High Concentrations Of Ca Research Articles

Biogeochemistry of peat deposits of the Holocene section of the Vydrinsky bog (southern Baikal region)

Drilling cores from peat deposits of the Vydrinsky bog with a thickness of 4.4 m and an age of 13,100 cal. years, composed of lowland, transitional and high-moor types of peat, were studied in detail. The processes of post-sedimentary transformations of swamp sediments during early diagenesis are considered, the distribution of elements, the formation of authigenic minerals and the chemical composition of swamp waters are studied. The destruction of organic matter begins already in the upper intervals of peat at the early stages of diagenesis. Pyrograms do not have clearly defined high-temperature peaks, “rudiments” of the macromolecular structure of kerogen, which indicates a low degree of transformation of peat organic matter. A high number of organotrophic, ammonifying, nitrifying, phosphate-mobilizing microorganisms, a small number of Fe- and Mn-oxidizing microorganisms, and sulfate-reducing bacteria were revealed. The presence of organotrophic microorganisms throughout the section indicates that the biogeochemical processes of the carbon cycle cover the entire thickness of the peat deposit. A small amount of S (II) indicates a low intensity of sulfate reduction processes. Lowland peat is characterized by high contents of Si, Al, Fe, Ca, Sr, Ba, Zr, La and anomalous contents of Cu, Zn, which is a consequence of the formation of the bog under conditions of rich mineral nutrition. In the ash part of the transitional peat, a decrease in the contents of Si, Fe, Sr, Br, K Si, Ca, Ba, Cu, Zn and La is noted, which reflects the gradual weakening of the connection of the peat deposit with the underlying rocks. In the near-surface horizon of high-moor peat, there is an increase in the contents of K, Mn, Zn, Hg, Pb and As, which is associated with an increase in atmospheric dust and anthropogenic impact on the bog ecosystem in the 20th and 21st centuries. Bog waters of low-lying peat are characterized by high contents of the main ions, Al, Fe, Mn, Sr, while transitional peat is characterized by a decrease in DOC, SO42–, HCO3–, Al, Fe, Ni, Ca, Mg. The oligotrophic strata is characterized by the development of Fe oxides and hydroxides, the presence of vivianite is noted for transitional peats, and the eutrophic part of the peat deposit includes rhodochrosite and sulfides of Fe, Cu, and Zn.

Elemental Distribution in Tissues of Shorthorn Sculpins (Myoxocephalus scorpius) from Kongsfjorden in Svalbard

The shorthorn sculpin (Myoxocephalus scorpius) is considered a suitable sentinel species for marine pollution in the Arctic due to its ecology and stationary habits. To evaluate its role as a bioindicator for potential natural and anthropic impacts on the marine ecosystem of the Kongsfjorden (Svalbard, Norwegian Arctic), 33 female and male specimens of shorthorn sculpins were collected in July 2018 in proximity of the Ny-Ålesund international research facility and analyzed for the content of 25 major and trace elements and methylmercury (MeHg) in the muscle, liver, gonads, and gills by using spectroscopic techniques. Most elements had their maximum average concentrations in the gills (Al, Cr, Fe, Mn, Na, Ni, Pb, Se, Si, Sr, and V), while the livers featured higher contents of some toxic and heavy metals (As, Cd, Cu, Mo, and Zn). The muscle was characterized by high contents of Ca, K, and Mg, while Ba, Co, and P were mostly concentrated in the gonads. The gonads presented higher concentrations of Cr, K, Mg, Ni, P, and V for the males and Co, Cu, Fe, Mn, and Se for the females. Both the total Hg and MeHg concentrations in the muscle correlated with the fish size, indicating bioaccumulation, although high Se/Hg molar ratios (11.0 ± 2.2) suggested a low toxic potential of mercury.

