Low Chloride Concentrations Research Articles

(Invited) Sustainable Recycling of Metals from Solar Cells

The share of solar energy is increasing worldwide, leading to a widespread use of solar panels. Knowing that the 80 Mt of waste solar panels will be produced by 2050, sustainable processes must be designed in order to deal with the inevitable increase of waste solar cells in the coming years.The main advantage associated with recycling is to avoid the inevitable dispersion of hazardous materials in the environment occurring when the solar cells are landfilled. It also reduces the need for primary mineral resources and may reduce the supply risk for important components like silicon wafers, for which the production is concentrated in a few countries. The recycling process applied plays a major role to allow reducing the carbon footprint of solar cells, advocating in favour of sustainable practices for solar cells recycling.Mono-crystalline solar cells representing 90% of the market, it is therefore this kind of solar cells that are more likely to reach their end-of-life soon. Mono-crystalline solar cells are made of an aluminium frame surrounding the solar module. Underneath a glass layer, layers of ethylene vinyl acetate (EVA) encapsulate the solar cell. The solar cell in itself is made of a silicon wafer with aluminium and silver electrode as well as a silicon nitride anti-reflective coating. Recycling of the metals, particularly silver, is the main economic driver for solar cells recycling.Recycling mono-crystalline solar cells involves a mechanical removal of the aluminium frame and the junction box prior to removal of the glass and EVA layers. Different process were evaluated to get rid of EVA. Solvent-assisted dissolution allowed EVA dissolution but it requires the use of harmful solvents and often leads to breakage of the solar cell. Pyrolysis allows to recover the wafer intact while removing the glass and polymers layers. Provided that the thermal treatment is applied under an inert atmosphere, EVA decomposition leads to relatively non-toxic chemicals such as acetic acid. Recent developments include laser assisted would lead to efficient and straightforward removal of EVA.The removal of metals from the solar cells involves the use of harsh chemicals such as hydrofluoric acid for the removal of silicon nitride, nitric acid to solubilise silver and sodium hydroxide for the dissolution of aluminium. Recently, the use of aqueous brines was introduced to recover silver and aluminium from solar cells. A green and re-usable oxidising agent such as iron(III) chloride can be used to oxidise and dissolve silver, as evidenced in Figure 1, which shows a solar cells before (up) and after (down) etching, revealing the removal of the white silver lines.Using water as a solvent, silver dissolution is impossible due to the low chloride content. By increasing the chloride content, oxidation of silver and its dissolution becomes possible due to the formation of iron-chloride and silver-chloride complexes which have a different redox behaviour and a higher solubility. Overall, silver is completely dissolved in about 10 minutes without using any acids or harmful chemical. Silver can be easily recovered by precipitation or cementation, while the oxidising agent can be regenerated using oxygen from air or via electrolytic means. The objective of this presentation is to give an overview of the current recycling options and provide some guidance on the best and more sustainable practices for the complete recycling of solar cells. The choice is guided by techno-economic analysis and life cycle assessment as well as experimental demonstration of the recycling on real waste solar cells. Figure 1

Metalloproteomic Investigation of Hg-Binding Proteins in Renal Tissue of Rats Exposed to Mercury Chloride.

Results obtained from rat studies indicate that, even at low concentrations, mercurial species cause harmful effects on the kidneys, by inducing the nephrotic oxidative stress response. In the present work, Hg-associated proteins were identified as possible mercury-exposure biomarkers in rat kidneys exposed to low mercury chloride concentrations for 30 days (Hg-30) and 60 days (Hg-60), using metalloproteomic strategies. The renal proteomic profile was fractioned by two-dimensional electrophoresis and the mercury determinations in kidney samples, protein pellets and protein spots were performed using graphite furnace atomic absorption spectrometry. The characterization of Hg-associated protein spots and the analysis of differentially expressed proteins were performed by liquid chromatography, coupled with tandem mass spectrometry. Eleven Hg-associated protein spots with a concentration range of 79 ± 1 to 750 ± 9 mg kg-1 in the Hg-60 group were identified. The characterization and expression analyses allowed the identification of 53 proteins that were expressed only in the Hg-60 group, 13 "upregulated" proteins (p > 0.95) and 47 "downregulated" proteins (p < 0.05). Actin isoforms and hemoglobin subunits were identified in protein spots of the Hg-60 group, with mercury concentrations in the range of 138 to 750 mg kg-1, which qualifies these proteins as potential mercury-exposure biomarkers.

