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Background and aimsMany agricultural areas are expected to face hotter, drier conditions from climate change. Understanding the mechanisms that crops use to mitigate these stresses can guide breeding for more tolerant plant material. We tested relationships between traits, physiological function in hot conditions and historical climate associations to evaluate these mechanisms for winegrapes. We expected a more negative leaf osmotic potential at full hydration (πo), which reduces leaf turgor loss during drought, and either a metabolically cheaper or more osmoprotectant leaf chemical composition, to allow cultivars associated with hot, dry regions to maintain greater gas exchange in hot growing conditions.MethodsWe measured πo, gas exchange and leaf chemistry for seven commercially important winegrape cultivars that vary widely in historical climate associations. Vines were grown in common-garden field conditions in a hot wine-growing region (Davis, CA, USA) and measured over the hottest period of the growing season (July-September).Key resultsThe value of πo varied significantly between cultivars, and all cultivars significantly reduced πo (osmotically adjusted) over the study period, although osmotic adjustment did not vary across cultivars. The value of πo was correlated with gas exchange and climate associations, but in the direction opposite to expected. Photosynthesis and πo were higher in the cultivars associated with hotter, less humid regions. Leaf chemical composition varied between cultivars but was not related to climate associations.ConclusionsThese findings suggest that maintenance of leaf turgor is not a primary limitation on grapevine adaptation to hot or atmospherically dry growing conditions. Thus, selecting for a more negative πo or greater osmotic adjustment is not a promising strategy to develop more climate-resilient grape varieties, contrary to findings for other crops. Future work is needed to identify the mechanisms increasing photosynthesis in the cultivars associated with hot, dry regions.

Critical seagrass ecosystems are predicted to be impacted by droughts and floods of increasing severity and frequency as the climate changes. Hyposalinity events alter seagrass composition and challenge resilience, yet understanding of the response mechanisms is incomplete but necessary for predicting outcomes. Hyposalinity stress response mechanisms in Halodule wrightii (shoal grass), a seagrass with wide salinity tolerance, were examined in mesocosm experiments by measuring monovalent and divalent ions, free amino acid (FAA) concentrations, and the Thiobarbituric Acid Reactive Substances (TBARS) indicator of lipid peroxidation. Two progressive, 3-step treatments, to moderate and extreme hyposalinity endpoints S15 and S5 were compared. Concentrations of Na+, K+, Ca2+, and Cl− decreased two to threefold with greater hyposalinity. Proline, the most abundant FAA initially, progressively decreased with increasing hyposalinity as asparagine became dominant. Glutamine and serine increased significantly, and all four FAA exhibited consistent patterns of change. Results are consistent with proline's role as osmolyte and regulator, and suggest that asparagine mobilizes or stores N, possibly due to another limiting nutrient. TBARS changed transiently at intermediate salinities, but were not significantly different at hyposalinity endpoints indicating that H. wrightii may have already reached stress equilibrium. Prolonged hyposalinity events may have consequences for seagrass resilience. [ABSTRACT FROM AUTHOR]

Pharmaceutically active compounds (PhACs) are widely used in medical treatments but pose risks to ecosystems and human health when present in the environment. Understanding their fate in nature is complex and influenced by various factors. Phototransformation, where PhACs change chemically upon light exposure, offers the potential for reducing their environmental levels. Studying this process is crucial for understanding risks, developing safe disposal strategies, and innovating removal methods to mitigate adverse effects. This review delves into the major factors influencing the transformation of PhACs under natural conditions. It provides a comprehensive analysis of the mechanisms involved in the photochemical activity of PhACs, shedding light on their behavior upon exposure to sunlight. Special attention is given to delineating the differences in the phototransformation processes among 13 major pharmaceutical classes. By examining the various factors influencing PhAC transformation and elucidating their mechanisms, this review aims to contribute to a deeper understanding of the fate of pharmaceuticals in the environment. Such insights are invaluable for developing effective strategies to mitigate the risks posed by PhAC contamination and safeguarding environmental and human health.

Although numerous studies have been carried out to study haze formation in the North China Plain (NCP) and Northeastern Plain (NP), little is known about the chemical compositions and haze formations in Qinhuangdao city, which is located in the northeast edge of the NCP and adjacent to the NP. In this study, water‐soluble inorganic ions, organic carbon and elemental carbon (EC) were analysed offline during two haze periods from October 29 to November 7, 2021. The results showed that NO3− and organic matter (OM) accounted for 34.81% and 21.15% of total PM2.5 mass concentration, respectively, followed by NH4+ (14.06%) and SO42− (12.33%). The sulphur oxidation ratio and nitrogen oxidation ratio as well as OM/EC ratio on haze days were higher than those on non‐haze days, suggesting both high secondary inorganic and organic aerosol formation on haze days under high relative humidity. Source apportionment results showed that marine aerosols contributed small of total aerosol particle loads, while the combustion‐related sources were the most, possibly coal combustion, biomass burning and vehicle emissions. Air masses during haze periods mainly came from southwest and west directions in this case. Further calculated meteorological data of 2018–2021 showed high PM2.5 mass in Qinhuangdao were mainly affected by low‐speed southwest wind in autumn. The results highlighted the important role of long‐range transport of air pollutants from the NCP instead of the NP on haze formation in autumn in Qinhuangdao. [ABSTRACT FROM AUTHOR]

The effect of short-term and long-term root treatment with melatonin on growth parameters, photochemical activity of PSII, content of basic photosynthetic pigments, lipid peroxidation, and accumulation of inorganic ions in barley plants under the action of cadmium chloride was studied. It was shown for the first time that the protective effect of phytomelatonin during short-term treatment is manifested in a decrease in the toxic effect of cadmium on the content of photosynthetic pigments and the accumulation of cadmium ions in the shoots and roots of barley plants. The protective effect of melatonin is based on its ability to reduce the intensity of oxidative stress by maintaining the level of carotenoids and increasing the activity of antioxidant enzymes. The effectiveness of short-term use of melatonin in a number of indicators exceeds its protective effect from long-term exposure. The data obtained indicate the possibility of using melatonin as a substance that induces the state of plant priming upon subsequent exposure to cadmium. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing facilitates the development and exploitation of unconventional reservoirs. In this study, the injected hydraulic fracturing fluid (HFF) and flowback and produced water (FPW) in tight oil reservoirs of the Lucaogou Formation in the Junggar Basin are temporally sampled from day 1 to day 64. Freshwater is used for fracturing, and HFF is obtained. The chemical and isotopic parameters (including the water type, total salinity, total dissolved solids (TDS), pH, concentrations of Na+, Cl−, Ba+, K+, Fe2+ + Fe3+, and CO32−, δD, and δ18O) are experimentally obtained, and their variations with time are systematically analyzed based on the flowback water. The results show that the water type, Na/Cl ratio, total salinity, and TDS of the FPW change periodically primarily due to the HFF mixing with formation water, thus causing δD and δ18O to deviate from the meteoric water line of Xinjiang. Because of water–rock interaction (WRI), the concentrations of Fe2+ + Fe3+and CO32− of the FPW increase over time, with the solution pH becoming more alkaline. Furthermore, based on the significant changes observed in the geochemistry of the FPW, three separate time intervals of flowback time are identified: Stage I (< 10 days), where the FPW is dominated by the HFF and the changes in ions and isotopes are mainly caused by the WRI; Stage II (10–37 days), where the FPW is dominated by the addition of formation water to the HFF and the WRI is weakened; and finally, Stage III (> 37 days), where the FPW is dominated by the chemistry of the formation water. The methodology implemented in this study can provide critical support for the source identification of formation water. [ABSTRACT FROM AUTHOR]