Experimental study on disintegration of unsaturated red clay in Ca2+ solution environment

Guilin is a world-famous karst area characterized by a high concentration of Ca2+ in its groundwater. The disintegration of red clay plays a key role in the collapse of soil caves. In order to study the disintegration mechanisms of unsaturated red clay in Ca2+ solution, disintegration tests were conducted using a self-made disintegration apparatus. The soil samples are placed on the sieve plate of the disintegration apparatus, and a tensile meter records the real-time change of samples mass to calculate the disintegration rate. XRD analysis and filter paper method were employed to determine the mineral composition and matric suction of red clay, respectively. The results show that the matric suction decreases with increasing moisture content and increases with the void ratio. When the matric suction exceeds 965 kPa, disintegration is markedly intense, and the disintegration rate shows no significant correlation with Ca2+ concentration. When the matric suction is below than 965 kPa, the disintegration rate increases from 0.057 to 3.027 g/s with the increase of Ca2+ concentration. The disintegration of red clay with high matric suction is primarily attributed to the rapid ingress of water molecules and the compression of air due to matric suction, resulting in tensile stress. The disintegration of red clay with low matric suction is primarily caused by the reduction in the diffusion layer thickness of clay particles and the weakening of interparticle attraction due to Ca2+.

Strawberry Grown in an Indoor Vertical Farm Responds to Increased Photosynthetic Photon Flux Density When Calcium Is Supplied at Higher Concentrations

Indoor vertical farms can optimize light, temperature, humidity, and nutrient use, thus potentially maximizing crop growth and yield. However, the reported potential for enhanced crop growth and yield within these systems needs to be tempered against the understanding of the effects of this “forced growth”/optimal growth environment on “actual” plant performance to fully reap the benefits of these innovative vertical farming systems. We investigated the effect of calcium (Ca) on the production of strawberries in an indoor vertical farm system with varying photosynthetic photon flux density (PPFD). Fruit yield of plants fed with high Ca (9 meq·L−1) increased by 42.3% when the PPFD was 422 µmol·m−2·s−1; however, a subsequent increase to 572 µmol·m−2·s−1 resulted in a decline in fruit production. Plants treated with low Ca (5 meq·L−1) had a reduced yield and demonstrated no response to the PPFD. The observed increase in yield was associated with increased fruit production and total soluble solids. Plants exhibited 21.5% and 57.8% increases in the total dry weight when exposed to 422 and 572 µmol·m−2·s−1, respectively; however, Ca did not have any impact on this response. Independent of the Ca concentration, the photosynthesis rate increased by 16.1% and 22.2% when the PPFD increased to 422 and 572 µmol·m−2·s−1, respectively; however, the highest photosynthesis rate was recorded with 422 µmol·m−2·s−1 when the Ca level was 9 meq·L−1. High Ca-fed plants exhibited a reduction in Ca (−17.1%) content in their fruits when exposed to 572 µmol·m−2·s−1, which was likely caused by a dilution effect attributable to increased fruit biomass. In contrast, shoot Ca increased when plants were given high Ca when the PPFDs were 422 and 572 µmol·m−2·s−1. The Ca concentration in shoots correlated with the increasing yield, and a higher Ca concentration was associated with the increasing transpiration rate and stomatic conductance. Shoot phosphorus declined when plants were exposed to increased PPFD, and phosphorus was lower when plants were provided with 9 meq·L−1 of Ca; however, plants watered with low Ca solutions had more potassium. The shoot nitrogen content and micronutrient contents were unchanged regardless of the variations in PPFD or Ca. In summary, the favorable conditions for the cultivation of strawberry under controlled environments resulted in greater growth and fruit yield as long as Ca was provided at higher concentrations in the irrigation solutions (from 5 to 9 meq·L−1). We suggest that the higher demand of Ca that is necessary to satisfy the enhanced plant development observed in indoor farming systems may be connected to the role of Ca in the formation of new tissues, cell walls, and cell membranes.

Relationship of serum calcium concentration with chronic kidney disease and mortality in type 2 diabetes mellitus patients: evidence from the NHANES 1999-2018.

This study aims to explore the relationship of serum calcium (Ca) concentration with diabetic kidney disease (DKD) and all-cause mortality among type 2 diabetes mellitus (T2DM) patients using National Health and Nutrition Examination Surveys (NHANES). Data of T2DM patients aged ≥ 40 years were screened from the NHANES database from 1999 to 2018. The outcomes were the risk of DKD diagnosed by urine albumin-to-creatinine ratio (UACR) ≥ 30 mg/g or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 and the risk of all-cause mortality ascertained by linkage to National Death Index (NDI) records through 31 December 2019. The weighted univariate and multivariate logistic regression model and cox proportional hazard model were utilized to explore the relationships of serum Ca concentration with DKD and all-cause mortality, respectively, with odds ratios (ORs), hazard ratios (HRs) and 95% confidence interval. The relationships were further explored stratified by age, gender, body mass index (BMI), the duration of T2DM, and the history of cardiovascular disease (CVD), cancer and DKD. Totally, 6595 T2DM patients were included. Of these patients, 2441 (37.01%) had DKD and 1868 (28.32%) deaths occurred over a mean follow-up of 104.50 (± 1.61) months. In fully adjusted model, we observed high serum Ca concentration was associated with high risk of DKD (OR = 1.45, 95% CI 1.18-1.77) and high all-cause mortality risk (HR = 1.33, 95% CI 1.16-1.52). These relationships remained significant after performing subgroup analyses. The Restricted cubic spline curves shown that linear correlations were observed between serum Ca concentration and DKD as well as all-cause mortality (P < 0.05). Elevated serum Ca concentration may predict the high risk of DKD and poor prognosis in T2DM patients, and future large-scale and well-designed prospective cohort study is needed to explore the association of serum Ca concentration and DKD and prognosis in T2DM patients.

