Total Concentrations Of Zn Research Articles

Potentially toxic element accumulation in two Equisetum species spontaneously grown in the flotation tailings

Decades of mining activity have resulted in the accumulation of significant amounts of tailings that are deposited over the natural vegetation, forming deposits tens of meters thick. The tailings are poor in organic matter and macronutrients and contain a high concentration of potentially toxic elements (PTE). Their surface remains unvegetated for long periods of time and is susceptible to fluvial and wind erosion. Equisetum arvense and E. telmateia appear to be the first colonizers in the tailings of the Pb?Cu?Zn mine in Serbia. Each plant was sampled along with its associated substrate. Pseudototal and available metals in the substrate, as well as total As, Cd, Cu, Fe, Mn, Ni, Pb and Zn concentrations in the plant parts were determined by atomic absorption spectrophotometry. The findings show that both species have high bioaccumulation capacity and tolerance to otherwise toxic concentrations due to efficient accumulation, immobilization and detoxification of these elements in their underground parts. It is expected that the long-term presence of metal-tolerant horsetail species would increase the organic matter content of flotation residues, thus gradually improving their physical, chemical and biological properties. This, in turn, would promote the natural succession of other metaltolerant plant species and soil microorganisms.

Effects of sulfate on the photosynthetic physiology characteristics of Hydrocotyle vulgaris under zinc stress.

The effects of sulfate on the zinc (Zn) bioaccumulation characteristics and photophysiological mechanisms of the ornamental plant Hydrocotyle vulgaris were explored using a hydroponic culture under three Zn concentrations (300, 500 and 700mgL-1 ) with (400μmolL-1 ) or without the addition of sulfate. Results showed that: (1) tissue Zn concentrations and total Zn contents increased with increasing hydroponic culture Zn concentrations; and sulfate addition decreased Zn uptake and translocation from roots to shoots; (2) Zn exposure decreased photosynthetic pigment synthesis, while sulfate changed this phenomenon, especially for chlorophyll a under 300mgL-1 Zn treatment; (3) Zn exposure decreased photosynthetic function, while sulfate had positive effects, especially on the photosynthetic rate (Pn ) and stomatal conductance (Gs ); and (4) chlorophyll fluorescence parameters related to light energy capture, transfer and assimilation were generally downregulated under Zn stress, while sulfate had a positive effect on these processes. Furthermore, compared to photosynthetic pigment synthesis and photosynthesis, chlorophyll fluorescence was more responsive, especially under 300mgL-1 Zn treatment with sulfate addition. In general, Zn stress affected photophysiological processes at different levels, while sulfate decreased Zn uptake, translocation, and bioaccumulation and showed a positive function in alleviating Zn stress, ultimately resulting in plant growth promotion. All of these results provide a theoretical reference for combining H. vulgaris with sulfate application in the bioremediation of Zn-contaminated environments at the photophysiological level.

Dynamics of Zinc Fractions in Soil as Affected by Zinc Fertilization in a Maize-maize Cropping Sequence in Upper Brahmaputra Valley Zone of Assam, India

Zinc is considered as an important micronutrient for maize which is a promising emerging cash crop for the state of Assam, India. A field experiment was conducted at the experimental farm of Krishi Vigyan Kendra, Jorhat, Assam Agricultural University during 2018-19 and 2019-20 to study the dynamics of zinc fractions in soil in a maize-maize cropping sequence as affected by zinc fertilization. The experiment was laid down in a randomized block design (RBD) with twelve treatments combinations of basal and foliar application of zinc through zinc sulphate and zinc oxide nanoparticles (ZnO NPs). The results revealed that zinc fertilization significantlyinfluenced the studied zinc fractions in soil during both the years under investigation. The distribution of different zinc fractions in soils at harvest was found in the following order: water soluble plus exchangeable-Zn < complexed-Zn < crystalline sesquioxide bound-Zn < amorphous sesquioxide bound-Zn < residual-Zn. Among the zinc treatment combinations, soil application of Zn @ 3.75 kg ha-1 in combination with foliar application of 500 ppm ZnO NPs exhibited the highest concentration of water soluble plus exchangeable-Zn content (1.10 ppm) in soil. The highest concentration of complexed-Zn (2.95 ppm), amorphous sesquioxide-bound-Zn (4.11 mg kg-1), crystalline sesquioxide-bound-Zn (3.76 ppm), residual-Zn (125.65 ppm) and total-Zn (137.33 ppm) were recorded in the treatment receiving soil application of Zn @ 7.5 kg ha-1. Among the zinc fractions studied, the concentration and percent contribution of water soluble plus exchangeable-Zn to total-Zn was the lowest while residual-Zn fraction contributed the highest to the total soil zinc pool. Furthermore, path coefficient analysis revealed that the water soluble plus exchangeable-Zn had the highest contribution towards the plant available DTPA extractable-Zn in soil. Moreover, all the fractions of zinc were found to be significantly and positively correlated with each other indicating existence of dynamic equilibrium of zinc in soil.

