Physicochemical Measurements Research Articles

Taxonomic variability and functional stability across Oregon coastal subsurface microbiomes

The factors shaping microbial communities in marine subsurface sediments remain poorly understood. Here, we analyzed the microbiome of subsurface sediments within a depth range of 1.6–1.9 m, at 10 locations along the Oregon coast. We used metagenomics to reconstruct the functional structure and 16S rRNA gene amplicon sequencing to estimate the taxonomic composition of microbial communities, accompanied by physicochemical measurements. Functional community structure, in terms of the proportions of various gene groups, was remarkably stable across samples, despite the latter covering a region spanning over 300 km. In contrast, taxonomic composition was highly variable, especially at the level of amplicon sequence variants (ASVs) and operational taxonomic units (OTUs). Mantel correlation tests between compositional dissimilarities and geographic distances revealed only a moderate influence of distance on composition. Regression models predicting taxonomic dissimilarities and considering up to 20 physicochemical variables as predictors, almost always failed to select a significant predictor, suggesting that variation in local conditions does not explain the high taxonomic variability. Permutation null models of community assembly revealed that taxa tend to strongly segregate, i.e., exclude each other. We conclude that biological interactions are important drivers of taxonomic variation in subsurface sediments, and that this variation can decouple from functional structure.

Harnessing Deep Learning for Real-Time Water Quality Assessment: A Sustainable Solution

This study presents an innovative approach utilizing artificial intelligence (AI) for the prediction and classification of water quality parameters based on physico-chemical measurements. The primary objective was to enhance the accuracy, speed, and accessibility of water quality monitoring. Data collected from various water samples in Algeria were analyzed to determine key parameters such as conductivity, turbidity, pH, and total dissolved solids (TDS). These measurements were integrated into deep neural networks (DNNs) to predict indices such as the sodium adsorption ratio (SAR), magnesium hazard (MH), sodium percentage (SP), Kelley’s ratio (KR), potential salinity (PS), exchangeable sodium percentage (ESP), as well as Water Quality Index (WQI) and Irrigation Water Quality Index (IWQI). The DNNs model, optimized through the selection of various activation functions and hidden layers, demonstrated high precision, with a correlation coefficient (R) of 0.9994 and a low root mean square error (RMSE) of 0.0020. This AI-driven methodology significantly reduces the reliance on traditional laboratory analyses, offering real-time water quality assessments that are adaptable to local conditions and environmentally sustainable. This approach provides a practical solution for water resource managers, particularly in resource-limited regions, to efficiently monitor water quality and make informed decisions for public health and agricultural applications.

Investigation of Nickel-Based Gas Diffusion Electrodes for Implementation in a Hybrid Alkaline Water Electrolysis Cell

