% for Cu and Pb, and 27% for Co, Cr, and Ni in the sediment, which was moderately contaminated with moderate ecological risk. However, the human health risk of HMs from eating seafood was relatively low. To protect the Jiaozhou Bay ecosystem, HM contamination should be further controlled in future. [Display omitted] • Biodilution/biomagnification of six metals in the Jiaozhou Bay were quantified. • Quantitative trophic transfer pathways of six metals in the bay were identified. • Bioconcentration factors of six metal for eight trophic levels were calculated. • Trophodynamics of six metals was different among fish, mollusk, and crustacean. • Ecological and health risks of six metals in the bay were assessed. [ABSTRACT FROM AUTHOR]

• Increasing trend in vanadium concentrations in aquatic organisms from Asia. • Increases in vanadium concentrations comparable to those from vanadium production. • HC5 for seawater species estimated to be 1.13 (0.05–21.19) μg|L-1. • High and moderate risks to aquatic organisms from seawater concentrations. • Moderate and low health risks from seafood consumption to the 95th percentile group. Vanadium has been classified as a potentially toxic metal and has been given limited attention in comparison to similar trace metals. Similarly, worldwide and continental vanadium pollution and risks remain contested. Here, we synthesized the worldwide concentration of vanadium in marine ecosystems with the relevant ecological and human health risks. We found that vanadium in biota and seawater collected from Asia shows significant increases over the temporal analysis, with rates similar to those reported for vanadium consumption and production. Furthermore, invertebrates have a higher concentration of vanadium than fishes. Similarly, we demonstrate that sediments classified as polluted have concentrations that are not directly correlated with the highest concentrations across continents. Finally, ecological risks were higher from seawater, with potential impacts to 55% of aquatic species in Asia estimated from chronic species sensitivity distribution (SSD). The concentration endangering only 5% of seawater species (HC5) was estimated as 1.13 (0.05–21.19) μg L-1. Estimated daily intakes revealed that overall, there are none to low health risks from aquatic product consumption, yet high risks are plausible to children with consumption patterns in the 95th percentile. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, 26 surface seawater samples, 26 surface sediment samples and 114 organisms were collected to study the trophic transfer and dietary exposure risk of mercury (Hg) in organisms from the Jiaozhou Bay, which is a typical semi-enclosed urbanized bay. The total mercury (THg) and methylmercury (MeHg) concentrations did not exceed the threshold limits and performed as: fish > crustaceans > mollusks. The trophic level values (TLs) were less than 3 in all the groups, indicating simple structure of food chain. With the increasing δ15N value, THg and MeHg were significantly biomagnified in the mollusks and fish but not in the crustaceans. In addition, the bioaccumulation and biomagnification of MeHg were higher than inorganic mercury (IHg) in the aquatic food chain. Target hazard quotient (THQ) and provisional tolerable weekly intake (PTWI) indicated that Hg exposure via consumption of seafood from the Jiaozhou Bay did not pose significant health risks for general population. Consuming fish will face the higher health risk than crustaceans and mollusks, especially in urban regions. Moreover, the risk of MeHg caused by intaking seafood deserved more attention. Trophic transfer function (TTF) explicated the transfer of Hg in the ecosystem and higher trophic transfer efficiency of MeHg than IHg. TTF interpreted the terrestrial input of Hg should be controlled to ensure the safety of consuming seafood from the Jiaozhou Bay. [Display omitted] • Hg concentrations in aquatic samples did not exceed the threshold limit. • Hg biomagnification was observed in marine organisms in the Jiaozhou Bay. • Trophic transfer of MeHg was more obvious than IHg. • Health risk of consuming seafood was more significant in urban regions. • The terrestrial input of Hg should be controlled. [ABSTRACT FROM AUTHOR]