Nanoporous zeolite and its effect on the immobilization of trace elements in soils from scrap landfills under aided phytostabilization

AbstractThe rising prerequisite for developing novel green remediation methods for trace‐element‐contaminated lands is allied to the necessity to really mend the soil environs. The effectiveness of zeolite‐aided phytostabilization (AP) of soil contaminated with trace elements (TEs), from a scrap yard, using Lolium perenne as the plant for testing, was determined and discussed. The variability and activity of the rhizospheric bacterial community were also examined. The initial soil used in the AP experiment was characterized by especially high total contents of Zn, Pb, Cu and Cd. The TE total contents in roots and aboveground parts of L. perenne as well as in the phytostabilized soil materials were analyzed with flame atomic absorption spectrometry. The study revealed that the addition of natural zeolite into TE‐contaminated soil increased the relative plant biomass as well as the soil pH value as compared to the phytostabilized non‐amended series, whereas the total contents (with respect to an absolute value) of Zn, Pb, Cu and Cd were generally higher in roots than in the aboveground parts of L. perenne. In particular, the incorporation of zeolite to the soil contributed most significantly to the considerable relative decrease in the total contents of Cu, Pb, Cd and Zn in the soil, as well as the content of bioavailable and leachable speciations of Cd, Cu, Zn and Pb extracted from the soil using CaCl2 solution as compared to the non‐amended series. In the phytostabilized zeolite‐amended soil, the overall bacterial diversity decreased but the presence of zeolite favoured the growth of microorganisms belonging to Gammaproteobacteria, Planctomycetia, and Thermomicrobia, in particular, the genera Mycobacterium, Williamsia, and Prochlorococcus.

Assessment Toxicity of Soils from Areas with Mining Activity Through the Stability of the Lysosomal Membrane and Avoidance Behavior in the Earthworm Eisenia fetida.

The aim of this study was to determine the effect of soils from areas with mining activity on the stability of the lysosomal membrane and avoidance behavior in the worm Eisenia fetida. Texture, organic material, conductivity and pH were determined in soils. The total concentrations of Cu, Zn, Pb, Ni, As and Hg were determined in tissues of E. fetida and in soils. Neutral red retention time (NRRT) was determined in hemocytes, and behavior with the avoidance test, in the earthworm. Cu (1563 ± 58mg kg-1) and Zn (135 ± 9mg kg-1) had the highest mean concentrations in the soils, while Hg (0.01 ± 0.001mg kg-1) had the lowest concentration in all the soils. The soil with the highest Cu concentration produced an avoidance of > 80%. Most of the soils produced a significant loss of the stability of the lysosomal membrane. The variables organic material and sand would facilitate habitat selection in E. fetida, In conclusion, the soils have chemical agents in bioavailable concentrations that provoke adverse cellular effects and evasion behavior. We propose the use of both response variables as early alerts in the evaluation of soils.