Flexible Hybrid Ceramic Composite Production From Hemp Oil And Waste Mussels/Egg Shells

Eggshells and mussel shells have become significant sources in the search for natural and renewable raw materials suitable for manufacturing flexible ceramic materials. This study enabled the development of flexible ceramic composites with polyvinyl alcohol (PVA) matrix using eggshell, mussel shell, and hemp oil. Scanning Electron Microscope (SEM) and energy dispersive spectroscopy (EDS) revealed the presence of dust particles obtained from the shells produced in composite films with high Ca content. X-ray diffraction (XRD) showed peaks belonging to calcite and aragonite phases and the prominent peak of PVA at 19.4°. All ceramic composite samples showed characteristic absorption peaks at about 1430, 860, and 710 cm−1 in Fourier Transform Infrared Spectroscopy (FTIR) analysis, which were attributed to the bending vibration and asymmetric stretching of CO32-, confirming the presence of CaCO3 in eggshell and mussel shell powders. The produced composite films have the most dramatic tensile strength of 17.06 MPa, and it has been identified that the strength decreased as the amount of powder increased. While the Shore-A hardness of the composites increased by 3.5 times with the increase in the amount of powder, their swelling rates decreased by 400%. The study sheds light on producing new-generation, eco-friendly, flexible ceramic composite materials.

Assessment of the water quality in the coastal Yaqui valley (Mexico): Implications for human health and ecological risks

This study examines the water quality in the Yaqui Valley in Mexico, a semi-arid region impacted by mining, agriculture, and aquaculture. Contamination sources, health risks and ecological impacts are investigated. Freshwater was found to be contaminated by dissolved As, presumed to result from mining activities in the mountains. Drainage water revealed an overall contamination by dissolved As and by suspended particles enriched with Al, Fe and Mn, associated with runoff processes. Intermittent contamination of drainage water by Cu, K+, NO3− and PO43− is attributed to the use of fertilizers or pesticides. In the coastal area, drainage water contains high concentrations of Na, Ca, SO42− and Cl, related to salinization processes, as well as higher concentrations of dissolved As, related to solid/liquid interactions that are enhanced by salinization. This drainage water discharges into the bay, degrading the seawater quality and increasing ecological risks. Outputs of this study can serve as a reference for the protection of this economically important coastal ecosystem. Concerning health risks, this study demonstrates that groundwater is also contaminated by dissolved As, believed to be associated with transfers from the geological basement to the dissolved phase of water, and other major chemicals related to salinization processes. The findings indicate that ingesting the groundwater poses a significant risk to human health with a primary exposure risk associated with dissolved As, particularly among children. This study presents crucial data for the Yaqui population, water managers and researchers, and provides novel insights into the management and mitigation of the identified risks.

Origin of the Oligocene–Miocene Sailipu ultrapotassic volcanic rocks in southern Tibet: Melting of Asian mantle pyroxenites triggered by eastward tearing of the subducting Indian continental slab