Every day, more and more consumers choose to drink bottled water instead of tap water, since they believe that it is superior in quality. One of the criteria used by European consumers to choose bottled water is the geographical region of the spring. The flavor of the water is an additional factor that influences consumers’ choices. As a result, determining the flavor of water is gaining popularity and is thus turning into a prominent field of study. However, studies on the potential environmental factors that affect the sensory characteristics of water (i.e., “terroir” of water) are limited. To this end, we investigated the composition of natural mineral water spring from Mount Smolikas in Greece over a two-year period to find any potential alterations in water composition. The physicochemical parameters (pH, conductivity, turbidity, color, and total hardness) of the water samples were examined, along with their content in metal ions, inorganic salts (cations and anions), and total organic carbon. Additionally, the water samples were analyzed for their content of off-odor volatile compounds (i.e., 2-methylisoborneol and geosmin) that can be naturally found in water. The study also examined the correlation of climate conditions (accumulated rainfall and mean temperature) with the parameters above using a principal component analysis and a multivariate correlation analysis. The results showed that the physicochemical characteristics of water samples complied with European regulations. Metals, anions, and cations were all below the corresponding parametric values established by the European Commission. The off-odor organic compounds, 2-methylisoborneol, and geosmin, had average concentrations of 9.4 and 2.7 ng/L, respectively. Chromium and aluminum elevated concentrations might be attributed to specific ores present near the water source, while pH, conductivity, total hardness, nitrates, and off-odor compounds levels could be fluctuated due to local climate conditions. The study revealed a good positive correlation (>0.7) between the quantity of rainfall and the level of potassium cations. Moreover, a strong negative correlation (>0.9) was observed between magnesium cations and the mean temperature of the local area. The study can be used as a benchmark for future studies to determine the terroir of mineral water.

Every day, more and more consumers choose to drink bottled water instead of tap water, since they believe that it is superior in quality. One of the criteria used by European consumers to choose bottled water is the geographical region of the spring. The flavor of the water is an additional factor that influences consumers' choices. As a result, determining the flavor of water is gaining popularity and is thus turning into a prominent field of study. However, studies on the potential environmental factors that affect the sensory characteristics of water (i.e., "terroir" of water) are limited. To this end, we investigated the composition of natural mineral water spring from Mount Smolikas in Greece over a two-year period to find any potential alterations in water composition. The physicochemical parameters (pH, conductivity, turbidity, color, and total hardness) of the water samples were examined, along with their content in metal ions, inorganic salts (cations and anions), and total organic carbon. Additionally, the water samples were analyzed for their content of off-odor volatile compounds (i.e., 2-methylisoborneol and geosmin) that can be naturally found in water. The study also examined the correlation of climate conditions (accumulated rainfall and mean temperature) with the parameters above using a principal component analysis and a multivariate correlation analysis. The results showed that the physicochemical characteristics of water samples complied with European regulations. Metals, anions, and cations were all below the corresponding parametric values established by the European Commission. The off-odor organic compounds, 2-methylisoborneol, and geosmin, had average concentrations of 9.4 and 2.7 ng/L, respectively. Chromium and aluminum elevated concentrations might be attributed to specific ores present near the water source, while pH, conductivity, total hardness, nitrates, and off-odor compounds levels could be fluctuated due to local climate conditions. The study revealed a good positive correlation (>0.7) between the quantity of rainfall and the level of potassium cations. Moreover, a strong negative correlation (>0.9) was observed between magnesium cations and the mean temperature of the local area. The study can be used as a benchmark for future studies to determine the terroir of mineral water. [ABSTRACT FROM AUTHOR]

Objectives: To compare the microhardness and ion content of three glass-ionomer cements (GICs) during setting and up to 15 days, to composite resin-based material in vitro, and after 5 to 10 years in vivo. Method and materials: Disks of three GICs, EQUIA Fil, Riva Self Cure, and Ketac Molar were examined in vitro for microhardness using Vickers indentations after 15 to 60 minutes, 24 hours, and 8 and 15 days, and compared to composite material, Spectrum. The ion content of the GIC and composite was analyzed using the energy dispersive spectroscopy program of a scanning electron microscope. A primary second molar restored with GIC normally exfoliated after 5 years, and a third molar restored with GIC extracted due to periodontitis after 10 years, were sliced through the restoration buccolingually, and the microhardness of the restoration and of the dentin was measured. Results: In comparison to composite material, the Vickers value for the GICs were similar or better after 24 hours to 15 days. The amount of fluorine was three times higher in EQUIA Fil and Riva Self Cure in comparison with Ketac Molar, after 20 days. After 5 years in vivo, the microhardness of GICs was similar to dentin and after 10 years it was significantly higher than that of the dentin. Conclusion: The microhardness of GICs was comparable to composite material after only 24 hours. In vivo the microhardness of GICs increased and after 10 years in vivo it was higher than that of the dentin. After 20 days the amount of fluorine was still high in Riva Self Cure and EQUIA Fil. [ABSTRACT FROM AUTHOR]

Size distributions of chemical species provide evidence for their sources and formation mechanisms. Size‐segregated aerosols with 12 sizes were collected over Northern Japan (Sapporo: 43.07°N and 141.35°E) during the spring (9 April–21 May) of 2001 and analyzed for water‐soluble organic and inorganic species. The dominances of SO42– and NH4+ in submicron (Da < 1.1 μm) and Na+ and Ca2+ in supermicron (Da > 1.1 μm) aerosols suggest substantial contributions from anthropogenic sources, sea‐salt and dust particles via long‐range atmospheric transport. Oxalic acid (C2) is the dominant organic species followed by malonic (C3) and succinic (C4) acid. A supermicron mode enrichment of C2 is heavily involved with the long‐range transport of dust particles, whereas submicron mode C2 was influenced by anthropogenic sources from the East Asian continent. The size distributions of shorter‐chain diacids (C3–C6), phthalic (Ph) and glyoxylic acid are consistent with those of C2, whereas azelaic acid (C9) is enriched in submicron and supermicron modes by the influences of continental and marine air masses. The mass concentration ratios of C3/C4 in submicron (1.5–2.3) and supermicron (1.2–1.8) mode demonstrated that water‐soluble organic aerosols in Sapporo were photochemically processed during long‐range transport. The Ph/C9 ratios show that the influence of anthropogenic sources on 9–28 April samples was pronounced in supermicron (2.5–2.9) than the submicron (1.1–1.2) particles, and vice‐versa on 6–21 May samples. These contrast distributions suggest that the continental air masses from East Asia and marine air masses from the surrounding ocean likely control the chemical composition of aerosols over Northern Japan. Plain Language Summary: Dicarboxylic acids make up a considerable portion of water‐soluble organic aerosols (OAs) in the atmosphere. We present the changes in the size distributions of water‐soluble secondary OAs during the ACE‐Asia campaign in the spring of 2001 in Northern Japan. The molecular distribution of dicarboxylic acids in size‐segregated aerosols with a predominance of oxalic acid (C2) followed by malonic acid implies that water‐soluble OAs over Northern Japan were photochemically aged. The substantial fraction of C2 on the supermicron mode aerosols is affected by the dust transported from the East Asian continent, suggesting its uptake or heterogeneous production on the surface of dust particles during long‐range transport to Northern Japan. Significant positive correlations of C2 and related compounds with Ca2+ in a supermicron mode further support a heterogeneous production of C2 in Ca2+‐enriched supermicron aerosols. The results suggest that the air masses from East Asia and the surrounding ocean mainly control the abundances of OAs over Northern Japan. The atmospheric abundance of secondary OAs could change due to the enhanced production of C2 in supermicron and submicron particles that can affect aerosol‐cloud interaction and radiative forcing of the most considerable fraction of water‐soluble secondary OAs. Key Points: The chemical composition of atmospheric aerosols over Northern Japan is controlled by continental and marine air massesOxalic acid size distribution is induced by the long‐range transport of dust particles and anthropogenic sourcesWater‐soluble organic aerosols over Northern Japan were photochemically processed during long‐range atmospheric transport [ABSTRACT FROM AUTHOR]