Heavy metals in coastal soils and sediments of the ponds in Samara

The total contents of Mn, Cr, Ni, Cu, Zn, Pb and Cd in foreshore soils and bottom sediments of 20 ponds have been investigated for the first time in Samara by the method of spectrometry with inductively coupled plasma. It is shown that polymetallic pollution of coastal soils and bottom sediments of 16 ponds out of 20 considered is acceptable; 3 ponds, located in the 13th microdistrict (small pond) and on the Solnechnaya street (large and small ponds), are characterized by moderately hazardous pollution with heavy metals; 1 pond, located in the area of the former Hippodrome, has a high level of pollution of coastal soils. Cu, Zn and Pb should be considered to be the main elements that significantly affected the ecological state of coastal soils and bottom sediments of the studied ponds. Their content in selected samples ranged: from 0,3 to 20,3 for Cu, from 0,2 to 14,9 units for Zn, from 0,2 to 25,2 units of background concentrations to Pb. The analysis of heavy metals average levels in coastal soils and bottom sediments of Samara ponds showed, that bottom sediments were enriched with all analyzed metals except Mn in comparison with coastal soils, whereas Mn was accumulated to upper levels in coastal soils. The location of water bodies in various parts of the urban area relief caused differences between the levels of heavy metals accumulation. For instance, the coastal soils of the ponds located on the watershed between the Saratov reservoir and the Samara River accumulated heavy metals more actively than the coastal soils of the ponds on the Volga slope. The accumulation of heavy metals in bottom sediments on the watershed was more active for Mn, Cr, Zn and Cd whereas in the ponds on the Volga slope it was shown for Ni, Cu and Pb.

Bioaccessibility and health risk assessment of trace metals in Nanjing park dust

The bioaccessibility, chemical fractions, and total concentrations of Hg, As, Mn, Ni, Cd, Cr, Cu, Pb and Zn were determined in 17 urban park dust samples collected from a megacity in China. The geoaccumulation index indicated heavy Hg pollution, moderate Cd pollution, and slight to moderate Cu, Pb and Zn pollution. The inhalation bioaccessibility measured by the Artificial Lysosomal Fluid method decreased in the order of Cd > Zn > Mn > Ni > Pb > As > Cr > Cu. The ingestion bioaccessibility measured by the Physiologically Based Extraction Test decreased in the order of Cd > Zn > Mn > Cu > Pb > As > Ni > Cr. The modified European Community Bureau of Reference method was used to extract the chemical fractions of trace metals. As (87%), Cr (87%), and Hg (99%) were predominantly found in residual fraction (F4), whereas Cd was predominantly found in water soluble and exchangeable fraction (F1 34%) and carbonate, oxidizable and reducible fraction (F2 27%). The first two chemical fractions of the trace metals were closely correlated with their bioaccessibilities. The carcinogenic and non-carcinogenic risks of exposure to trace metals in park dust were assessed using inhalation bioaccessibility and ingestion bioaccessibility. The hazard indexes of all investigated trace metals were below the safe level of 1. The carcinogenic risks of As, Ni, Cd and Cr were also below the acceptable level (10−6), indicating that there was no non-carcinogenic or carcinogenic risk from trace metals in the park dust.

Impact of Foliar Application of ZnO and Fe3O4 Nanoparticles on Seed Yield and Physio-Biochemical Parameters of Cucumber (Cucumis sativus L.) Seed under Open Field and Protected Environment vis a vis during Seed Germination.

Nutritionally rich cucumber seeds remain in demand in the agricultural, health and cosmetic sectors as they are essential for a successful crop stand establishment and seed-based products. However, the production of cucumber seeds is impeded by source limitation and nutrient deficiency. The foliar application of micronutrients can supplement this deficiency and overcome the physiological setback. An experiment was undertaken to compare the impacts of the foliar application of Fe and Zn, as nanoparticles and fertilizers, on the yield and seed quality of cucumber under open and protected environments. A foliar spray of nano-ZnO (ZnNPs) and nano-Fe3O4 (FeNPs) at 100, 200 and 300 mg L-1, as well as ZnSO4 and FeSO4 as fertilizer (0.5%), was conducted at the vegetative stage and pre- and post-flowering stages. The NPs had a greater efficacy in an open field than in the protected (naturally ventilated poly house) environment. The application of both NPs increased seed yield (51.7-52.2%), total chlorophyll content (15.9-17.3%) and concentration of Zn and Fe in the fruit and the seed, by 2.0-58.5% and 5.0-30.5%, respectively. A significant increase in starch, soluble proteins, soluble sugars and oil content was observed in the seeds from the NP treated plants. NP treatment also enhanced the germination-related parameters, such as percent germination (16.8-17.0%), rate of germination (18.0-22.2%) and seedling vigor (59.8-72.6%). The biochemical characterization showed a significant improvement in the seed water uptake and the activity of hydrolytic enzymes (amylase and protease) in the germinating seed. The involvement of reactive oxygen species (superoxide anion and hydrogen peroxide) and antioxidant enzymes (Superoxide dismutase, Catalase and Peroxidase) in the germination process was indicated by an increase in their activities in the seeds from NP treated plants. Hence, the study proposes the potential benefit of the foliar application of 300 mg L-1 ZnNPs and 200 mg L-1 FeNPs at crucial stages of plant growth to improve the yield and seed quality in cucumbers.