Investigation of the Diffusion of Chloride Ions in Blended Cement Pastes

AbstractWhen exposed to aggressive environments containing chlorides, the chlorine ion partially binds to the usual Portland cement mortar and changes its mineralogy. Chlorine ions entering the system displace sulfate from the monosulfoaluminate. Such systems form Kusel's salt at low chloride concentrations and Friedel's salt at higher concentrations. Unbound chloride ions remain dangerous for reinforcing steel, which diffuse deep into the concrete and destroy the passivating layer on the reinforcement. To assess the protective properties of concrete in relation to metal reinforcement, it is proposed to investigate the process of displacement of the diffusion front in cement composites of various compositions. It is also important to study changes in such characteristics as porosity and filtration properties, which significantly affect the penetration depth of an aggressive medium. The study of the structure, mineral and chemical composition is carried out in layers.

Urine sodium concentration after intravenous furosemide in dogs with acute congestive heart failure and correlation with treatment efficacy.

Poor natriuresis is a potential marker of diuretic resistance in dogs with acute congestive heart failure (CHF) but little is known about the relationship between urine sodium concentration (uNa) and frequency of successful decongestion. Supplemental O2 is a common treatment in dogs with severe CHF. The time from start to discontinuation of supplemental O2 therapy (DCSO2 ) typically reflects the time course and ease of decongestion. Urine Na concentration after IV administration of furosemide will be correlated with duration of treatment with supplemental O2 (timeO2 ) and the cumulative frequency of successful DCSO2 during hospitalization. Fifty-one dogs with acute CHF. Retrospective observational single center study. Dogs with low uNa had significantly longer mean timeO2 than dogs with high uNa (uNa <87 mmol/L, 24.2 ± 2.6 hours vs uNa ≥87 mmol/L, 16.6 ± 1.7 hours; P = .02). Low uNa was correlated with lower cumulative frequency of DCSO2 (12 hour, 28%; 24 hour, 42%; 36 hour, 73%) compared to high uNa (12 hour, 28%; 24 hour, 88%; 36 hour, 96%; P = .005). History of PO loop diuretics, low serum chloride concentration (sCl), and high PCV were associated with low uNa. Urine Na concentration outperformed other metrics of diuretic responsiveness including weight loss. Urine Na concentration after IV furosemide predicted timeO2 and cumulative frequency of DCSO2 in dogs with acute CHF, which likely reflects important aspects of diuretic responsiveness. Urine Na can assess diuretic responsiveness and treatment efficacy in dogs with CHF.

Migration pathway and solidification mechanism of heavy metal Pb during the conversion of municipal solid waste incineration fly ash into ettringite and simultaneously purification of chloride salts solution process

The solidification/stabilization of heavy metals and valuable component recovery from municipal solid waste incineration (MSWI) fly ash are of great significance for its safe disposal. In this study, MSWI fly ash was transformed into a new solid phase mainly composed of ettringite, achieving the solidification of excessive heavy metal Pb while obtaining a mixed solution of sodium chloride and potassium chloride with extremely low impurity content, which can be recovered by evaporation-crystallization respectively. The solidification mechanism of heavy metal Pb by ettringite was investigated through a combination of DFT calculations and experiments. The results indicate that a high conversion rate of calcium ions (99.68%), separation rate of chloride (95.99%), and conversion rate of heavy metal Pb (99.42%) can be achieved by controlling the ions ratio of the MSWI fly ash reaction system to n(Ca2+):n(Al3+):n(SO42−) = 6:2:3. DFT calculations show that the reaction pathway of the formation of a vacancy-Pb entering the vacancy at the Ca-2 site of ettringite is more likely to occur. The substitution of heavy metal Pb at the Ca-2 site leads to an increase in the unit cell volume, redistribution of charges, and a decrease in the thermal stability of the ettringite. The solidified body of ettringite presents a promising potential for application in cement-based materials due to its negligible risk of heavy metals leaching and low chloride content.