Widely distributed Oligocene−Miocene ultrapotassic volcanic rocks in the Lhasa terrane of southern Tibet have been associated with the melting of the lithospheric mantle, plateau uplift, and porphyry Cu-Au mineralization. This study presents the mineral chemistry of olivine and clinopyroxene phenocrysts, whole-rock major and trace element data, and zircon U-Pb geochronological and Hf isotopic data for the Sailipu primitive ultrapotassic volcanic rocks. The Sailipu volcanic rocks exhibit high MgO (5.6−11.4 wt%), Cr (386−981 ppm), Co (22−43 ppm), and Ni (95−423 ppm) concentrations and have highly fractionated rare earth elements [REEs; (La/Yb)N = 23−73] and high-Fo (89.1−90.8) olivine phenocrysts containing elevated NiO (up to 0.59 wt%), which suggests a pyroxenitic mantle source that partially melted in the garnet stability field. Their high K2O contents (4.8−8.0 wt%) and global subduction sediment-like trace element patterns suggest that the metasomatic agents, which reacted with mantle peridotites to form phlogopite-bearing pyroxenites, were dominantly derived from the melting of subducted continental sediments. Their high whole-rock Ba/La and Th/Nd ratios are consistent with this hypothesis. The Sailipu ultrapotassic volcanic rocks also exhibit low initial 176Hf/177Hf ratios that resemble those of Himalayan leucogranites, and high Ca contents in olivine phenocrysts, which is consistent with contributions from the subducted carbonate-rich sedimentary strata on top of the thinned Greater Indian continental crust. The zircon U-Pb chronological data yielded concordant ages of 24.33 ± 0.19 Ma, 21.20 ± 0.62 Ma, and 17.05 ± 0.31 Ma for different exposures of the Sailipu volcanic rocks, which establishes a maximum age of ca. 24 Ma for these rocks. The northwest−southeast spatial distribution and the southeastward decrease in age (80°E−90°E) suggest west-to-east tearing of the thinned Greater Indian slab, which caused asthenospheric upwelling and melting of the Tibetan lithospheric mantle. Geothermometric calculations show relatively high primary magma temperatures (∼1250 °C) that are consistent with asthenospheric upwelling. We propose a mechanism that could genetically link the coeval Cu-Au ore-forming granitoids with the ultrapotassic magmatism of the Gangdese belt. The ultrapotassic rocks supply a large-volume of external magmatic volatiles, particularly H2O, which could trigger melting of the Tibetan lower crust and lead to the generation of the ore-forming granitoids and the establishment of oxidizing conditions for porphyry deposits. The oxygen fugacity (log ƒO2 values of ΔFMQ) of the primitive Sailipu ultrapotassic volcanic rocks (ΔFMQ = 0.48 ± 0.51 based on the Dol/melt V oxybarometer and ΔFMQ = 0.33 ± 1.19 according to the magmatic zircon U-Ce-Ti oxybarometer) is slightly lower than that of porphyry Cu-Au ore-forming granitoids in the eastern Gangdese (ΔFMQ = +0.8 to +2.9), which suggests that the direct injection of ultrapotassic melts into ore-forming granitoids played a limited role in changing oxygen fugacity, but more oxidized fluids/volatiles exsolved from these ultrapotassic melts may have facilitated the remelting of sulfide-bearing lower crust and/or directly scavenged sulfides from the mush-state reservoirs of the ore-forming granitoids in the middle−upper crust.

The Relationship Standardized Precipitation Evapotranspiration Index (SPEI) and Forage Value of Rubus Species Collected from Türkiye’s Flora

The increasing drought caused by climate change makes it difficult for rural areas reliant on pasture-based livestock farming to sustain their agricultural practices. Blackberries, a spreading species, have been selected as the material for this study due to their perennial shrub nature and their tolerance to adverse environmental conditions. Türkiye, the gene center for blackberries, is part of the Mediterranean belt and is located at the intersection of three flora regions—Mediterranean, Euro-Siberian, and Irano-Turanian. This study aims to determine the forage value of the Rubus species and other shrub/tree species (Quercus, Pistacia, and Rosa) collected and identified from these flora regions. Furthermore, a linear regression analysis established a relationship between the forage values and the SPEI, a drought index, considering the combined effects of rainfall and temperature in the collection regions. Among the Rubus species, the highest organic matter content (887.8 g kg−1) was obtained from R. pruinosus. In comparison, the highest protein content (240.1 g kg−1) was found in cultivated blackberries in the Euro-Siberian flora region. P. lentiscus had the highest Ca content (14.4 g kg−1) and offered feed at the “Prime” level with 154 of RFV. The SPEI explained 87% of the variation in fructan, 89% in Mg, and 92% in ADF. Due to the perennial nature of the species studied, a strong relationship was found between their growth and forage values over a 48-month time scale using the SPEI. Consequently, the equations related to ADF, Mg, and fructan content obtained in this study can be recommended for woody species.