Human and ecological risk assessment, geo-accumulation, and source apportionment of road dust heavy metals in a semi-arid region of central Iran

ABSTRACT This investigation aims to identify sources and assess the concentrations, spatial distribution patterns, and ecological and health risks of Zn, Pb, Cu, Ni, Cr, and Cd from road dust (RD) samples collected from Qom, Iran. Samples were collected from the surface of the roads, and were air-dried for 15 days. Debris including hair and leaves were removed from samples by using 1000-μm nylon sieve. One gram of each dried samples were digested according to US environmental protection agency (USEPA) method using HCl, HNO3, and H2O2 for analysis of heavy metals (HMs), and utilising inductively coupled plasma optical emission spectrometry (ICP-OES). The mean concentrations for all HMs have higher values in the warm season with total mean concentrations of Zn = 227.3 > Pb = 130.1 > Ni = 94.2 > Cu = 78.7 > Cr = 39.5 > Cd = 2 mg/kg. Furthermore, correlations between all concentrations have been investigated using Pearson’s method after approving normal distribution for all HMs through Kolmogorov-Smirnov (K-S) test. The spatial distribution of Pb, Zn, and Ni show higher concentrations in the periphery of Qom, while Cu, Cr, and Cd are almost the same for the whole city. The geo-accumulation index (I geo ) categorised all HMs as uncontaminated (average I geo <0) except for Pb and Zn with average I geo of 1.52 and 1.01, respectively. Ecological risk (E r ) analysis confirms lower risk for all HMs (average E r <40). The warm season exhibits a higher potential ecological risk index (average RI = 81.73) for all components compared to the cold season (average RI = 75.85). Hazard index (HI), and carcinogenic risk assessment (CRA) values ranged lower than 1 and 10−6, respectively, and thus, revealed negligible health risks for individuals. Positive matrix factorisation (PMF) points to four factors for HMs dominantly affected by traffic-related and anthropogenic activities (contributing 38.56%), and natural sources (accounting for 32.45%) in the cold and warm seasons, respectively.

Distribution of Trace Metals in Ice and Water of Liaodong Bay, China.

Trace metal pollution in coastal seas has been of great concern because of its persistence, toxicity, and biological accumulation through the food chain. The role of sea ice in trace metal transport and distribution in Liaodong Bay is still unknown. Sea ice and water samples were collected in Liaodong Bay in February 2021 to assess the distributions of Cu, Pb, Cd, Zn, Cr and Hg during the frozen season. Total dissolved (&lt;0.45 μm) and particulate (&gt;0.45 μm) heavy metal concentrations were measured by atomic absorption spectrophotometry (Cu, Pb, Cd, Zn and Cr) and atomic fluorescence spectrophotometer (Hg). The ice held significantly higher levels of total Cr when compared to water. There were no significant differences in total concentrations of Cu, Pb, Cd, Zn and Hg between water and ice samples. An analysis of dissolved-to-total metal ratios shows that all studied metals in the dissolved phase, except Hg, are found exclusively in Liaodong Bay nearshore ice as a result of desalination. Concentrations of particulate metals are higher in sea ice than in seawater due to suspended/bed sediment entrainment and atmospheric deposition. The partitioning coefficients of six trace metals are not increased with the increase in the concentration of particulate matter in sea ice due to sediment accumulation. The redistribution of trace metals between seawater and ice was a result of comprehensive effects of physico-chemical processes and environmental factors, such as chemical oxygen demand, salinity, and suspended particulate material.