Substantial amounts of green hydrogen will be required for the transformation of several industry sectors toward a more sustainable operation. The future chemical industry, in particular, will be in high demand since the environmental impact of processes like ammonia and methanol synthesis can be significantly reduced via the use of green hydrogen. Moreover, hydrogen is one possible option for storing surplus electrical energy, the production of which is unavoidable when switching to renewable sources of electricity [1].Among the different available technologies, Alkaline Water Electrolysis (AEL) is the most cost-effective and developed variant [2]. However, conventional AEL encounters challenges such as a significant gas cross-contamination, especially in the part-load range [3]. A novel hybrid cell arrangement proposed by Koj et al. [3] (Fig. 1 (a)) aims for mitigation of these cross-contaminations by implementing gas diffusion electrodes (GDEs). As an additional benefit, only one instead of two electrolyte cycles is needed. This simplifies the electrolysis system noticeably.In this work, the development and employment of GDEs for the oxygen evolution reaction (OER) in the hybrid cell arrangement will be investigated. The developed electrodes are based on prior research of Kaiser et al. [4]. The GDEs are manufactured by spray-coating nickel mesh with a mixture of catalyst components dispersed in water. The catalyst is mainly composed of nickel particles, with low amounts of iron as a secondary catalyst to enhance the electrode performance [4]. PTFE acts as the binder, while methyl cellulose is used as a pore-building agent. A sintering step creates the necessary porous structure by removing the methyl cellulose and melting the PTFE. A typical GDE structure of hydrophilic and hydrophobic pores is created in the process.This study investigates the impact of each catalyst component and additional variables such as the catalyst load on the electrode performance. The main point of consideration is the mass fraction of each component, which is varied systematically. Multiple electrochemical (linear sweep voltammetry, electrochemical impedance spectroscopy, chronopotentiometry, cyclic voltammetry) and physicochemical measurements (BET surface area, porosity, pore size distribution, bubble point) are conducted. Fig. 1 (b, c) illustrates the effect of methyl cellulose content and catalyst loading and their subsequent effect on the electrode performance, as shown exemplary with linear sweep voltammetry measurements. The GDEs appear to benefit from a higher methylcellulose content and a higher catalyst load. The collected data can be used to determine an optimal catalyst composition. Furthermore, the connections between physical structure, catalyst composition and electrode performance are to be unraveled. Subsequent research will focus on evaluating electrodes with optimal parameters in a full-cell setup, specifically addressing cell voltage, stability and the overall goal of reducing the gas cross-contamination.Literature:[1] M. Yue, H. Lambert, E. Pahon, R. Roche, S. Jemei, D. Hissel, Renewable and Sustainable Energy Reviews 146, 2021.[2] A. Buttler, H. Spliethoff, Renewable and Sustainable Energy Reviews 82(3) 2018.[3] M. Koj, J. Qian, T. Turek, International Journal of Hydrogen Energy 44(57) 2019.[4] M. Kaiser, F. Gäde, J. Brauns, T. Turek, Catalysts 13(9) 2023. Figure 1

Effect and mechanism of short time ball milling on physicochemical characteristics and pyrolysis kinetics of Pennisetum giganteum

This study investigated the variation of biomass pyrolysis kinetics with changes in ball milling (BM) intensity. Pennisetum giganteum was used as the pyrolysis sample, and different BM times were set to alter the BM intensity. A comprehensive analysis was carried out, combining physicochemical property measurements and pyrolysis experiments. The results showed that BM could change the sample’s particle size (1770–30.80 μm), specific surface area (0.0291–0.7554 m²/g), and pore volume (0.103–2.207 mm³/g) within a very short time (≥2 min). Interestingly, only a long BM duration (20 min) significantly reduced the sample’s crystallinity. The activation energy vs. conversion rate curve of the samples transitioned from being tangential to being parabolic as the duration of BM increased, with a notable change in the average activation energy observed after BM 20 min (152.65–135.50 kJ/mol). This was caused by the destruction of crystalline cellulose into amorphous cellulose, which reduced the thermal stability of the sample. Furthermore, changes in other physicochemical properties had no significant impact on the pyrolysis average activation energy. This study provided valuable references for the optimization of pretreatment parameters in pyrolysis production.

General selection criteria for safety and patient benefit [XⅢ]: Comparing the formulation characteristics of brand-name and generic bifonazole creams.

A comparative evaluation of the brand-name drug Mycospor and six generic drugs (IWAKI, Bifonol, F, YD, Sawai, and TEVA), all comprising a cream formulation containing the antifungal drug bifonazole, was performed based on physicochemical measurements. The pH of the various formulations was significantly higher for the generics Bifonol (pH 7.1), Sawai (pH 6.7), and TEVA (pH 7.3) and significantly lower for YD (pH 4.3) than for the brand-name drug Mycospor (pH 5.5). The viscosity of the various formulations was significantly higher for TEVA (25,011 mPa·s) versus Mycospor (22,376 mPa·s) and significantly lower for IWAKI, Bifonol, F, YD, and Sawai, with Bifonol (8,572 mPa·s) being particularly low. Considering the hysteresis loop area obtained for the shear rate vs. shear stress, which represents the thixotropic properties, and using the value of Mycospor as the reference for 100%, YD (179%), Sawai (557%), and TEVA (201%) showed significantly higher values. Furthermore, the membrane permeability of bifonazole at 24 hours was significantly higher for Bifonol (309 μg/mL) and F (182 μg/mL) and significantly lower for Sawai (124 μg/mL) and TEVA (92 μg/mL) than for Mycospor (153 μg/mL). Finally, optical micrographs showed that the dispersion of particles was similar in the various formulations, but the particles of F and TEVA were uniformly dispersed with a smaller particle size than the other formulations. Overall, significant differences were observed in the formulation characteristics between the brand-name drug and generic drugs, which were attributed to differences in the manufacturing process and the types of additives.