Effects of feed particle size, calcium concentration and phytase supplementation on InsP6 degradation in broiler chickens fed pelleted diets

ABSTRACT 1. The objective of the trial was to study the single and interactive effects of feed particle size in pelleted feed, dietary calcium (Ca) concentration and microbial phytase supplementation in broiler chickens. The studied traits were myo-inositol (1,2,3,4,5,6) hexakis (dihydrogen phosphate) (InsP6) degradation, pre-caecal digestibility of phosphorus (P), Ca and amino acids (AA) and retention of P, Ca and nitrogen (N). 2. Male Ross 308 broiler chickens were housed in metabolism units in groups of 10 and allocated to one of eight diets with seven pen replicates per diet. The 2 × 2 × 2-factorial arrangement included coarse and fine feed particle size (309 or 222 µm), low and high Ca concentration (4.9 and 7.2 g/kg) and without or with phytase supplementation (1,000 FTU/kg). 3. Pre-caecal InsP6 disappearance was higher with coarse than fine feed particle size when no phytase was added (54 vs. 48%) but not when phytase was added (74%; p = 0.046). High dietary Ca feeds decreased pre-caecal InsP6 disappearance (67 to 59%) and P digestibility (65 to 55%; p < 0.001). Gizzard pH was lower with coarse than fine feed particle size and higher with high Ca than low Ca (p < 0.001). Pre-caecal digestibility of most AA was approximately 3.5%-points lower with high Ca without phytase compared to the other treatments (p ≤ 0.047). Coarse feed particle size caused higher pre-caecal AA digestibility than fine particle size (~2%-points; p ≤ 0.031). InsP6 disappearance in the crop increased at high Ca concentration when phytase was added (22 vs. 37%; p = 0.011). 4. Coarser feed particle size in pellets increased gastrointestinal InsP6 degradation and nutrient digestibility, likely owing to effects on the gizzard functions. Additional Ca supply exerted antinutritive effects that was not compensated for by using coarser feed particles.

Study on the Chloride–Sulfate Resistance of a Metakaolin-Based Geopolymer Mortar

The chloride–sulfate corrosion environment of concrete is a significant engineering problem. This paper investigates the effect of the complete/semi–immersion mode on the durability of concrete in a chloride–sulfate environment by using different granulated blast furnace slag (GBFS) dosage rates (10–50%) of a metakaolin (MK)-based geopolymer mortar. The chloride–sulfate corrosion environment is discussed by analyzing the apparent morphology, mass change, and mechanical property change in specimens at the age of 120 d of erosion combined with XRD and SEM. The high Ca content in GBFS has an important effect on the strength and erosion resistance of the metakaolin geopolymer (MGP) group mortar; an increase in the GBFS dosage makes the MGP group mortar denser, and the initial strength of the MGP group mortar is positively correlated with the dosage of GBFS. After 120 d of erosion, the GBFS dosage is negatively correlated with erosion resistance, with the high GBFS dosage groups showing more severe damage. Semi-immersion resulted in more severe deterioration at the immersion–evaporation interface zone due to the difference in the ionic concentration and the ‘wick effect’ at the immersion–evaporation interface zone. Compared with the commonly used OPC mortar, the M40 and M50 groups have improved strength and corrosion resistance and are suitable for engineering environments in highly erosive areas.

Developing high elongation of Ca-containing Zn alloys with superior osteogenic and antibacterial properties

The development of high-strength zinc (Zn) alloys significantly contributes to the field of orthopedics by enhancing their osteogenic properties. Calcium (Ca) is pivotal for bone composition; however, its incorporation into the Zn matrix often hampers elongation due to the formation of large-sized CaZn13 phases. In this study, two Zn alloys with different Ca contents were prepared, and their microstructures, mechanical properties, corrosion behavior and biocompatibility were investigated. Results indicate that the Zn alloy with high Ca content exhibits large-sized and high-volume-fraction CaZn13 phases, which do not significantly change during equal channel angular pressing (ECAP). The grain sizes of ECAPed Zn alloys decreased from 36.75 μm and 35.81 μm of as-cast state to 4.32 μm and 1.71 μm, respectively. Refined microstructures contributed to the improvement of mechanical properties of Zn alloys, which have elongation over 15 % higher than that of all Zn-Mg-Ca alloys reported so far. The high elongation of Zn alloys originates from the inhibition of the propagation of microcracks which generated from the Zn/CaZn13 interphase. Moreover, the formation of large-sized CaZn13 phases leads to the severe local corrosion through enhancing galvanic effect, finally increasing corrosion rate. During degradation, the release of metallic ions, such as Zn2+, Mg2+, and Ca2+, are beneficial to the cell viability and osteogenic properties. And the accelerated release of Zn2+ plays a role in antibacterial performance. These results are very helpful for promoting the application of biodegradable Zn alloys in the field of orthopedics.