Photocatalytic degradation is an effective technique for removing dyes from contaminated water. Herein, a nanocomposite that contains banana peel activated carbon and nanoparticles of zinc oxide (BPAC/ZnO) was prepared by the physical mixing method. The impact of inorganic anions (Cl−, HCO3–, NO3−, and F−) and cations (Al3+ and Ca2+) at different concentrations (2, 10, 30 mM) was examined. This work investigates the incorporation of ZnO nanoparticles onto activated carbon in order to enhance the photocatalytic degradation of Acid Blue 25 (AB25). Under the optimum conditions of effective parameters, the effect of different scavengers (EDTA, ethanol, KI, NaN3, Na2S2O8, NaBrO3, H2O2, and BQ) at various concentrations (2, 10, and 30 mM) was investigated. The results showed that h+ and O2·− play a pivotal role in the Acid Blue 25 removal. Also, it should be noted that hydroxyl radicals play a supplementary role in the photocatalytic degradation of Acid Blue 25. Also, electron scavengers, including Na2S2O8 and NaBrO3, increased the degradation rate. Among the anions, NO3− exhibited the strongest inhibition potential. Inorganic anions inhibited the photocatalytic removal of AB25 in the following order N O 3 _ ≥ F _ ≥ H C O 3 - ≥ C l _ . Likewise, Al3+ showed the highest inhibition among cations. [ABSTRACT FROM AUTHOR]

The quality of groundwater has been severely impacted by urbanization around coasts. The change in climate and land use patterns has deteriorated the quality and availability of groundwater. One of the main issues in contemporary groundwater quality research is dissolved organic carbon (DOC) in the water. The influence of DO, water level and water temperature on DOC in groundwater was identified in the current study by sampling 68 groundwater samples. The analytical results revealed that ~18% of total samples have DOC > 5 mg/L. The groundwater samples represented in the urban regions show high DOC. The samples with higher DOC correlated positively with dissolved inorganic ions, such as Ca, K, NO3, Fe and DO. Domestic wastewater, agricultural runoff and local geology all have an impact on the DOC of groundwater. Groundwater chemistry is shown to be controlled by both aerobic and anaerobic conditions based on the DOC's interactions with other ions. The study interrelates various sources, such as land use, geology, water level and temperature, to the DOC in groundwater and infers that the levels are higher in shallow groundwater, predominantly around the built-up region followed by the agricultural region. The temperature changes enhance the DOC in groundwater due to the variation in microbial activity. The shallow water level with a lower temperature shows the maximum DOC. Apart from the sediment organic matter and microbes, the study also attributes land use pattern to the source of DOC in groundwater. [ABSTRACT FROM AUTHOR]

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Ecological water replenishment is considered to be an important project to adjust river ecosystems with water shortages and degradation, and its impact on the water quality of the target river section deserves attention. By investigating the characteristics of inorganic ions and organic components of the Beijing section of the Yongding River (YDR) from upstream to downstream, the sources of inorganic ions and dissolved organic matter (DOM) during an ecological water replenishment event were analysed and discussed. This study illustrated the hydrochemical response to different supplemental water sources in three sections of the YDR (mountain gorge section (MGS), urban plain section (UPS), and suburb plain section (SPS)). The results showed that the total dissolved solids (TDS) and ion concentrations were significantly different (p < 0.001) in the three river sections due to different supplemental water sources. The highest concentration of TDS was found in the UPS (870.92 mg/L) replenished by reclaimed water, while the lowest concentration of TDS was found in the SPS (306.95 mg/L) replenished by the water of the South-to-North Water Diversion Project (SNWD). Despite the differences in the water sources of replenishment, the optical parameters of DOM and fluorescent components showed similar protein-like dominated endogenous source characteristics in the three river sections of the YDR, which was due to the influence of reservoir water (MGS and SPS) and reclaimed water (UPS). Our study emphasizes the importance of understanding the impact of different water sources on the water replenishment process, which provides a scientific reference for the management of ecological water replenishment. [ABSTRACT FROM AUTHOR]

Humin (HM) is the main organic matter component to affect the migration and transformation of polycyclic aromatic hydrocarbons (PAHs) in soil. The study on influence of the morphology change of inorganic ions on the adsorption of PAHs in soil and its organic matter is still rare at microscopic scale. In this paper, yellow soil humin (YS-HM) and lime soil humin (LS-HM) were chosen as samples, then Fe3+ and Ca2+ were added into samples to facilitate the precipitation by changing the existing conditions of ions, and the mechanism by which inorganic precipitation changed adsorption capacity of karst soil was analyzed from the microscopic scale. The results showed that the adsorption capacity of HM reduced with the inorganic precipitation increasing. The precipitation of Ca2+ and Fe3+ both reduced the adsorption capacity of YS-HM and LS-HM by 61.71% and 71.83% on average, respectively. The results of scanning electron microscope-energy dispersive spectrometry (SEM-EDS) and pore analysis showed that the HM porosity decreased after formation of Ca2+ and Fe3+ precipitation. According to the value of Freundlich parameter n, it may be because the precipitation or colloid of Ca2+ and Fe3+ filled micropores and covers high-energy adsorption sites of the HM. This research provides theoretical support for studying the PAHs migration and bioavailability of Calcium-rich in karst soil. [ABSTRACT FROM AUTHOR]