High-capacity, fast-charging and long-life magnesium/black phosphorous composite negative electrode for non-aqueous magnesium battery

Secondary non-aqueous magnesium-based batteries are a promising candidate for post-lithium-ion battery technologies. However, the uneven Mg plating behavior at the negative electrode leads to high overpotential and short cycle life. Here, to circumvent these issues, we report the preparation of a magnesium/black phosphorus (Mg@BP) composite and its use as a negative electrode for non-aqueous magnesium-based batteries. Via in situ and ex situ physicochemical measurements, we demonstrate that Mg ions are initially intercalated in black phosphorus two-dimensional structures, forming chemically stable MgxP intermediates. After the formation of the intermediates, Mg electrodeposition reaction became the predominant. When tested in the asymmetric coin cell configuration, the Mg@BP composite electrode allowed stable stripping/plating performances for 1600 h (800 cycles), a cumulative capacity of 3200 mAh cm−2, and a Coulombic efficiency of 99.98%. Assembly and testing of the Mg@BP | |nano-CuS coin cell enabled a discharge capacity of 398 mAh g−1 and an average cell discharge potential of about 1.15 V at a specific current of 560 mA g−1 with a low decay rate of 0.016% per cycle for 225 cycles at 25 °C.

Spatiotemporal variation of macroinvertebrate communities in relation with water quality in urban rivers of Adwa, Northern Ethiopia

ABSTRACT Macroinvertebrates are bio-indicators of environmental health. A study on spatiotemporal diversity and abundance of macroinvertebrates was conducted in two rivers of Adwa, Ethiopia. Samples were collected from each river following the multi-habitat sampling approach. Moreover, physicochemical measurements were also taken. A total of 892 specimens of macroinvertebrates belonging to three phyla, eight orders and 17 families were identified. Higher (98%) and lower (2%) taxonomic abundance was recorded during the dry and wet seasons, respectively. Family Physidae (48.65%) was the most dominant followed by Planorbidae (21.74%). During the dry and wet season Adi Haki river AD1 had the highest (H = 1.615) and lowest (H = 0.651) diversity index, respectively. Physicochemical measurements showed no significant difference between the two rivers (p > 0.05). The results of the study shows that the study rivers have moderate environmental health status. Therefore, watershed management is important to keep the area healthy.

Novel CD44-Targeted Albumin Nanoparticles: An Innovative Approach to Improve Breast Cancer Treatment.

This study introduces novel CD44-targeted and redox-responsive nanoparticles (FNPs), proposed as doxorubicin (DOX) delivery devices for breast cancer. A cationized and redox-responsive Human Serum Albumin derivative was synthesized by conjugating Human Serum Albumin with cystamine moieties and then ionically complexing it with HA. The suitability of FNPs for cancer therapy was assessed through physicochemical measurements of size distribution (mean diameter of 240 nm), shape, and zeta potential (15.4 mV). Nanoparticles possessed high DOX loading efficiency (90%) and were able to trigger the drug release under redox conditions of the tumor environment (55% release after 2 h incubation). The use of the carrier increased the cytotoxic effect of DOX by targeting the CD44 protein. It was shown that, upon loading, the cytotoxic effect of DOX was enhanced in relation to CD44 protein expression in both 2D and 3D models. DOX@FNPs significantly decrease cellular metabolism by reducing both oxygen consumption and extracellular acidification rates. Moreover, they decrease the expression of proteins involved in the oxidative phosphorylation pathway, consequently reducing cellular viability and motility, as well as breast cancer stem cells and spheroid formation, compared to free DOX. This new formulation could become pioneering in reducing chemoresistance phenomena and increasing the specificity of DOX in breast cancer patients.