Assessment of variability for biochemical and mineral contents in fenugreek germplasm

Thirty accessions of fenugreek (Trigonellafoenum-graecumL.) were investigated for the morphological and proximate composition of (moisture, protein, phenols, total antioxidants and mineral contents) during 2022-2023 and 2023-2024. The genotypes showed a wide range of variations in the biochemical parameters. The fully mature leaves of fenugreek germplasm were subjected to biochemical analysis and revealed a wide range of variability in biochemical traits viz. Protein (3.19 to 5.57%) ascorbic acid content (31.8 to 82.5 ug/ g-1), phenol content (0.74 to 2.74 mg GAE g-1) and total antioxidants capacity (0.60 to 5.11 mg Trolox/g). EC 510685 was identified for green- copper color leaf with high antioxidant content of leaves ((5.11 mM Trolox/g), EC510717 was found rich in protein (5.5 %) and Zn content (1.12 mg/100 gm).EC510559 was reported to have higher Ca content (360mg100g-1) while EC510579 was observed with a higher test weight (20.15g). Significant differences were also recorded in mineral content viz. Ca (105 to 360mg/100 gm), Zn (0.34 to 1.2mg/100 gm) and mg (45.7 to 131mg/100 gm). Based on the evaluation superior genotypes identified can be exploited either for the promotion of antioxidants rich fenugreek, coloured leaves genotype for ornamental purposes and minerals-rich genotypes in the processing industry for fortification of fenugreek by developing products with other functional food to overcome malnutrition. This information could also be used to develop antioxidant-rich varieties through a suitable breeding approach.

International Simple Glass (ISG) dissolution rate in a (Si, Ca)-rich environment at 90 °C and alkaline conditions

The dissolution of International Simple Glass (ISG) was investigated at 90 °C and alkaline conditions with various concentrations of dissolved Si and Ca to unravel the combined effects of those elements on ISG reactivity. Experiments were conducted over durations ranging from 20 days to 3 months. Through morphological, structural, and chemical characterizations, the glass dissolution rate was proven to be strongly correlated with the activity of dissolved silica in the solution. While dissolved calcium did not significantly impact the dissolution rate, precipitation of calcium silicate hydrates (CSH) during the experiments enhanced ISG dissolution rate, though to a modest extent. The 3-months experiments highlighted the strong correlation between the dissolution mechanism and the evolution of the nature of secondary phases in saturated solution. During the first 20 days and at high Si and Ca concentrations, CSH precipitated and aggregated, without preventing the passivating impact of the gel layer at the surface of the glass: the dissolution was controlled by diffusion. Then, a resumption of dissolution occurred between 19 days and 76 days, corresponding to the CSH growth, and a possible mechanistic switch to a hydrolysis-controlled reaction rate. Finally, in some experiments, a drop in pH due to carbonate precipitation was observed along with a decrease in the dissolution rate, falling back in a diffusion-limited regime. Overall, this study shows that at 90 °C, pH = 10 and concentrations of SiO2(aq) exceeding 50 % of saturation with respect to amorphous silica, irrespective of Ca concentration but in presence of CO2(aq), ISG exhibits a very good chemical durability.

Biodiesel production, calcium recovery, and adsorbent synthesis using dairy sludge

Dairy sludge (DS) consists of organic compounds such as lipids and valuable inorganic elements. Biodiesel recovery from dairy sludge extract (DSE), using conventional acid (trans)esterification yielded only 16.5 wt%. In contrast, non-catalytic (trans)esterification generated a substantially higher biodiesel yield of approximately 74.0 wt% due to the method’s tolerance for impurities. Defatted dairy sludge (DDS) contained a higher Ca concentration than DS. DDS-produced biochar (DDSB) increased its Ca concentration predominantly in the form of CaO. 91.1% of the Ca was recovered from the DDSB containing Ca. The Ca remaining in the biochar residue (DDSBR) after Ca recovery was in the form of CaCO3. The porous structure developed as the Ca dissolved, implying that DDSBR could be an effective pollutant adsorbent. In this study, a method is proposed to maximize the utilization of DS by producing biodiesel, recovering Ca content, and using it as a pollutant adsorbent.