Influence of Different Rates and Frequencies of Zn Application to Maize–Wheat Cropping on Crop Productivity and Zn Use Efficiency

Nowadays, zinc (Zn) fertilizers are commonly used for quality food production globally. Knowledge about proper application time and rates of commercial Zn fertilizers is necessary to obtain higher crop production and improve Zn use efficiency. A long-term field experiment was conducted during 2012 to 2018 at Anand Agricultural University, Anand (Gujarat), India, to find out the right Zn fertilizer dose and its frequency of application in maize–wheat cropping systems grown on typic haplustepts soil. The study comprised of three frequency levels, i.e., Zn application in the first year only (F1), alternate year (F2), and every year (F3), with four different rates of Zn, i.e., 2.5, 5.0, 7.5, and 10.0 kg Zn ha−1 per year imposed in the maize–wheat cropping system in each kharif season (during June to September) for six years. Findings of the study revealed that Zn applications to maize at 7.5 and 10 kg ha−1 in alternate year and 5.0 to 10 kg ha−1 in every year significantly increased maize equivalent yield as compared to no-Zn treatment. Application of 10.0 kg Zn ha−1 per year produced higher grain size, straw, and total Zn concentrations compared to those observed under no-Zn application in maize and wheat crops. Diethylene triamine penta acetic acid extractable Zn concentration in soil was higher in Zn treated plots which received Zn application at 5.0, 7.5, and 10.0 kg ha−1 in alternate years and 10 kg ha−1 in every year as compared to no-Zn application. Apparent Zn recovery efficiency varied from 0.17 to 1.46% for maize crop and 0.34 to 1.70% for wheat crop under different rates and frequencies of Zn application. The above results emphasize the importance of Zn retention capacity of soil regarding its response to different rates and frequencies of Zn application to maize and wheat crops.

Effects of 12-Year Nitrogen Addition and Mowing on Plant-Soil Micronutrients in a Typical Steppe.

Changes in soil micronutrient availability may have adverse consequences on grassland productivity, yet it’s still largely unclear how concurrent human practices, such as fertilization and mowing, affect micronutrient cycling in the plant-soil systems. Here, we measured six essential micronutrient (Fe, Mn, Cu, Zn, Co and Mo) contents in both plant pool (separated as aboveground plant parts, litter, and belowground roots) at the community level and soil pool (0−10 cm depth) after 12-year consecutive nitrogen (N) addition (0, 2, 10, and 50 g N m−2 year−1) and mowing in a typical steppe of the Mongolian Plateau. The results show that (i) medium-N (10 g m−2 year−1) and high-N (50 g m−2 year−1) addition rates significantly increased contents of soil-available Fe (+310.0%, averaging across the two N addition rates), Mn (+149.2%), Co (+123.6%) and Mo (+73.9%) irrespective of mowing treatment, whereas these addition treatments usually decreased contents of soil total Fe (−8.9%), Mn (−21.6%), Cu (−15.9%), Zn (−19.5%), Co (−16.4%) and Mo (−34.7%). (ii) Contents of Fe in aboveground plant parts, litter, and roots significantly decreased, whereas plant Mn increased with N addition. Contents of above ground plant Cu, Zn, Co, and Mo significantly decreased at high-N addition rate, whereas contents of micronutrients in roots and litters, except for Fe, generally increased with N addition. Moreover, the total amount of micronutrients in the plant pool (contents × biomass) significantly increased at the medium-N addition rate but decreased at the high-N addition rate. All N addition rates significantly enlarged the pool of litter micronutrients, and roots could hold more micronutrients under N addition, especially combined with mowing treatment. Importantly, although mowing could regulate the effects of N addition on variables (i) and (ii), the effects were weaker overall than those of N addition. (iii) Changes in root micronutrients, except for Mn, could explain corresponding changes in plant micronutrients (R2: 0.19−0.56, all p < 0.01), and significant linear correlations were also observed between soil-available Fe and Fe in plant and roots. Aboveground plant Mn was significantly correlated with soil-available Mn, while Co and Mo in roots were also significantly correlated with soil-available Co and Mo. These results indicate that soil micronutrient supply capacity may decrease due to a decrease in total micronutrient contents after long-term N addition and mowing. They also suggest that different magnitude responses of soil micronutrients in plants (i.e., litters, roots) and soil should be considered when comprehensively examining nutrient cycling in grassland ecosystems.