Hydroxylation of Phenol by an Azomethine Quinoxaline Schiff Base Copper (II) Complex

Introduction: A binuclear azomethine quinoxaline Schiff base copper (II) complex, [Cu2LCl2], having square-planar environment around each copper (II), has been synthesized. Method: The coordination of the azomethine quinoxaline Schiff base with copper (II) and its structure was studied by various physicochemical and spectroscopic measurements. Results: Catalytic activity of this complex in phenol hydroxylation reaction has been examined using H2O2 as a green oxidant. Conclusion: Catalytic reaction conditions were optimized and under these conditions, 18.32 % conversion of phenol has been obtained for this catalyst

Understanding the electrochemical processes of SeS2 positive electrodes for developing high-performance non-aqueous lithium sulfur batteries

SeS2 positive electrodes are promising components for the development of high-energy, non-aqueous lithium sulfur batteries. However, the (electro)chemical and structural evolution of this class of positive electrodes is not yet fully understood. Here, we use operando physicochemical measurements to elucidate the dissolution and deposition processes in the SeS2 positive electrodes during lithium sulfur cell charge and discharge. Our analysis of real-time imaging reveals the pivotal role of Se in the SeS2 nucleation process, while S enables selective depositions. During the initial discharge, SeS2 converts into Se and S separately, with the dissolved Se acting as nucleation sites due to their lower nucleation potential. The Se effectively catalyzes the growth of S particles, resulting in improved lithium sulfur battery performance compared to cells using positive electrodes containing only Se or S as active materials. By adjusting the Se-to-S ratio, we demonstrate that a low concentration of Se enables uniform catalytic sites, promotes the homogeneous distribution of S and favours improved lithium sulfur battery performance.

Ökologische Zeigerwerte der Gefässpflanzen Österreichs

Abstract Ecological indicator values for Austrian vascular plants. Ecological indicator values of plants serve as indirect indicators for the status of ecological parameters in absence of physico-chemical measurements at place. Ellenberg introduced seven parameters which are namely light (L), temperature (T), continentality (K), moisture (F), reaction (R), nutrients (N), and salt (S), to define optima of plant growth under natural conditions along gradients scaled to nine levels. The moisture gradient is even extended to twelve levels and additional codes give information about the tolerance of facultative flooding or seasonal drought. Species that lack distinct optima and are present over a zone of more than four levels of the respective gradients are called indifferent (i). Plants that show optima situated towards both ends of the scale for parameters F and R are classified as bimodal (b) for the first time in national records of indicator values. Broad amplitudes and indistinct optima of species presences along the scales are not indicated separately due to the lack of available data. For 4902 vascular plants we provide indicator values that are valid for the Republic of Austria (holds for L, T, F, R, N, S). The values for continentality (K) consider the whole distribution area of the species. Comparisons with indicator value systems from neighboring countries show some shifts in the number of species assigned to the indicator levels but the histograms do not differ very much. Apparently, such shifts depend on the length of the ecological gradients available in the respective region but also on the regional pool of species and subspecific ecotypes.

Classification of select functional dietary fiber ingredients based on quantitative properties and latent qualitative criteria.