In the present paper, the influence of iodate (IO3−) ions on the photocatalytic process using titanium dioxide (UV/TiO2) was systematically examined. The innovative studied system (UV/TiO2/IO3−) demonstrated high performance in the elimination of safranin O (SO), a model dye, from water due to the implication of iodine radicals (IO3•, IO2•, IO•, etc.). The degradation was assessed by monitoring the change in initial substrate concentration (5–30 mg∙L−1), TiO2 loading (0.01–3 g∙L−1), IO3− concentration, liquid temperature, and initial pH. Further enhancement of oxyanion amount was beneficial for the initial rate of degradation (r0) over the range 0.1–50 mM, such that r0 rose from 0.724 to 1.12 mg∙L−1∙min−1. However, a concentration of 100 mM IO3− slowed the removal kinetics. Low pH values were found to be favorable for pollutant removal. Furthermore, a variety of inorganic and organic substances was employed to clarify the effect of the UV/TiO2/IO3− process in natural waters. The findings revealed a negative impact of chloride excess in seawater and a decline in SO degradation in mineral water as a result of HCO3− presence at more than 1 mM. At high concentrations of natural organic matter, the heterogeneity and the strong adsorption of humic acid on the TiO2 surface were found to be harmful for SO decay. [ABSTRACT FROM AUTHOR]

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future. [ABSTRACT FROM AUTHOR]

Cornus florida and Cornus hongkongensis subsp. elegans are potential species in saline-alkali areas for use as horticultural plants with high ornamental value. This work aimed to screen suitable tolerant dogwoods by comparing the responses of two dogwoods to salt stress according to phenotypic and physiochemical indicators on germination and seedling growth. For relieving seed dormancy, two pretreatments were performed on seeds, coded as T1 (soaked by gibberellic acid (GA3) alone) and T2 (soaked by GA3 with gradient salt concentrations of 0.2%, 0.3%, 0.4%, and 0.45%), and pretreated seeds were then germinated at the corresponding salt concentrations in pretreatment. As salt levels increased, the seed germination parameters decreased for both dogwoods, whereas the relative salt damage rate (SDR) significantly increased. While the growth of above-ground parts was significantly inhibited, that of underground parts changed little. Furthermore, the malondialdehyde content (MDA), superoxide dismutase activity (SOD), organic solutes (soluble sugar (SS) and proline (Pro)), and inorganic ions (K+, Na+, Ca2+) significantly accumulated in seedlings with increasing salinity levels, whereas K+/Na+ ratio decreased. Correlation analysis indicates that organic osmolyte (SS) and ion osmoregulation could be the main physiological mechanisms conferring salinity tolerance for both dogwoods. Compared with osmolytes, ion osmoregulation may be more critical for salt tolerance in the seedlings of the studied dogwoods. Collectively, the superior salt tolerance of C. florida to C. hongkongensis subsp. elegans suggests that the two species could be cultivated in saline areas with 0.3% and 0.2% salt levels, respectively. [ABSTRACT FROM AUTHOR]

N-Nitrosamines, well-known human carcinogens, are widely considered to be formed through the disinfection of waters containing compounds with amine moieties. The formation mechanisms of nitrosamines during the disinfection of drinking water and wastewater have been previously reviewed in the literature. However, no study to date has reviewed the effects of inorganic ions on nitrosamines formation during disinfection. Inorganic ions are ubiquitous in the environment and are present at significant concentrations in water and wastewater. Their presence influences aqueous nitrosamines formation, depending on the type, concentration, and environmental conditions. In this review, we have critically reviewed nitrosamines' precursors and occurrence, disinfection processes associated with nitrosamines' formation/destruction, and the impact of inorganic ions on the formation or removal of nitrosamines during disinfection of water and wastewater. The disinfectants reviewed in the study were chlorine, chloramine, chlorine dioxide, ozone, and radicals generated through advanced oxidation processes (AOPs). N-Nitrosodimethylamine formation pathways, in the presence and absence of inorganic ions, were also reviewed to summarize our current understanding. Although chloramination has been associated with the formation of nitrosamines, many ozonation studies have also shown significant levels of nitrosamines formation. Pre-oxidation and AOPs have been reported as the most promising mitigation strategies for controlling nitrosamines formation, requiring prolonged exposure of precursors for effective mineralization. [ABSTRACT FROM AUTHOR]

In sediments, cadmium (Cd) contamination is an increasingly severe global problem facing environmental protection and human health. The mobility and biological toxicity of Cd are related to its chemical fractions. In this work, the European Community Bureau of Reference (BCR) sequential extraction procedure and inductively coupled plasma optical emission spectrometry (ICP-OES) technology were integrated to identify the effect of grain size, pH, organic acids, inorganic anions, and cations on the chemical fractions of Cd in sediments. The result indicated that the sediments with the fine grain (< 63 μm) presented a good ability to combine Cd, while the coarse grains (> 250 μm) exhibited a more exchangeable/acid-soluble fraction (78.14 wt%). Besides, the amount of Cd released from the sediment decreased dramatically with pH from 2 to 6 and leveled off in the pH range of 8–10. The more mobile fractions (exchangeable/acid-soluble fraction (F1) and reducible fraction (F2)) were significantly affected by pH, implying that pH was an important factor influencing the release of Cd into the upper water environment. For organic acids, which mainly affect the release of Cd in the exchangeable and carbonate-bound fraction, the influence of organic acid on the mobility of Cd in sediments followed the order: ethylenediaminetetraacetate acid (EDTA) > citric acid (CA) > tartaric acid (TA) > oxalic acid (OA). The impact of SO42−, Cl−, CO32−, NO3−, Ca(II) and Mg(II) was not evident in the release of Cd from the sediment, while Al(III) and Fe(III) had a greater effect on the chemical fraction of Cd. The study outcomes provide fundamental knowledge for understanding the potential mobility of Cd in sediment. [ABSTRACT FROM AUTHOR]

• Optimal magnetization parameters for various inorganic salt solutions were confirmed. • The effect of ions on hydrogen bonding corresponds to their wettability to coal. • Na+ and Cl– promote hydrogen bond breaking and improve solution wettability. • Mg2+, Ca2+, CO 3 2– and SO 4 2– all make magnetization less effective. Coal dust is a significant problem in underground coal mining, and more economical and effective methods are needed to control coal dust. Magnetized water dust removal technology is considered to be an effective method to solve the problem of high concentration dust. In order to further understand the role of ions in magnetic fields in water, the optimal magnetic field parameters for solutions containing various ions were determined by surface tension and contact angle measurements. The wettability experiments have shown that the optimal magnetization effect can be obtained by placing NaCl solution with the concentration of 0.04 mol/L in the 150mT magnetic field for 120 s at room temperature. Subsequently, the influence of various ions in water on the wettability of coal was investigated using a combination of FTIR testing and Zeta potential experiments. The results showed that the order of the influence intensity of different ions on the wettability of water was Na+ > Mg2+ > Ca2+ when the Cl– content was 0.04 mol/l, and Cl– > CO 3 2– > SO 4 2– when the Na+ content was 0.04 mol/L. Furthermore, Lorentz forces can influence various ions, accelerating their migration and enhancing their accessibility to water clusters. Different ions exert force on the dipoles within water molecules, which can promote or suppress hydrogen bond cleavage. When the number of hydrogen bond breaks rises, it leads to an increase in the wetting properties of the solution. The research findings provide a theoretical foundation for the use of magnetization technology in dust suppression with mist spray in underground coal mines. [ABSTRACT FROM AUTHOR]

Electromembrane extraction (EME) is a miniaturized extraction technique that has been widely used in recent years for the analysis and removal of pollutants in the environment. It is based on electrokinetic migration across a supported liquid membrane (SLM) under the influence of an external electrical field between two aqueous compartments. Based on the features of the SLM and the electrical field, EME offers quick extraction, effective sample clean-up, and good selectivity, and limits the amount of organic solvent used per sample to a few microliters. In this paper, the basic devices (membrane materials and types of organic solvents) and influencing factors of EME are first introduced, and the applications of EME in the analysis and removal of environmental inorganic ions and organic pollutants are systematically reviewed. An outlook on the future development of EME for environmental applications is also given.