A superstable, flexible, and scalable nanofluidic ion regulation composite membrane

Two-dimensional layered membranes with high and stable ion transport properties have various applications in nanofluidic devices; however, their construction remains a considerable challenge. Herein, we develop a superstable aramid nanofiber/graphite composite membrane with numerous one-dimensional and two-dimensional nano-confined interspaces for ultrafast ion transport. The fabricated flexible and scalable membrane exhibits high tensile strength (∼115.3 MPa) even after immersion in water for 90 days. Further, the aramid nanofiber/graphite conductor features the surface-charge-governed ion transport behavior. The ionic conductivity of the membrane at a low potassium chloride concentration of 10−4 mol/L can be enhanced by 16 times that of the bulk counterpart. More importantly, its structure and ionic conductivity remain unchanged even after immersion in different harsh solutions (e.g., acid, base, and ethanol) for over 30 days. Molecular dynamics simulations reveal that the superstability of the membrane is attributable to the robust interchain interactions within the aramid nanofibers and the strong interfacial interactions between the aramid nanofibers and graphite nanosheets. This study highlights the superior structural stability of the proposed flexible and scalable aramid nanofiber/graphite composite membrane, which could be employed in advanced nanofluidic devices for application under extreme working environments.

Research on the Promotion of Sludge Anaerobic Fermentation with Sodium Citrate under Low Concentrations of Polyaluminum Chloride

Polyaluminum chloride (PAC) is used widely and increasingly in wastewater treatment plants, resulting in its inevitably high production in sludge. Previous studies have indicated that the production of short-chain fatty acids (SCFAs) is inhibited by the existence of PAC in sludge anaerobic fermentation, so it is necessary to study how to promote sludge anaerobic fermentation under low concentrations of PAC. In this study, sodium citrate (SC) was first used to improve the efficiency of anaerobic fermentation under low concentrations of PAC. The results showed that the production of SCFAs increased with SC, especially when the ratio of PAC to SC was 1:2, and the maximum production of SCFAs reached 2890 mg/L, which is 2.5 times more than when PAC only exists. The mechanism studies showed that SC could remove the Al3+ in the sludge floc, which led to deflocculation of the sludge floc, accelerated the destruction of extracellular polymers (EPS), and released soluble substances in the sludge. At the same time, the key enzymes that were bound and hidden originally in the sludge were also released, which promoted the further degradation of organic matter and shortened the anaerobic fermentation period. However, the higher concentration of SC was not conducive to sludge dehydration. Therefore, the optimal distribution ratio of PAC to SC should be 1:1. This study provides a new idea for the research and practical application of sludge anaerobic fermentation.

Evaluation of durability and microstructure evolution of chloride added fly ash and fly ash-GGBS based geopolymer concrete

The evaluation of corrosion behaviour of rebar and changes in microstructure evolution in geopolymer concrete (GPC) in the presence of chloride ions form an important aspect of durability investigation. For this purpose, an experimental investigation was undertaken to examine the corrosion of reinforcing steel and changes in microstructure development of fly ash based geopolymer concrete (FGC) and fly ash-GGBS based geopolymer concrete (FSGC) containing chloride ions. Corrosion behaviour was evaluated through corrosion potential (Ecor) and corrosion current density (Icor) and microstructural changes of GPC were examined at various ages and that at rebar level by XRD, EDS, FTIR, and FESEM analyses. Test results revealed that chloride ions had significant influence on consistency, strength, and microstructure of GPC. NaCl improved the consistency of GPC mixes. FSGC mixes showed 38.1% to 114.2% higher strength than FGC mixes at all ages irrespective of NaCl concentration. Further, GPC mixes exhibited lower strength with increase in NaCl concentration at all ages. Rebar embedded in FSGC specimens exhibited mostly less negative Ecor and lower Icor compared to FGC specimens. Results of chloride analysis revealed lack of chloride binding in GPC mixes. Higher peak intensity of aluminosilicate gels and presence of C-S-H gel in FSGC mixes as identified from XRD analysis and higher atomic Ca/Si ratio in FSGC mixes obtained from EDS analysis confirmed the improved performance of FSGC mixes in terms of higher strength, lower corrosion activity and lower chloride content over FGC mixes.