Migration characteristics and ecological risk assessment of heavy metals in ash from sewage sludge co-combustion in coal-fired power plants

Co-combustion in coal-fired power plants is one of the main methods to dispose of municipal sewage sludge (MSS). The high heavy metals content of MSS increases the ecological risk of ash from the coal and MSS co-combustion. In response to this problem, the three types of fly ash or bottom ash from MSS co-combustion in the three coal-fired power plants were sampled. The properties of fly ash and bottom ash were analyzed in terms of ash composition, particle size distribution, heavy metals content and leaching characteristics. The potential ecological risks were evaluated using the ecological risk index assessment method. The results showed that the co-combustion of MSS had no significant effect on the ash composition order and heavy metals content order. However, the total content of Cu, Mn, Pb and Zn, Hg in the co-combustion ash was higher than that in the coal-fired ash without sludge blending but did not exceed the risk screening value for soil heavy metal contamination of residential land. Heavy metals showed significant enrichment in fly ash and dilution in bottom ash. The leaching concentrations of Cr and Ni were several times the limit value. The potential ecological risk levels of fly ash and bottom ash were moderate risk and high risk respectively. Cr and Hg were the main contributors to potential ecological risks. The contents of Cr, Hg and Ni need to be paid attention to in the subsequent utilization of coal ash mixed with co-combustion of sewage sludge.

Remediation of Cd and Zn contaminated soil by zero valent iron (Fe0): A field trial

Remediation of contaminated soil is a long-term challenge faced by human beings. The in-situ remediation was carried out using zero valent iron (Fe 0 ) with the rotation pattern of soybean–rape the near a smelter influenced by atmospheric subsidence. The results showed that the total contents of Cd and Zn in rhizosphere soils with Fe 0 treatment were lower than that in the control. The biomass of soybean and rape increased by 55.4 ∼ 64.9% and 6.2 ∼ 42.8%, respectively with the addition of Fe 0 . And Fe 0 decreased the availability of Cd and Zn and the accumulation of Cd and Zn in plant roots. The Cd and Zn contents of the iron-rich substances separated from soil were much high, reaching 155.8 mg/kg and 29525 mg/kg, respectively and the total Cd and Zn in the remaining soil decreased by 28.5% and 44.6%, respectively. XRD and XPS analysis of the separated substance implied that the new production of iron oxides ( γ -FeOOH and γ -Fe 2 O). The existence of CdO and CdS were observed and the main forms of Zn were ZnS, ZnO and ZnCO 3 through the immobilization of iron oxides. This work suggested the feasibility of Fe 0 in the contaminated soil. Using retrievable materials from soil to remove permanently pollutants should be considered in the future remediation practice. • The in-situ remediation effect of zero valent iron (Fe 0 ) on Cd and Zn was explored. • Fe 0 decreased the contents of Cd and Zn in crop roots. • The iron-rich substance had high contents of Cd and Zn. • The iron-rich substance was retrieved successfully from soil.

Mobile trace elements in sediments from lakes Hawassa, Koka, and Ziway in the Ethiopian Rift Valley.

The present work focuses on total concentrations of trace elements such as chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd), and lead (Pb) and their operationally defined speciation in surface sediments from three Ethiopian Rift Valley Lakes (Hawassa, Koka, and Ziway). Total concentrations were determined using inductively coupled plasma-mass spectrometer (ICP-MS). A six-step sequential extraction was also applied to evaluate the mobilization potential of these elements. Compared with the consensus-based sediment quality guidelines (SQGs) developed for freshwater ecosystems, the total Zn concentration in sediments from Lakes Hawassa and Ziway, as well as Cr, Ni, and Zn in sediments from Lake Koka, was higher than the probable effect concentration (PEC), suggesting that these elements could have a negative effect on benthic organisms. The sequential extraction results showed that Cd, Mn, and Se were to a certain extent associated with the reversible fractions (F1-F3) in sediments, and thereby more mobile than the other investigated trace elements. Predictions of mobility of trace elements using the distribution coefficients (Kd) values were also in agreement with the sequential extraction results. Furthermore, multivariate statistical analyses showed that redox-sensitive fractions (F4 and F6) and the residual fraction (F7) were the dominant factors controlling most trace element mobility. Finally, applying the Risk Assessment Code (RAC) classification system, results showed that Mn in Lake Koka could pose a high risk, while Cd and Mn in Lake Hawassa as well as Cd, Mn, and Se in Lake Ziway sediments could pose medium risk to benthic organisms.