Nitrogen application could alleviate salt stress on crops, but the specific physiological mechanism is still unclear. Therefore, in this study, a pot experiment was conducted to explore the effects of different application rates of nitrogen (0, 0.15, 0.30, and 0.45 g·kg−1) on the growth parameters, osmotic adjustment, reactive oxygen species scavenging, and photosynthesis of rapeseed seedlings planted in the soils with different concentrations of sodium chloride (1.5, 3.5, 5.5, and 7.5 g·kg−1). The results showed that nitrogen could alleviate the inhibition of salt on rapeseed growth, and improve the antioxidant enzyme activities and the contents of non-enzymatic substances, K+, soluble protein (SP), soluble sugar (SS), and proline. Besides, there was a significant correlation between the indexes of active oxygen scavenging system, osmoregulation system, and photosynthesis. Therefore, applying appropriate amount of nitrogen can promote the growth and development of rapeseed seedlings under salt stress, accelerate the scavenging of reactive oxygen species, maintain osmotic balance, and promote photosynthesis. This study will improve our understanding on the mechanism by which nitrogen application alleviates salt stress to crops.

Floral nectar contains mainly sugars as well as smaller amounts of amino acids and further compounds. The nectar composition varies between different plant species and it is related to the pollination type of the plant. In addition to this, other factors can influence the composition. Nectar is produced in and secreted from nectaries. A few models exist to explain the origin of nectar for dicotyl plant species, a complete elucidation of the processes, however, has not yet been achieved. This is particularly true for monocots or plant species with CAM photosynthesis. To get closer to such an elucidation, nectar, nectaries, and leaves of 36 bromeliad species were analyzed for sugars, starch, amino acids, and inorganic ions. The species studied include different photosynthesis types (CAM/C3), different pollination types (trochilophilous/chiropterophilous), or different live forms. The main sugars in nectar and nectaries were glucose, fructose, and sucrose, the total sugar concentration was about twofold higher in nectar than in nectaries, which suggests that sugars are actively transported from the nectaries into the nectar. The composition of amino acids in nectar is already determined in the nectaries, but the concentration is much lower in nectar than in nectaries, which suggests selective retention of amino acids during nectar secretion. The same applies to inorganic ions. Statistical analyses showed that the photosynthesis type and the pollination type can explain more data variation in nectar than in nectaries and leaves. Furthermore, the pollinator type has a stronger influence on the nectar or nectary composition than the photosynthesis type. Trochilophilous C3 plants showed significant correlations between the nitrate concentration in leaves and the amino acid concentration in nectaries and nectar. It can be assumed that the more nitrate is taken up, the more amino acids are synthesized in leaves and transported to the nectaries and nectar. However, chiropterophilous C3 plants show no such correlation, which means that the secretion of amino acids into the nectar is regulated by further factors. The results help understand the physiological properties that influence nectaries and nectar as well as the manner of metabolite and ion secretion from nectaries to nectar. [ABSTRACT FROM AUTHOR]

A new, simple and sensitive ion chromatography (IC) method for the determination of sodium, potassium, magnesium, calcium and chloride in a parenteral nutrition (PN) solution was developed and validated. Before sample analysis, a sample pretreatment by calcination was applied which could totally remove interference from other constituents of the PN solution. Methanesulfonic acid (MSA) and sodium hydroxide were used as the mobile phase for the determination of cations and anions, respectively. The calibration curves showed good correlation between analyte peak area and concentration (r2 > 0.999). Detection limits ranged from 0.0001 to 0.02 mg/L and quantification limits from 0.0002 to 0.06 mg/L. Relative standard deviation (RSD) values for repeatability and inter-day precision did not exceed 1.0% and the recoveries for all analytes were between 99.1–101.1%. The robustness was verified by using an experimental design. [ABSTRACT FROM AUTHOR]

A promising strategy for sustainably increasing the quality and yield of horticultural products is the use of natural plant biostimulants. In this work, through a greenhouse experiment, we evaluated the effect of a legume-derived biostimulant at three dose treatments (0.0 control, 2.5 mL L−1, and 5.0 mL L−1) on the yield performance, nutrients traits, leaf anatomical traits, gas exchanges, and carbon photosynthetic assimilation of greenhouse lettuce. The lettuce plants were foliar sprayed every 7 days for 5 weeks. The application of plant biostimulant, at both lower and higher dosages, increased the nutrient use efficiency, root dry weight, and leaf area. However, it is noteworthy that the 5.0 mL L−1 dose enhanced photosynthetic activity in the early phase of growth (15 DAT), thus supplying carbon skeletons useful for increasing the number of leaves and their efficiency (higher SPAD), and for boosting nutrient uptake (P, S, and K) and transport to leaves, while the 2.5 mL L−1 dose exerted specific effects on roots, increasing their dimension and enabling them to better use nitrate and Ca. A higher dose of biostimulant application might find its way in shorter growing cycle, thus presenting new horizons for new lines of research in baby leaves production. [ABSTRACT FROM AUTHOR]

Particulate matter (PM) emission has been widely concerned all over the world. The formation of condensable particulate matter (CPM) was affected by atmospheric temperature. An optimal-designed sampling device and monitoring method for particulate matter in high-humidity flue gas were applied to the particulate matter emission concentration of 12 ultra-low emission coal-fired units. The emission levels and composition characteristics of particulate matter and main inorganic ions in the flue gas were analyzed and evaluated. The results showed that the filterable particulate matter (FPM) concentration range was 0.81–7.52 mg/m3, and the condensable particulate matter concentration range was 1.10–12.25 mg/m3. The emission characteristics of CPM/FPM was significantly affected by different air pollution control devices. Preferable emission reduction result of condensable particulate matter may be realized by units equipping wet limestone-gypsum flue gas desulfurization and wet electrostatic precipitator. The certain correlation was showed between CPM/FPM and ash content. The inorganic ion concentration range was 1104–8240 μg/m3 in condensable particulate matter. Ca2+ concentration accounted for more than 45% of the cation concentration, and SO42− concentration accounted for up to 97.81% of the anion concentration in CPM.