Co-pelletization of Hemp Residues and Agricultural Biomass: Effect on Pellet Quality and Stability

The rising interest in lowering the use of fossil fuels, which influence environmental pollution and global warming, is driving a substantial increase in renewable sources. Agricultural residues are the likely potential source for bioenergy generation. Some of them are already utilized for energy. Nonetheless, their potential is underutilized due to low biomass quality and high concentrations of sulfur and chloride, which induce the corrosion of adjoining equipment. However, their ash content and ash melting point make their utilization as renewable resources essential. Therefore, there is a need to find technologies to enhance biomass utilization for bioenergy processes. With the increase in hemp cultivation to extract phytocannabinoids, the amount of unused biomass has increased. The aim of this research was to investigate the use of hemp biomass for pellets and improve pellet quality by mixing them with lignin and oak sawdust. The results showed that the lowest amount of ash was found in pellets with 80% oak sawdust and 20% hemp residue compared with pellets made from mixtures of hemp residues, lignin, and oak sawdust. The highest calorific value was achieved by mixing hemp residues (20%) with lignin (80%).

In situ temperature-compensated ultraviolet spectrophotometry to estimate nitrate and chloride concentrations in estuarine seawater with different salinity and composition

Various methods have been proposed for in situ measurement of nitrate concentrations from the ultraviolet (UV) absorbance spectrum of seawater with stable salinity and constituents. However, salinity and temperature affect the UV absorption spectrum of seawater. In sea areas with large variability in salinity and water temperature, accurate nitrate ion concentration measurements remain challenging. We performed in situ measurements of nitrate, chloride, and bromide in estuarine seawater with different salinity compositions and applied water temperature compensation. First, the impact of water temperature on the UV absorbance of chloride, bromide, and nitrate was experimentally investigated and represented in a mathematical model. Next, chloride, bromide, and nitrate concentrations were estimated by suppressing the impact of residual components from the UV absorbance spectra of seawater using principal component regression (PCR). Hence, the chloride, bromide, and nitrate concentrations were determined by measuring the UV absorbance spectrum of seawater alone, without measuring water temperature and electrical conductivity. The proposed method was more accurate (±1.39 μM below 100 μM and ±0.90 μM below 20 μM) than the conventional method (±2.35 μM below 100 μM and ±1.88 μM below 20 μM) and PCR without water temperature compensation (±3.67 μM). In a field study, an in situ UV spectrophotometer with water temperature compensation was used to measure depth profiles of nitrate concentrations in estuarine seawater. We successfully measured the depth profiles of low chloride and high nitrate concentrations in the surface layer as well as high chloride and low nitrate concentrations in the lower layer. The proposed method enables in situ measurements of nitrate concentrations in waters with either stable or highly variable salinity and composition. Unlike conventional chemical analysis, our method can describe detailed spatiotemporal variations in nitrate concentrations.

Synergistic Binding of the Halide and Cationic Prime Substrate of l-Lysine 4-Chlorinase, BesD, in Both Ferrous and Ferryl States.