Comparative Study of the Nutritional Composition and Antioxidant Ability of Soups Made from Wild and Farmed Snakehead Fish (Channa Argus)

In recent years, fish soup has become an important product for commercial processing of fish due to its health effects. In this study, nutritional composition and antioxidant ability of soups prepared from farmed and wild snakehead fish were analyzed (hereafter FS and WS soup, respectively). For the FS soup, the proximate composition of protein, fat, ash, free amino acids, and soluble peptides were 2.55%, 0.89%, 0.92%, 0.47%, and 0.62%, respectively. The total amino acid was 390.11 mg/ g, and the proportion of essential amino acid was 27.59%. The total fatty acid was 13.64 g/100 g, of which monounsaturated fatty acid was 5.78 g/100 g, n-6 polyunsaturated fatty acid 3.50 g/100 g, and n-3 polyunsaturated fatty acid 0.41 g/100 g, respectively. The contents of Zn and Ca were 9.04 mg/ kg and 1.13 mg/ g, respectively. The DPPH radical-scavenging ability, Fe2+ chelating ability, and hydroxyl radical-scavenging ability was 57.89%, 21.21%, and 25.61%, respectively. Overall, there was no obvious difference in the nutritional composition and antioxidant activity between the FS and WS soups. The protein content (1.90%) of the WS soup was relatively lower, but the total fatty acid (16.22 g/100 g), MUFA (7.17 g/100 g), and Zn (12.57 mg/ kg) contents were significantly higher.

The Effects of Five-Year Biosolid Application on the Diversity and Community of Soil Arthropods

Land application of biosolids is a beneficial form of management, although heavy metal contamination is a major concern. Biosolid application can shape the abundance, species richness, and community structure of arthropods, which are important regulators of soil processes. We investigated the effect of the five-year (2012–2017) application of domestic biosolids at 0, 15, 30, and 45 ton ha−1 on the soil properties, enzyme activity, heavy metal concentrations, abundance, and diversity of soil arthropods in degraded sandy soil. The results showed that the application of a high amount of biosolids resulted in an increase in soil organic carbon of 2.6 times and in the water content of 2.8 times compared with CK (no biosolids). The total metal concentrations of Cr, Ni, Cu, Zn, Cd, and Pb increased by 6.6%, 3.2%, 6.6%, 7.7%, 13.3%, and 22.5%, respectively, compared with CK in soil (p &gt; 0.05). The activities of seven enzymes, which mainly participate in carbon (C), nitrogen (N), phosphate (P), and sulfur (S) transformation, increased by 1.53%~122.7%, indicating that the soil function did not change under biosolid application. The number of individual arthropods collected from a square meter of soil changed from 0 to 2560. The total abundance of arthropods increased from 1.2 to 4 times under biosolid application (p &lt; 0.05), but biosolid application had no effects on simple measures of richness and diversity (Shannon–Weaver index). Multivariate ordination techniques showed a significant shift of the arthropod community structure under biosolid application due to differing responses of several taxa to the biosolids. Redundancy analysis highlighted the influential role of soil chemical properties (soil organic C, total N, water content, microbial biomass, and pH) and cadmium in shaping the soil arthropod structure. These results suggest that long-term biosolid application with limited heavy metal concentrations does not have detrimental effects on soil arthropods or microbial-related soil function.

Effect of organic acids and soil particle size on heavy metal removal from bulk soil with washing.