The quality of groundwater has been severely impacted by urbanization around coasts. The change in climate and land use patterns has deteriorated the quality and availability of groundwater. One of the main issues in contemporary groundwater quality research is dissolved organic carbon (DOC) in the water. The influence of DO, water level and water temperature on DOC in groundwater was identified in the current study by sampling 68 groundwater samples. The analytical results revealed that ~18% of total samples have DOC > 5 mg/L. The groundwater samples represented in the urban regions show high DOC. The samples with higher DOC correlated positively with dissolved inorganic ions, such as Ca, K, NO3, Fe and DO. Domestic wastewater, agricultural runoff and local geology all have an impact on the DOC of groundwater. Groundwater chemistry is shown to be controlled by both aerobic and anaerobic conditions based on the DOC’s interactions with other ions. The study interrelates various sources, such as land use, geology, water level and temperature, to the DOC in groundwater and infers that the levels are higher in shallow groundwater, predominantly around the built-up region followed by the agricultural region. The temperature changes enhance the DOC in groundwater due to the variation in microbial activity. The shallow water level with a lower temperature shows the maximum DOC. Apart from the sediment organic matter and microbes, the study also attributes land use pattern to the source of DOC in groundwater.

This study focused on the characteristics, distribution, and source of inorganic ions in segmented precipitation of Nanchang. The method of segmented collection of precipitation samples, previously established by our research group, was adopted. From May to September 2020, 20 precipitation events were investigated. A total of 88 segmented precipitation samples were collected, and Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO2−, NO3−, and SO42− were determined. The concentrations of these ions in segmented precipitation samples decreased generally from the first to the sub-last segment and frequently increased from the sub-last to the last segment, indicating that the ions of the early segmented precipitation were mainly derived from air pollutants and those of the last segmented precipitation from cloud water and washed condensed particles. Both Ca2+ and NH4+ were dominant cations, whereas NO3− and SO42− were the dominant anions. The concentrations of Ca2+, NH4+, NO3−, and SO42− in precipitation of Nanchang were medium, reflecting moderate air pollution. The correlations between two of Na+, NH4+, K+, Cl−, NO2−, NO3−, and SO42− in the first two segmented precipitation samples were slightly weaker than those in the last two segmented precipitation samples, indicating contribution both from below-cloud and in-cloud scavenging in early precipitation and from cloud water in late precipitation. The contribution of below-cloud scavenging to major ions in precipitation decreased gradually, and conversely, the contribution of in-cloud scavenging to ions in precipitation increased gradually. [ABSTRACT FROM AUTHOR]

• Zeolites are cost-effective material with no reported harm to agricultural farms and underground water. • Foliar application of SA (1 mM) and soil application of Ze (8g/ kg) had positive effects on water-deficit stress tolerance of wheat plants. • Exogenous application of salicylic acid and zeolite increased APX, POD and CAT activities as well as grain number and grain yield. • The beneficial influence of SA and Ze (8 g/kg) were also observed in control plants grown in well-watered condition. With the prevalence of water scarcity and a growing demand for food, it is imperative to utilize inexpensive and environmentally friendly materials such as zeolite (Ze) and salicylic acid (SA) in agricultural farms. In this regard, in the present study we measured the effects of exogenous application of Ze (4 g/kg soil and 8 g/kg soil) and SA (1 mM) on wheat plants Cv. Sirvan in both normal (100% FC) and drought stress (40% FC) conditions. The study measured several physiological, biochemical and morphological characteristics, including antioxidant enzyme activities (POD, CAT, APX), soluble sugar, soluble protein, inorganic ions (K+, Ca2+, and Mg2+), grain number and grain yield. SA and Ze (8 g/ kg) significantly improved drought tolerance of wheat plants. SA and Ze (8 g/ kg) also had positive effects on control plants. We therefore concluded that external application of SA (1 mM) and Ze (8 g/ kg) is recommended for improving drought tolerance. [ABSTRACT FROM AUTHOR]

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Daytime and nighttime fine aerosol (PM 2.5) samples were collected during a heavy pollution episode in November 2020, January 2021, and also during clean event (August 2020) in New Delhi. These samples (n = 20) were analyzed for water-soluble dicarboxylic acids (diacids) and related compounds, carbonaceous components, and inorganic ions to identify their sources and atmospheric processing in different episodes/seasons. Among the measured organics, oxalic acid (C 2) was found to be the most abundant species followed by terephthalic (tPh), succinic (C 4), phthalic (Ph), and azelaic (C 9) acids. Such high abundance of tPh were different from those in other Asian cities where C 3 is generally the second or third dominant species. tPh very well correlated with OC, Cl− and K+, indicating combustion of biomass and plastic-containing waste may be the possible sources. Significant high contents of diacids, oxoacids, and dicarbonyls were observed during heavy pollution episode, implying an enhanced emission and/or atmospheric processing of these species. Additionally, two important secondary formation pathways for C 2 diacid were discussed in New Delhi, i.e. (i) biomass burning derived (biogenic) volatile organic precursors lead to formation of C 2 diacid through transformation of oxoacids and dicarbonyls by oxidation, and (ii) oxidative degradation of the unsaturated fatty acids results in formation of C 5 and C 4 which subsequently decompose to C 2 diacid. This study demonstrated that both primary emissions in clean event and secondary production during polluted event are important sources of aerosols in New Delhi. [Display omitted] • Second high abundance of tPh reported for the first time in Delhi urban aerosols. • Biomass/plastic-waste burning important sources of aerosols. • Aged aerosols via long-range transport in post-monsoon, while local sources and subsequent processing in winter are dominant. [ABSTRACT FROM AUTHOR]

In this study, the concentration of inorganic ions (SO 4 2−, NH 4 +, NO 3 − and NO 2 −) and morphological characteristics of condensable particulate matter (CPM) were investigated to elucidate the formation mechanism of inorganic CPM from ultra-low emission coal-fired power plants. The concentration of inorganic ions increased with the increase of H 2 O content and concentration of inorganic gaseous contaminants (SO 2 , NO X and NH 3), and decrease of condensation temperature, indicating the enhancement of heterogenous reaction in the saturated flue gas. Furthermore, NO X and SO 2 could undergo redox reactions, leading to an elevation in the concentration of SO 4 2− and NO 3 −. Additionally, the introduction of NH 3 resulted in increased concentrations of SO 4 2−, NO 3 −, and NO 2 −, highlighting the significant role of NH 3 neutralization in CPM nucleation. The condensation of SO 3 /sulfuric acid aerosols was enhanced under saturation conditions, and SO 2 and SO 3 /sulfuric acid aerosols could contribute synergistically to the formation of SO 4 2−. Moreover, morphological analysis revealed the presence of both well-aggregated solid CPM and dispersed liquid CPM, confirming the formation of inorganic CPM during fast condensation. Furthermore, the detected CPM were composed of S and O, which identified the significant role of sulfates in the inorganic CPM. These findings provide valuable insights for the control of inorganic CPM in flue gas systems. [Display omitted] • Condensation temperature and humidity exhibited a significant impact on the formation of inorganic CPM. • The evolution of SO 4 2−, NO 3 −, NO 2 −, and NH 4 + in a complex multi-complex flue gas environment was studied. • Morphological analysis substantiated the particles condensation and agglomeration during rapid condensation. [ABSTRACT FROM AUTHOR]

The measurement of precipitation chemistry enables the assessment of the temporal and spatial evolution of the chemical composition of the atmosphere associated with atmospheric physical and chemical mechanisms. The aims of this study were to report the chemical composition of rainwater collected at a marine environment, i.e. the Cape Point Global Atmosphere Watch (CPT GAW) station from 2004 to 2012. As expected, the volume weighted mean (VWM) concentrations of Na+ (298.64 μEq.L-1) and Cl- (354.18 μEq.L-1) were significantly higher compared to the VWM concentrations of other ionic species, as well as compared to the VWM concentrations thereof at the sites in the South African interior. The average pH of rainwater was slightly lower than the pH of unpolluted rainwater, mainly due to NO3- associated with the occasional influence of the Cape Town metropole. In contrast to the sites situated in the north-eastern South African interior, where anthropogenic SO42- was the major constituent in rainwater, SO42- at CPT GAW was entirely associated with marine air with no anthropogenic contribution. It was also indicated that 94% of the chemical content at CPT GAW can be attributed to the marine source.