An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl- or Br-), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, the three nongaseous substrates must bind to activate the enzyme's Fe(II) cofactor for efficient capture of O2. Halide, 2OG, and (lastly) O2 all coordinate directly to the cofactor to initiate its conversion to a cis-halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H•) from the non-coordinating prime substrate to enable radicaloid carbon-halogen coupling. We dissected the kinetic pathway and thermodynamic linkage in binding of the first three substrates of the l-lysine 4-chlorinase, BesD. After addition of 2OG, subsequent coordination of the halide to the cofactor and binding of cationic l-Lys near the cofactor are associated with strong heterotropic cooperativity. Progression to the haloferryl intermediate upon the addition of O2 does not trap the substrates in the active site and, in fact, markedly diminishes cooperativity between halide and l-Lys. The surprising lability of the BesD•[Fe(IV)=O]•Cl•succinate•l-Lys complex engenders pathways for decay of the haloferryl intermediate that do not result in l-Lys chlorination, especially at low chloride concentrations; one identified pathway involves oxidation of glycerol. The mechanistic data imply (i) that BesD may have evolved from a hydroxylase ancestor either relatively recently or under weak selective pressure for efficient chlorination and (ii) that acquisition of its activity may have involved the emergence of linkage between l-Lys binding and chloride coordination following the loss of the anionic protein-carboxylate iron ligand present in extant hydroxylases.

Bicarbonate-Based Solution for the Management of Established Acute Kidney Injury: A Pilot Open-Label Observation Study.

Background Administration of intravenous (IV) solutions constitutes a key component of acute kidney injury (AKI) management. However, the optimal IV fluid solution in the setting of AKI remains uncertain. In this study, we assessed whether the use of bicarbonate-containing solution in patients with established AKI is associated with early renal recovery as compared to bicarbonate-free solutions. Methods We performed an open-label observational pilot study in 59 patients with established AKI. IV fluid solutions that were used include bicarbonate-based solution with low chloride content (80 mEq/L of 8% sodium bicarbonate in a solution that contains 77 mEq/L of sodium, 77 mEq/L of chloride and 25 g/L of glucose) or solutions without bicarbonate with high chloride content (0.9% normal saline, 0.45% half-saline, normal ringer, or 4% succinylated gelatine). We evaluated the association of IV fluids type with renal recovery. Results The median age of study participants was 66 years (inter-quartile range (IQR) 37-85), and 59% (n=35) were men. The prevalence of diabetes and chronic kidney disease (CKD) stages 1-3 were 34% (n=20) and 39% (n=23), respectively. Patients who received bicarbonate-based IV solutions had a greater reduction of serum creatinine (sCr) per day (delta sCr) as compared with patients who received bicarbonate-free solutions (-0.29±0.47 vs. 0.07±0.42; p=0.007). The renal recovery was faster in patients who received bicarbonate-based solutions as compared to the bicarbonate-free group (days from peak sCr to baseline sCr: 5.6±2.1 vs. 7.6±2.8; p < 0.001, respectively). Conclusions We observed faster renal recovery in patients with established AKI who received the bicarbonate-based solution with low chloride content. Our study findings require confirmation in larger cohorts.

Possible Zones of Submarine Groundwater Discharge (SGD) and Seawater Intrusion (SWI) along the West Coast of Kanyakumari, India

The possible zones of submarine groundwater discharge (SGD) and seawater intrusion (SWI) along the west coast of Kanyakumari in the southernmost Indian Peninsula were identified by integrating the surface temperature anomaly, water table fluctuation, and water quality analysis. Temperature map of the sea surface from Landsat 8 satellite data, which helped to demarcate SGD in areas with significant thermal contrast, exists between the seawater and discharging groundwater. Monitoring data of 2019–2021 illustrated patchy, diffuse, and temporally variable groundwater seepage. The spatial distribution map created from groundwater level, and water quality parameters depicted high SGD in areas of high groundwater level and high chances of SWI in regions with low groundwater level. This study identified that the areas with low groundwater level, high EC, and high chloride contents are prone to SWI. Similarly, the regions with high thermal contrast, high groundwater level, and low EC have more SGD. These methods have the potential to be used as preliminary screening tools before implementing detailed studies about the mixing process.