To evaluate the effect of soil particle size on heavy metals removal by washing, two soil samples were collected around a lead-zinc mining area (SM) and lead-zinc smelter (SS). The total content of Cd, Pb and Zn in SM and SS were determined. And the effect of soil particle size on Cd removal by low molecular organic acids was studied. The results showed that Cd was the main pollutant and the total content of Cd in SS can reach to 24.8mg Kg-1. 68.4% of the total Cd in SM existed in the form of residual state, while 54.7% of the total Cd in SS was in weak acid extractable state. About 50.0% of the Cd distributed in < 2μm soil size fraction. The washing results indicated that citric acid was a highly efficient eluent among the five low molecular weight organic acids (citric acid, malic acid, tartaric acid, oxalic acid and acetic acid). After washing, 40% and 69.6% of the total Cd in SS and SM can be removed by citric acid, respectively. While only 18.7-40.2% and 32.6-68.7% of Cd was removed from different size fractions of SM and SS, respectively. The species of Cd in soil size fractions affected the removal effect of citric acid. The citric acid can easily remove the weak acid extractable and reducible form of Cd in soil. After eluted by citric acid, the bioavailability of Cd in soil decreased markedly, and the highest decreasing rate reached 93%.

A six-month study of anti-SARS-CoV-2 BNT162b2 mRNA vaccination: A comparative analysis of essential trace elements and anti-RBD IgG sera levels

BackgroundAlthough essential trace elements (ETEs) play pivotal roles in life-supporting biochemical processes, their function in innate and adaptive immunity has not been fully elucidated, particularly during immunization. Furthermore, the association between anti-SARS-CoV-2 specific IgG antibodies and ETE levels with vaccine responsiveness has not been investigated. MethodsThe present study explored the status of ETEs (Mn, Cu, Zn, and Se) in sera of healthy women before and after vaccination with the anti-SARS-CoV-2 BNT162b2 mRNA vaccine in a follow-up period of six months. The main aim was to explore links between ETE levels and IgG antibodies produced against Spike glycoprotein's Receptor-Binding Domain (RBD). ResultsA recombinant protein of SARS-CoV-2 comprising the receptor binding domain was successfully expressed in HEK-293 T cells. The purified protein was suitable for producing a sensitive antibody detection assay for human serum and monitored seropositivity, indicating a transient response with peak anti-SARS-CoV-2 IgG levels 2 months after vaccination. In parallel to increasing antibody titers, serum concentrations of Cu, Mn, and Se were not affected by vaccination, and concentrations remained relatively constant at the different sampling times during the 6-month observation period. Total serum Zn concentrations were slightly elevated when compared between the first and last sampling dates. Overall, no consistent effects of vaccination on any of the three trace elements analyzed in our study were observed. ConclusionVaccination of adult healthy female volunteers with an mRNA vaccine was not associated with consistent changes in serum trace element concentrations over a six-month observation period.

Bioleaching of metal(loid)s from sulfidic mine tailings and waste rock from the Neves Corvo mine, Portugal, by an acidophilic consortium

Sulfidic mine waste usually contains elevated amounts of valuable and hazardous metal(loid)s, which may pose environmental risks but can also provide opportunities for resource recovery. Reprocessing of mine waste can offer both economic and environmental benefits by supplying some of the ever-growing global demand for valuable metals, as well as reducing environmental risks. The present study aimed to simultaneously recover both valuable and hazardous metal(loid)s from two sulfidic mine waste samples (waste rock (NC_01) and tailings (NC_02)) from the Neves Corvo mine, Portugal, using a novel acidophilic consortium dominated by iron-oxidizing Leptospirillum genus and Acidiphilium sp. Bioleaching results showed that over 70% of the total Zn, Co, In, As, and Cd contents of NC_01 and NC_02 were leached within 21 days, while 55%–62% Mn was leached. Copper behaved in a refractory manner, as only 33% and 21% Cu were leached from NC_01 and NC_02, respectively. X-ray diffraction (XRD) and Scanning electron microscope-based automated image analyses (SEM/MLA-GXMAP) of the bioleached residues revealed an almost complete absence of residual pyrite in NC_01 and a reduction of pyrite in NC-02, as well as the formation of secondary minerals, especially jarosite. In most cases, the biogenic jarosite co-precipitated some of the leached elements again, e.g., Cu and Pb. In conclusion, a synchronized method for bioleaching valuable and hazardous metal(loid)s was developed using a novel acidophilic consortium, thereby demonstrating the potential for the generation of economic value and environmental risk reduction for sulfidic mine waste samples.