Effect of Specified pH Conditions on Leaching of Environmentally Important Major and Trace Elements from Fly Ash-Marl Mixtures: A Case Study of the Lignite Center of W. Macedonia

Significant environmental issues concerning the risk of soil, surface, and groundwater pollution are indicated by the presence of dissolved elements in the leachates. In the Lignite Center of Western Macedonia, the current study investigates the leaching behavior of main and trace elements from fly ash-marl mixtures, focusing on the effect of pH conditions on environmental impacts. Five mixtures of fly ash-marl were prepared in different percentage ratios by weight, simulating the possible deposition conditions to investigate the leaching of their contents in specified pH conditions. Initial fly ash is enriched in CaO, SO3, P2O5, and MgO, exceeding continental crust average composition in U, Br, Sb, Ni, Cd, W, and Mo. In contrast, the original marl is enriched in CaO and Ni but depleted in other major elements. The pH significantly affects leaching, with high concentrations of Ca2+ both in fly ash and in mixtures with high concentrations of fly ash, particularly at pH 8. Significant leaching of Cr and Ni is observed, with Cr mainly from fly ash at pH 10–12 and Ni increasing in marl at pH 6. The findings highlight the significant role of fly ash in the environmental element release and the importance of effective management.

Co-expression of endoglucanase and cellobiohydrolase from yak rumen in lactic acid bacteria and its preliminary application in whole-plant corn silage fermentation.

Endoglucanase (EG) and cellobiohydrolase (CBH) which produced by microorganisms, have been widely used in industrial applications. In order to construct recombinant bacteria that produce high activity EG and CBH, in this study, eg (endoglucanase) and cbh (cellobiohydrolase) were cloned from the rumen microbial genome of yak and subsequently expressed independently and co-expressed within Lactococcus lactis NZ9000 (L. lactis NZ9000). The recombinant strains L. lactis NZ9000/pMG36e-usp45-cbh (L. lactis-cbh), L. lactis NZ9000/pMG36e-usp45-eg (L. lactis-eg), and L. lactis NZ9000/pMG36e-usp45-eg-usp45-cbh (L. lactis-eg-cbh) were successfully constructed and demonstrated the ability to secrete EG, CBH, and EG-CBH. The sodium carboxymethyl cellulose activity of the recombinant enzyme EG was the highest, and the regenerated amorphous cellulose (RAC) was the specific substrate of the recombinant enzyme CBH, and EG-CBH. The optimum reaction temperature of the recombinant enzyme CBH was 60°C, while the recombinant enzymes EG and EG-CBH were tolerant to higher temperatures (80°C). The optimum reaction pH of EG, CBH, and EG-CBH was 6.0. Mn2+, Fe2+, Cu2+, and Co2+ could promote the activity of CBH. Similarly, Fe2+, Ba2+, and higher concentrations of Ca2+, Cu2+, and Co2+ could promote the activity of EG-CBH. The addition of engineered strains to whole-plant corn silage improved the nutritional quality of the feed, with the lowest pH, acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents observed in silage from the L. lactis-eg group (p < 0.05), and the lowest ammonia nitrogen (NH3-N), and highest lactic acid (LA) and crude protein (CP) contents in silage from the L. lactis-eg + L. lactis-cbh group (p < 0.05), while the silage quality in the L. lactis-cbh group was not satisfactory. Consequently, the recombinant strains L. lactis-cbh, L. lactis-eg, and L. lactis-eg-cbh were successfully constructed, which could successfully expressed EG, CBH, and EG-CBH. L. lactis-eg promoted silage fermentation by degrading cellulose to produce sugar, enabling the secretory expression of EG, CBH, and EG-CBH for potential industrial applications in cellulose degradation.