Functional dietary fiber ingredient (FDFI) functionality can depend on the fibers' chemistry, composition, size, botanical origin, and microstructure. However, such claims have never been generalized for a broad range of fibers in one study before. To support these claims, 23 FDFIwere characterized based on 11 physicochemical, physical, and compositional property measurements: Water- and oil-holding capacity (WHC and OHC), water absorption and solubility indices (WAI and WSI), flour-swelling potential (FSP), particle size distribution (D10, D50, and D90 values), and soluble, insoluble, and total dietary fiber content. Multivariate statistical techniques were employed to partition fiber ingredients into functional categories based on these quantitative data, and scanning electron microscopy was used to examine the microstructure of the FDFI. Strong correlations (p<0.05) were found among many of the physicochemical properties measured, and five categories based on quantitative physicochemical functionality, size, and fiber composition were ultimately found. Distinct patterns emerged between these quantitative partitions and the latent microstructure features and botanical origins of the FDFI. These results can be combined into one intuitive summary of FDFI functionality based on the described quantitative and qualitative observations. Such summaries are useful for ingredient suppliers or product developers with limited resources to infer the general functionality, structure, and food applications utility of their materials based on a subset of the information provided here. PRACTICAL APPLICATION: The quantitative and qualitative relationships among a range of commercially available functional dietary fiber ingredients are documented. Industry may utilize this information to predict the general functionality of their ingredients based on a subset of the information provided here by assuming that the same relative relationships will exist. This cansave time during the ingredient screening process, either for product developers looking to optimize a formulation or for ingredient suppliers doing new ingredient applications testing.

Unraveling The Impact of Feed Protein Content on Catfish (Clarias sp.) Growth, Survival, Meat Quality and Gastrointestinal Histology

Catfish is a highly favored source of protein in Indonesia. Catfish farming can be carried out using various types of feed and methods. This research aims to determine the effect of two types of fish feed with high (24%) and low (4%) protein content on several aspects of catfish cultivated using the pond/bucket culture method. The methods include catfish maintenance, physicochemical measurement, morphometric measurements, survival rate measurements, proximate testing, and histological preparations of catfish intestines and stomach. The results show that the TDS and pH values in the high-protein feed are higher than in the low-protein feed, while the temperature fluctuates. At the end of the observation, there is a significant difference in the morphometry of catfish fed with high-protein feed, where the body weight, head width, and body length are higher. The difference in body weight of catfish fed with high-protein feed is significantly higher (119.58±16.72 g) compared to those fed with low-protein feed (52.20±4.80 g). The average number of surviving catfish fed with high-protein feed is lower (27.60±8.23 fish) compared to the other group (44.00±2.55 fish). Proximate testing indicates that catfish meat with high-protein feed also has higher protein, fat, and carbohydrate content. Histological analysis shows that catfish with high-protein feed have longer villi and higher number of goblet cells, while the length of the gastric pits is lower. This research demonstrates that high-protein feed has an impact on fish quality, while ensuring water quality to reduce catfish mortality rates in catfish pond culture.

Radioactivity as a driver of bacterial community composition in naturally radioactive mineral springs in the French Massif Central.

Some natural environments on Earth are characterised by high levels of radiation, including naturally radioelement enriched mineral springs in the French Massif Central. Therefore, naturally radioactive mineral springs are interesting ecosystems for understanding how bacterial populations in these springs have adapted to high levels of natural and chronic radioactivity over the very long term. The aim of this study was to analyse the bacterial communities of sediments from five naturally radioactive mineral springs in the French Massif Central, sampled in autumn 2019 and spring 2020, and to observe whether radionuclides, compared to other physicochemical parameters, are drivers of the bacterial community structuring in these extreme environments. Physicochemical measurements showed that two springs, Dourioux and Montagne had high radioelement concentrations/activities (uranium, thorium and radon). Analysis of the structure of the bacterial communities, by next generation sequencing based on 16S rRNA gene sequencing, showed that the presence of radionuclides in Dourioux and Montagne, did not lead to a reduction in bacterial diversity and richness compared to the other springs. However, Dourioux and Montagne were characterised by specific bacterial populations, whose presence correlates with the radioelement concentrations/activities measured in these springs. This suggests that radioelements could partly explain the structuring of bacterial communities in these springs. In addition, several of these operational taxonomic units (OTUs) specific to Dourioux and Montagne, mainly affiliated to Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria, and Bacteroidetes, could be involved in the biogeochemistry of radionuclides through different mechanisms (biosorption, biomineralisation, bioaccumulation, and bioreduction), which would allow the development of other bacterial species sensitive to these metals/radioelements. In particular, the co-occurrence of sulphate and/or iron-reducing bacteria, capable of bioreducing uranium, with fermentative bacteria, releasing sources of organic carbons, reflects associations of bacteria with complementary functions that allow them to grow in this peculiar environment and maintain a high diversity in these extreme environments. This study has provided a better understanding of the structuring of bacterial communities exposed to ionising radiation for thousands of years in naturally radioactive environments.