The article examines the sorption capabilities of sorbents for water-soluble petroleum products, as well as the mechanism of adsorption in the practical use of sorbents in water purification processes. The process of adsorption of petroleum products and some ions with inorganic sorbents is considered. The study revealed: 1 gram of sorbent absorbs 15-18 grams of oil, which contributes to the effective fight against oil spills in the aquatic environment. It is recommended to use rice husk as an effective sorbent.

• A TiO 2 -based material doped with Fe was effectively supported on polystyrene pellets. • The catalyst proved to be reusable without a loss in photocatalytic performance. • The pH strongly affects adsorption and contaminant photocatalytic degradation. • The nitrate and iron ions produced a boosting effect on photocatalytic performance. • The continuous flow system worked for 8 days with 35 % removal (43 % adding NO 3 –). Experimental tests in batch and continuous modes studied the impact of pH and the presence of inorganic ions on the photocatalytic properties of a visible light-activated titanium oxide catalyst doped with iron. Significantly enhanced photocatalysis was observed in the presence of nitrate and iron ions, while chloride hindered adsorption using Rhodamine B. A strong correlation between pH and photocatalytic performance was noted, along with a connection between the adsorption of the target molecule on the catalyst and subsequent photocatalytic degradation. Supporting the catalyst with polystyrene pellets reduced photocatalytic performance. However, catalyst reuse for four cycles and optimal dosages were achieved. In a continuous system, consistent chemical efficiency was maintained. Over 8 days, removal rates remained around 35 % and 43 % in presence of NO 3 –. Mechanically, no catalyst loss from the support was observed. These findings set the stage for potential industrial-scale applications. [ABSTRACT FROM AUTHOR]

In the present paper, the influence of iodate (IO3−) ions on the photocatalytic process using titanium dioxide (UV/TiO2) was systematically examined. The innovative studied system (UV/TiO2/IO3−) demonstrated high performance in the elimination of safranin O (SO), a model dye, from water due to the implication of iodine radicals (IO3•, IO2•, IO•, etc.). The degradation was assessed by monitoring the change in initial substrate concentration (5–30 mg∙L−1), TiO2 loading (0.01–3 g∙L−1), IO3− concentration, liquid temperature, and initial pH. Further enhancement of oxyanion amount was beneficial for the initial rate of degradation (r0) over the range 0.1–50 mM, such that r0 rose from 0.724 to 1.12 mg∙L−1∙min−1. However, a concentration of 100 mM IO3− slowed the removal kinetics. Low pH values were found to be favorable for pollutant removal. Furthermore, a variety of inorganic and organic substances was employed to clarify the effect of the UV/TiO2/IO3− process in natural waters. The findings revealed a negative impact of chloride excess in seawater and a decline in SO degradation in mineral water as a result of HCO3− presence at more than 1 mM. At high concentrations of natural organic matter, the heterogeneity and the strong adsorption of humic acid on the TiO2 surface were found to be harmful for SO decay.

In this study, the water-soluble inorganic ions (WSIIs) composition of fine particulate matter (PM2.5) was measured in the northern Nanjing city from 2015 to 2021. NH4+, NO3− and SO42− concentrations dominated in total WSIIs (Na+, NH4+, K+, Mg2+, Ca2+, Cl−, NO3− and SO42−), accounting for 87.8%. The nitrate with highest average concentration among all ions was 11.0 μg·m−3. Total WSIIs concentrations were higher in winter and lower in summer, with the highest levels in December (45.6 μg·m−3) and the lowest levels in August (15.1 μg·m−3). NO3−/SO42− was higher than 1, indicating the important contribution of mobile sources. The aerosols exhibited a weak acidic by the molar ratio of water-soluble anions and cations. Positive matrix factorization (PMF) analysis results showed that secondary nitrate and sulfate were the major pollution sources in December 2016 and 2020. The contribution of secondary nitrate in 2020 increased by 47.6% compared to 2016, while that of secondary sulfate decreased by 42.4%. The potential source contribution results demonstrated that for secondary aerosol concentrations, the contribution of regional transport from north of Anhui increased, while the contribution of local emissions decreased. The results from this study could contribute to the better prevention and control of regional air pollution in the future.

Both horseradish peroxidase (HRP) and ferrous ion (Fe2+) can degrade organic micropollutants (e.g., sulfamethazine) in the presence of hydrogen peroxide (H2O2), but they have their own disadvantages, such as low degradation efficiency and low pH condition, respectively. In order to overcome the above shortcomings, this study is to develop a HRP-Fenton-like system for sulfamethazine (SMR) efficient degradation by analyzing the optimal reaction conditions, degradation mechanisms, and effect of ions. Results show that HRP and Fe2+ achieve effective coupling by adding trace Fe2+ (≤ 10 μmol/mL) to the HRP system at pH = 5, and the degradation rate of SMR increased by 20.7–42% depending on Fe2+ concentration compared with single HRP treatment. Consumption of H2O2 and quenching of hydroxyl radicals confirmed that HRP dominated SMR removal in the HRP-Fenton-like system. HPLC-MS analysis shows that SMR was degraded by C-S bond breaking, N-S bond breaking, hydroxyl substitution, and rearrangement. Furthermore, Cl−, HCO3−, and NO3− exhibit an acceptable negative effect, while SO42− shows a positive effect on the degradation of SMR. [ABSTRACT FROM AUTHOR]