Effect of curing temperatures and additional activators on chloride ingress and its induced mineralogical alteration of ground granulated blast furnace slag activated by Ca(OH)2

The impact of additional activators (sodium sulfate, sodium nitrite, and calcium nitrite) and curing temperature (20 and 35 °C) on chloride binding and ingress resistance of ground granulated blast furnace slag activated by Ca(OH)2 was studied using X-ray diffraction, scanning electron microscopy, thermogravimetric and thermodynamic modeling. The outcomes of the study indicated that the difference in the chloride binding capacity at low chloride concentrations was primarily affected by the types of the AFm phase. The solid solution formed between Friedel's salt and various types of AFm phases resulted in a decrease in the chloride binding capacity. At a curing temperature of 35 °C, the chloride binding capacity reduced due to the leaching of calcium ions and carbonation induced by the coarse pore structure. It was found that the chloride ingress resistance was significantly related to the leaching of calcium and carbonation, and the denser calcite layer formed at the exposure layer had a positive impact on the chloride ingress resistance.

Effect of source and amount of rumen-protected choline on hepatic metabolism during induction of fatty liver in dairy cows

Objectives were to determine the effect of supplementing increased amounts of rumen-protected choline (RPC) from sources with low (L, 28.8%) or high (H, 60.0%) concentration of choline chloride on hepatic metabolism when cows were subjected to feed restriction to develop fatty liver. It was hypothesized that increased supplementation of RPC reduces hepatic triacylglycerol and enhances glycogen concentrations. Pregnant, nonlactating multiparous Holstein cows (n = 110) at mean (± standard deviation) 232 ± 3.9 d of gestation were blocked by body condition (4.01 ± 0.52) and assigned to receive 0 (CON), 12.9 (L12.9 or H12.9), or 25.8 (L25.8 or H25.8) g/d of choline ion. Cows were fed for ad libitum intake on d 1 to 5 and restricted to 50% of the NEL required for maintenance and pregnancy from d 6 to 13. Intake of metabolizable methionine was maintained at 19 g/d during the feed restriction period by supplying rumen-protected methionine. Hepatic tissue was sampled on d 6 and 13 and analyzed for triacylglycerol, glycogen, and mRNA expression of genes involved in choline, glucose, and fatty acids metabolism, cell signaling, inflammation, autophagy, lipid droplet dynamics, lipophagy, and endoplasmic reticulum stress response. Blood was sampled and analyzed for concentrations of fatty acids, β-hydroxybutyrate (BHB), glucose, triacylglycerol, total cholesterol, and haptoglobin. Orthogonal contrasts evaluated the effect of supplementing RPC [CON vs. (1/4·L12.9 + 1/4·L25.8 + 1/4·H12.9 + 1/4·H25.8)], source of RPC [(1/2·L12.9 + 1/2·L25.8) vs. (1/2·H12.9 + 1/2·H25.8)], amount of RPC [(1/2·L12.9 + 1/2·H12.9) vs. (1/2·L25.8 + 1/2·H25.8)], and interaction between source and amount [(1/2·L12.9 + 1/2·H25.8) vs. (1/2·H12.9 + 1/2·L25.8)]. Least squares means and standard error of the means are presented in sequence as CON, L12.9, L25.8, H12.9, H25.8. Supplementation of RPC reduced hepatic triacylglycerol (9.3 vs. 6.6 vs. 5.1 vs. 6.6 vs. 6.0 ± 0.6% as-is) and increased glycogen contents (1.8 vs. 2.6 vs. 3.6 vs. 3.1 vs. 4.1 ± 0.2% as-is) on d 13 of the experiment. Feeding RPC reduced serum haptoglobin (136.6 vs. 85.6 vs. 80.6 vs. 82.8 vs. 81.2 ± 4.6 µg/mL) during the feed restriction period; however, blood concentrations of fatty acids, BHB, glucose, triacylglycerol, and total cholesterol did not differ among treatments. During feed restriction, supplementation of RPC enhanced the mRNA expression of genes related to choline metabolism (BHMT), uptake of fatty acids (CD36), and autophagy (ATG3), and reduced the expression of a transcript associated with endoplasmic reticulum stress response (ERN1). An increase in the amount of choline ion from 12.9 to 25.8 g/d enhanced the mRNA expression of genes associated with synthesis and assembly of lipoproteins (APOB100), and inflammation (TNFA), whereas it reduced the expression of genes linked to gluconeogenesis (PC), oxidation of fatty acids (ACADM, MMUT), ketogenesis (ACAT1), and synthesis of antioxidants (SOD1) on d 13 of the experiment. Feeding RPC, independent of the product used, promoted lipotropic effects that reduced hepatic lipidosis in dairy cows.