The spatial distributions of atrazine and six types of metabolites in water, suspended particulate sediment (SPS), and surface sediment in an estuary-to-bay system were analyzed. The water distance of metabolites demonstrated that degradation was more active in coastal zone and the Desisopropylatrazine had the shortest half-distance of 1.6 Km from the river mouth. The dechlorination-hydroxylation metabolites were the dominant pollutants in the bay and the Didealkyl-atrazine (DDA), Deisopropylhydroxy-atrazine (DIHA), and Deethylhydroxy-atrazine (DEHA) had higher concentrations in all three mediums. The DDA had the biggest content (6.58 ng/g) in the coastal sediment. The DIHA was the only pollutant had bigger concentration during the transport, and the others continually degraded with smaller value. The spatial distributions of pollutants in sediment had different patterns in water with SPS. The water-particle phase partition coefficient (K p) analysis indicated that the partition process was more active in the estuary than the bay, and the metabolites had stronger capacity than atrazine. The correlations between K p with octanol-water partitioning coefficient showed their physic-chemical properties were the important factors for vertical partition between seawater with sediment. The correlations with marine environmental factors demonstrated that the metabolite type was the direct factor for the redistributions during the transport. [Display omitted] • Spatial patterns of Atrazine and metabolites showed degradation process in estuary-to-bay. • Degraded metabolites had bigger values of seawater and sediment in the bay. • Didealkyl-atrazine had the highest sorption capacity in coastal sediment. • Correlation between Kp with octanol-water coefficient demonstrated the partition process. [ABSTRACT FROM AUTHOR]

Potentially toxic element (PTE) contamination is a common environmental issue in offshore regions worldwide. Water and sediment samples were collected from the Yellow River downstream and adjacent Laizhou Bay to investigate the residues, sources, and ecological risks of 11 typical PTEs (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sc, V, and Zn). The results indicated that the concentrations of PTEs in the sediments decreased from the Yellow River Estuary to the inner Laizhou Bay under the long-term effect of the Yellow River input. Principal component analysis (PCA) identified three potential sources: natural origins, coastal anthropogenic activities (e.g., oil exploration and steel refining), and marine production (e.g., marine aquaculture and transportation). Among the PTEs, Cd was the most significant contaminant, with a contamination factor (CF) of 2.06 ± 0.78. Furthermore, Cd was the most sensitive factor used in evaluating the overall ecological risk using Monte Carlo analysis, with a contribution of up to 96%. Although the overall contamination and risk levels were low in the bay, a higher pollution load index (PLI) and risk index (RI) adjacent to the Yellow River Estuary indicated that the Yellow River remained the primary contributor to the PTEs contamination in the bay. [Display omitted] ● The Yellow River has contributed greatly to PTE accumulation in the Laizhou Bay. ● The sources of PTEs are natural origins, human activities, and marine production. ● A Monte Carlo–Hakanson model was developed to assess the ecological risk of PTEs. ● As a significant contaminant, Cd was the most sensitive factor in risk assessment. ● Generally, the pollution level and ecological risk of PTEs are low in the bay. [ABSTRACT FROM AUTHOR]

• Historical evolution of coastal eutrophication in China exhibited two periods. • Nutrient composition and stoichiometry in coastal waters were significantly changed. • Increased N and P are mainly from river input, atmosphere deposition and SGD. • Changed nutrients have resulted in distinctly varied harmful algal blooms. • Eutrophication combined with climate change continually impact coastal ecosystems. Eutrophication in coastal waters caused by excess nutrient inputs has occurred widely on a global scale. Due to the rapid economic development over the last four decades, most of the Chinese coastal waters have experienced a eutrophic process. Major observed trends of coastal eutrophication include two periods, a slow development from the 1970s to 1990s and a fast development after 2000, with major contributions of increased nitrogen (N) and phosphorus (P) from river inputs, atmospheric deposition, and submarine groundwater discharge (SGD). Nutrient composition and stoichiometry have been significantly changed, including increased ammonium, bioavailable organic N and P, and asymmetric ratios between N, P and silicate (Si). Most of these changes were related to the rapid increases in population density, fertilizer application, sewage discharge, aquaculture and fossil fuel combustion, and have resulted in distinctly increased harmful algal blooms. Coastal eutrophication combined with the effects of climate change is projected to continually grow in coming decades. Targeted research is therefore needed on nitrogen reduction and control, potential adaptation strategies and the consequences for ecosystems and economic sustainability. [ABSTRACT FROM AUTHOR]