Reduction Removal of Cr(VI) Using Oxalic Acid With MOF‐525(Fe) as Catalyst: Performance and Mechanism

ABSTRACTHexavalent chromium (Cr(VI)) has attracted great considerations due to their high toxicity, teratogenicity, and carcinogenicity. In this study, four Zr‐MOFs were synthesized and used to comparative study their catalytic performances of oxalic acid (OA) for Cr(VI) removal. Results showed that the removal efficiency for Cr(VI) was reached 65.91%, 78.64%, 53.58%, and 96.32% by MOF‐525, MOF‐525(Co), MOF‐525(Zn), and MOF‐525(Fe) in the presence of OA when the initial Cr(VI) concentration was 100 mg·L−1, respectively. The single‐factor experiments for further improving the Cr(VI) removal by MOF‐525(Fe)/OA demonstrated that the optimal conditions were OA dosage of 790 mg·L−1, and MOF‐525(Fe) dosage of 500 mg·L−1 and pH of 2.0, and the MOF‐525(Fe)/OA system could be used to treat Cr(VI)‐containing wastewater at concentrations below 50 mg·L−1. Ionic strength studies indicated that Na+, K+, Mg2+, Cl−, and SO42− had little effect on the catalytic reduction of Cr(VI), while high concentrations of Ca2+ (0.10 and 0.25 mol·L−1), NO3− (0.25 mol·L−1), and PO43− (0.25 mol·L−1) had significant inhibition effects. The reusability experiments showed that the stability of MOF‐525(Fe) was excellent, and it could be used for potential applications. Based on the results of Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and Electron Paramagnetic Resonance spectrometer (EPR), the possible reduction mechanism of Cr(VI) by MOF‐525(Fe)/OA system was proposed as follows: The complexation of OA with Fe3+ was first complexed to produce Fe2+ and CO2•−, then Cr(VI) was combined with Zr–O and Fe–O clusters in MOF‐525(Fe) to obtain activation energy, and the reduction ability was enhanced at the same time; finally, Cr(VI) obtained electrons from CO2•− and was sequentially reduced as Cr(V) and Cr(III).

Phenotypic and Biochemical Trait Improvement in Husk Tomatoes (Physalis sp.) through EMS-Induced Mutagenesis

Husk tomatoes are used in salsa and traditional medicine to alleviate illnesses. Market demand requires husk tomato varieties with improved agronomic and physicochemical health benefits. Mutagen application alters plant genomes, creating new traits and genetic diversity. The efficacy of EMS (ethyl methanesulfonate) was examined for morphology, bioactive compounds, and phytochemical improvement. Three husk tomato genotypes representing Physalis philadelphica and Physalis ixocarpa underwent two hours of 1.4% EMS. In addition to yield and yield-related properties, total phenol, antioxidant activity, chlorophyll a and b levels in leaves and fruits, and phytochemical concentrations of Na, Mg, Ca, Mn, Fe, Cu, and K in fruits were measured. Genotype-dependent morphological changes were found. The mutants C1T6 (85 cm) and C1T7 (87.60 cm) were shorter than Control C1 (102 cm). The highest yield was 5.80 g for C1T5; Control C1 produced 3.08. The mutant C2T6 produced the most (5.99 g) compared to its control (2.85 g). Mutants had higher total phenol, antioxidant activity, and leaf/fruit chlorophyll. C1T2 had the highest antioxidant activity (1.19 ng/µL). C2T1 outperformed Control C2 at 1.54 ng/µL phenolic content. C3T2 had the highest Ca content (1822 µg/g), while Control C3 had 861.20 µg/g. Mutations altered phytochemical composition, which can be used to generate nutritionally superior husk tomato varieties. Additionally, scientists will be able to study mutants with advantageous morphological and biochemical traits, enabling extensive research. Furthermore, the mutants will serve as a genetic repository for the progression of breeding procedures.

Gluconate and formate uptake by hydrated cement phases

The uptake of formate and gluconate by C–S–H, AFm phases, ettringite and hydrated Portland cement (PC) was studied at pH 13 by batch sorption experiments. The formation of gluconate and formate-AFm phases was observed in pure systems, but not in hydrated cement. Gluconate sorbs more strongly on AFm phases and ettringite than formate. Higher calcium concentrations increase the gluconate sorption on C–S–H and hydrated Portland cements due the formation of Ca-gluconate surface complexes on C–S–H. Measured Rd values for gluconate sorption on C–S–H increase from 2.0 dm3‧kg−1 for C–S–H with Ca/Si = 0.8 to 34 dm3‧kg−1 for Ca/Si = 1.4 at pH 13. They are a factor 5 to 10 higher at lower pH values, and higher Ca-concentrations. Calcium concentration does not significantly affect the uptake of formate by C–S–H. Formate sorbs on hydrated PC with Rd values in the range of 3–33 dm3‧kg−1.