Extraction and Characterization of Type I Collagen from Parrotfish (Scarus sordidus Forsskål, 1775) Scale solubilized with the Aid of Acetic Acid and Pepsin.

Waste from marine fish processing is an important source of valuable products. Fish collagen is considered a alternative biomaterial due to its excellent properties, and it is widely used for industrial purposes. Thus, this present study aimed to characterize acid and pepsin-soluble collagens from the waste of parrotfish (Scarus sordidus Forsskål, 1775) scales. The yields (p > 0.05) of acid-soluble collagen (ASC-PFS) and pepsin-soluble collagen (PSC-PFS) were 1.17 g/100 g and 1.00 g/100 g, respectively. Both collagen samples were categorized as type I owing to the presence of two alpha chain subunits (α1 and α1) after being confirmed by a sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Under the fourier transform infrared (FTIR) test, the triple helical structure of type I collagens from the ASC-PFS and PSC-PFS was maintained. Moreover, the study of UV visible spectra and X-ray diffraction (XRD) showed the similarity of collagens derived from different fish species, and the thermostability (T max) evaluation of all extracted collagens was in the range of 36.22-37.78°C, and their values were comparable to previous research on the fish scale collagens. The effect of various pH and sodium chloride (NaCl) treatments on solubility exhibited that the ASC-PFS and PSC-PFS were highly soluble in an acidic condition (pH < 5.0) and low concentration of sodium chloride (<30 g/L). Taken together, collagens extracted from parrotfish scale waste can be an alternative source for industries.

Modeling and Predicting Reduction Reaction Kinetics for a Stainless-Steel in NaCl Solutions

A method for analyzing cathodic polarization curves on stainless steels is described and a framework for predicting the cathodic polarization response for UNS S13800 is developed, including a model for the diffusivity of dissolved oxygen as a function of chloride concentration and temperature. The cathodic polarization behavior of UNS S13800 in NaCl solutions, ranging from dilute to saturated, and across a range of temperature values was studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). Analysis of the data indicated that the concentration of the solutions affected the ability of the oxide to catalyze reduction reactions. Dilute-to-low concentration solutions exhibited different Tafel slopes in the ORR-activation region while middle-to-high concentration solutions exhibited a single Tafel slope. The XPS and EIS results show a slightly thicker oxide formed in the low chloride concentration solutions over the course of the 18 hour open circuit duration along with a higher concentration of Fe3+ species.. The EIS data also showed the oxide formed in the low chloride solution had a higher charge-transfer resistance while the oxide formed in the high chloride solution had a higher oxide resistance.

Impact of Grass Pea Sweet Miso Incorporation in Vegan Emulsions: Rheological, Nutritional and Bioactive Properties

Grass pea (Lathyrus sativus L.) is a pulse with historical importance in Portugal, but that was forgotten over time. Previous to this work, an innovative miso was developed to increase grass pea usage and consumption, using fermentation as a tool to extol this ingredient. Our work's goal was to develop a new vegan emulsion with added value, using grass pea sweet miso as a clean-label ingredient, aligned with the most recent consumer trends. For this, a multidisciplinary approach with microbiological, rheological and chemical methods was followed. Grass pea sweet miso characterization revealed a promising ingredient in comparison with soybean miso, namely for its low fat and sodium chloride content and higher content in antioxidant potential. Furthermore, in vitro antimicrobial activity assays showed potential as a preservation supporting agent. After grass pea sweet miso characterization, five formulations with 5-15% (w/w) of miso were tested, with a vegan emulsion similar to mayonnaise as standard. The most promising formulation, 7.5% (w/w) miso, presented adequate rheological properties, texture profile and fairly good stability, presenting a unimodal droplet size distribution and stable backscattering profile. The addition of 0.1% (w/w) psyllium husk, a fiber with great water-intake capacity, solved the undesirable release of exudate from the emulsion, as observed on the backscattering results. Furthermore, the final product presented a significantly higher content of phenolic compounds and antioxidant activity in comparison with the standard vegan emulsion.