Naturally and anthropogenically emitted aerosols, which are determined by their physical and chemical properties, have an impact on both air quality and the radiative properties of the earth. An important source of atmospheric particulate matter (PM) in South Africa is household combustion for space heating and cooking, which predominantly occurs in low-income urban settlements. The aim of this study was to conduct a detailed size-resolved assessment of chemical characteristics of aerosols associated with household combustion through the collection of particulates in low-income urban settlements in South Africa in order to quantify the extent of the impacts of atmospheric pollution within these settlements. Outdoor (ambient) and indoor aerosols in different size fractions were collected during summer and winter in four low-income urban settlements located in the north-eastern interior on the South African Highveld. The mass concentration and chemical composition was determined for three size fractions, namely, PM1, PM25 and PM25-10. The highest concentrations of particulates were measured indoors with the highest mass concentration determined in the indoor PM2.5-10 (coarse) size fraction. However, the highest mass concentrations were determined in PM1 in all outdoor aerosol samples collected during winter and summer, as well as in indoor samples collected during summer. Significantly higher concentrations were determined for SO4-2 in outdoor and indoor particulates compared to other ionic species, with NH4+ and NO3- being the second most abundant. SO4-2 and NH4+ almost exclusively occurred in the PM1 size fraction, while NO3- was the major constituent in the larger size fractions. The highest SO4"2 levels were recorded for the winter and summer outdoor campaigns conducted at Zamdela, while NO3- and NH4+ concentrations were higher during the winter outdoor campaign. The combined concentrations of trace elements were higher for indoor particulates compared to outdoor aerosols, while the total trace element concentrations in PMi were substantially higher than levels thereof in the two larger size fractions of particulates collected during all sampling campaigns. No distinct seasonal trend was observed for the concentrations of trace elements. Na, Ca and Cr had the highest concentrations in particulates collected during outdoor and indoor sampling campaigns. Ni concentrations in outdoor and indoor aerosols exceeded the annual average European standard PMi collected during all sampling campaigns in low-income urban settlements had the highest organic- and elemental carbon (OC and EC) concentrations. The highest OC and EC levels were determined in PMi collected during the winter indoor campaign. OC and EC concentrations were highest during winter, which can be attributed to changes in meteorological patterns and increased household combustion during winter. Low OC/EC ratios determined for particulates collected in low-income urban settlements are indicative of OC and EC being mainly associated with local sources of these species. OC concentrations determined in this study were an order of magnitude lower than OC concentrations determined for ambient aerosols collected in the north-eastern interior of South Africa, while similar EC levels were measured. According to estimated dust concentrations, it was indicated that dust is the major constituent in all size ranges of particulates collected in this study, while trace elements were the second most abundant. However, trace elements made the highest contribution to indoor PM1 and PM1-2.5 mass. Mass concentrations and chemical concentrations determined for aerosols collected in low-income settlements reflects the regional impacts of anthropogenic sources in the north-eastern interior of South Africa, as well as the influence of local sources. [ABSTRACT FROM AUTHOR]

Gaseous pollutants serve as precursors of ionic particles in the atmospheric environment, thus their control is necessitated along with the particulate with special reference to soluble ions. The present study was undertaken to assess the effect of Particulate Matter (PM10) associated Water-Soluble Ions (WSI) on the ambient air concentration. In total 134 airborne particulate matter (PM10) samples were collected from 11 stations from January to December in and around Gandhidham, Gujarat, India. Monthly sampling was carried out by the Respirable Dust Sampler (RDS) on 24 hr basis. The samples were subjected to chemical analyses for estimating water-soluble ions. The PM10 concentration in the analyzed samples ranged from 29 to 401 µg/m3. The amount of Na+, Ca2+ and K+ varied from 0.04 to 8.43 µg/m3, Below Detection Level (BDL) to 12.25 µg/m3, and 0.09 to 3.49 µg/m3, respectively following flame photometer method. The anions SO 2-, NO - and Cl- ranged from 0.31 to 3.68 µg/m3, 0.39 to 32.47 µg/m3, and 4.03 to 54.08 µg/m3, respectively. Higher concentrations were reported for all the ions during winter. From the results, it is evident that secondary anthropogenic aerosols, natural mineral aerosols and mixed sea salt contributed to higher ionic concentrations in the air. [ABSTRACT FROM AUTHOR]

Abstract Background Chenopodium quinoa Willd., a halophytic crop, shows great variability among different genotypes in response to salt. To investigate the salinity tolerance mechanisms, five contrasting quinoa cultivars belonging to highland ecotype were compared for their seed germination (under 0, 100 and 400 mM NaCl) and seedling’s responses under five salinity levels (0, 100, 200, 300 and 400 mM NaCl). Results Substantial variations were found in plant size (biomass) and overall salinity tolerance (plant biomass in salt treatment as % of control) among the different quinoa cultivars. Plant salinity tolerance was negatively associated with plant size, especially at lower salinity levels (

As the major constituents of PM2.5, carbonaceous constituents and inorganic ions have attracted emerging attentions on their health risks, particularly on cardiorespiratory diseases. However, evidences on the risks of PM2.5 constituents on other diseases (eg. nervous disease, genitourinary disease, neoplasms and endocrine disease) remain scarce. In our study, we firstly calculated residuals of PM2.5 constituents regressed on PM2.5 to remove the confounding effect of PM2.5. Then, generalized additive model (GAM) was used to assess impacts of residuals of PM2.5 constituents on mortality from 36 diseases (10 broad categories and 26 subcategories) during 2011–2015 in Guangzhou, China. Results of constituent-residual models showed that only EC, OC and NO3- were significantly associated with all-cause mortality, with per IQR change in corresponding constituent residuals related to percentage changes of 1.69% (95% CI: 0.42, 2.97), 1.94% (95% CI: 0.37, 3.54) and 2.59% (95% CI: 1.02, 4.18) at lag 03 days. All these pollutants were significantly associated with elevated mortality risk of cardiovascular disease, but only EC was significantly associated with respiratory mortality, and NO3- with endocrine disease and neoplasm. For more specific causes, the highest effect estimates of EC and NO3-were both observed on mortality from other form of heart disease, and OC on intentional self-harm, with estimates of 11.45% (95% CI: 2.74, 20.91), 12.59% (95% CI: 1.41, 25.02) and 18.01% (95% CI: 2.14, 36.36), respectively. Our findings highlighted that stricter emission control measures are still warranted to reduce air pollution level and protect the public health.

Cornus florida and Cornus hongkongensis subsp. elegans are potential species in saline-alkali areas for use as horticultural plants with high ornamental value. This work aimed to screen suitable tolerant dogwoods by comparing the responses of two dogwoods to salt stress according to phenotypic and physiochemical indicators on germination and seedling growth. For relieving seed dormancy, two pretreatments were performed on seeds, coded as T1 (soaked by gibberellic acid (GA3) alone) and T2 (soaked by GA3 with gradient salt concentrations of 0.2%, 0.3%, 0.4%, and 0.45%), and pretreated seeds were then germinated at the corresponding salt concentrations in pretreatment. As salt levels increased, the seed germination parameters decreased for both dogwoods, whereas the relative salt damage rate (SDR) significantly increased. While the growth of above-ground parts was significantly inhibited, that of underground parts changed little. Furthermore, the malondialdehyde content (MDA), superoxide dismutase activity (SOD), organic solutes (soluble sugar (SS) and proline (Pro)), and inorganic ions (K+, Na+, Ca2+) significantly accumulated in seedlings with increasing salinity levels, whereas K+/Na+ ratio decreased. Correlation analysis indicates that organic osmolyte (SS) and ion osmoregulation could be the main physiological mechanisms conferring salinity tolerance for both dogwoods. Compared with osmolytes, ion osmoregulation may be more critical for salt tolerance in the seedlings of the studied dogwoods. Collectively, the superior salt tolerance of C. florida to C. hongkongensis subsp. elegans suggests that the two species could be cultivated in saline areas with 0.3% and 0.2% salt levels, respectively.