Groundwater characterization of the eastern Minesing Wetlands in support of the endangered Hine’s emerald dragonfly (Somatochlora hineana)

The Minesing Wetlands contain Canada’s only known population of Hine’s emerald dragonfly (HED), a species listed as endangered since 2011. The HED relies on groundwater discharge areas to complete its life cycle and therefore the population is potentially sensitive to changes in groundwater. The goals of this study were to, (1) characterize groundwater discharge to the eastern portion of the Minesing Wetlands, which corresponds to the HED habitat, (2) document any significant changes in groundwater chemistry since a 1998 study, and (3) establish a comprehensive baseline water quality data set to facilitate future comparisons. Consistent with HED habitats in the USA, the chemistry of Minesing Wetlands groundwater was dominated by calcium and bicarbonate. Low groundwater chloride and nitrate concentrations indicated minimal impact from activities such as road salt application and fertilizer use. Nitrate was generally only found at the wetland margin where groundwater springs emerged from the base of the uplands. The dominant form of inorganic nitrogen in wetland groundwater was ammonium (max = 1.5 mg N/L), and soluble reactive phosphorus concentrations were also relatively high (8 to 122 µg/L). The most consistent change in wetland groundwater chemistry between the 1998 study and samples collected in 2015–2017 was that chloride concentrations in 10 of 23 wells increased over time, however the maximum mean well chloride (11.6 mg/L) remained well below the guideline for the protection of aquatic life (120 mg/L). To preserve HED habitat, potential impacts to groundwater need to be considered during land use planning for the recharge area.

Physicochemical characteristics and heavy metals of groundwater during the wet and dry seasons at the Lafarge cement factory environment, Sagamu, Ogun State, Nigeria

AbstractThis study examined the physical, chemical, and heavy metals in groundwater from boreholes and hand‐dug wells at the Lafarge cement factory environment at Sagamu, Ogun State, Nigeria. Water samples were obtained from 20 sampling locations during the wet and dry seasons of 2019. The 17 parameters determined include the pH, temperature, electrical conductivity, total dissolved solids (TDS), total hardness, alkalinity, salinity, chloride, sulfate, phosphate, nitrate, calcium, magnesium, copper, lead, iron, and cadmium. The samples were analyzed using titrimetric and spectrophotometric methods. Correlation analysis was applied as part of the analytical tool in this study. The result indicated low physiochemical concentration of pH, total hardness, sulfate, nitrate, chloride, magnesium, calcium (&gt;1% to 15%), and electrical conductivity (&gt;1000 μS/cm) and fell within the Standard Organization of Nigeria (SON) and World Health Organization (WHO) desirable and maximum permissible limits for potable water during the wet and dry seasons. However, phosphate was above the standard limit for portable water of 6.5 mg/L in all sampling locations, whereas the total alkalinity was above the WHO standard limit (200 mg/L) in 12 locations in the wet seasons and a location in the dry season. Salinity was also above standards in one and four locations in the wet and dry seasons, respectively. Lead and cadmium were not detected in most locations, whereas iron, lead, cadmium, and copper were above standard limits in some locations. A significant relationship exists between the heavy metals and some of the physiochemical parameters at p ≥ .05 and p ≥ .01. The polluted water in most locations is capable of resulting in an adverse health hazard. Thus, this study explains the effect of physicochemical and heavy metals on water management at Sagamu and is important for water resource planning.