Characteristics of Phosphate Sorption on Surface Sediments: A Study in Kendari Bay

Phosphate adsorption and desorption are significant processes that influence the presence of phosphate in aquatic ecosystems and regulate the concentration of phosphate at the water-sediment interface. This research aims to investigate the characteristics of phosphate adsorption and desorption in Kendari Bay sediments, study the relationship between adsorption capacity and sediment characteristics and its phosphorus fraction, and evaluate its potential contribution to the overlying water column. Physicochemical measurements of the water and sediments were performed in the sampling location and the laboratory. Two types of adsorption-desorption kinetics models and two types of isothermal adsorption models were used to estimate the adsorption rate and capacity of the surface sediments. Adsorption kinetics and desorption kinetics experiments produced pseudo-second-order kinetic model equations with regression coefficients (R2) of 0.865–0.936 and 0.886–0.947, respectively. The isothermal adsorption experiment follows the Langmuir equation model with R2 = 0.964. The maximum adsorption capacity (Qmax) value was 156.3–227.3 mg/kg, and the phosphate concentration value at zero equilibrium (EPC0) was 0.0026–0.0047 mgP/L. Notably, the EPC0 value was higher than the SRP concentration, indicating that the resuspension of phosphate ions from sediment into the water column could occur. Furthermore, there was a correlation between Qmax values with OP, Al-P, Fe-P, clay particles, and organic materials. Potential practical applications may include integrating sediment adsorption capacity data into ecosystem models to inform nutrient management strategies and promote sustainable coastal development in Kendari Bay and beyond.

Jenis-jenis Makrozoobentos yang Ditemukan di Batang Kuantan Kawasan Wisata Geopark Silokek Kabupaten Sijunjung

The Kuantan River in the Silokek Geopark Tourism Area, Sijunjung Regency, shows that the condition of the Kuantan River in the Silokek Geopark Tourism Area is a natural and potential tourism area, because the Kuantan River in the Silokek Geopark Tourism Area has become a tourist attraction due to its abundant natural wealth. However, gold mining has caused the Kuantan River water to be categorized as polluted, indicated by its turbidity. This study aims to determine the types of macrozoobenthos found in the Kuantan River within the Silokek Geopark Tourism Area, Sijunjung Regency. This research was conducted from August to December 2023. The research used a descriptive survey method, which included direct observation and sampling at the research site. The sampling technique used was purposive sampling, selecting three research stations. Sample identification was conducted at the Biology Education Laboratory, Universitas PGRI Sumatera Barat. Physicochemical water measurements were carried out at the Laboratory of Standardization and Industrial Services in Gadut, Padang, West Sumatra. The results of the research on the types of macrozoobenthos found in the Kuantan River within the Silokek Geopark Tourism Area, Sijunjung Regency, identified 10 species belonging to 2 classes: Gastropoda and Pelecypoda. Eight species of Gastropoda were found: Tarebia granifera, Thiara scabra, Brotia costula, Tryonia clathrata, Pleurocera acuta, Thiara scabra, Goniobasis livescens, Brotia sp., and 2 species of Pelecypoda: Corbicula manilensis and Pilsbryoconcha exilis.

River degradation impacts fish assemblages in&amp;nbsp;Kosovo’s Ibër basin

Fish sampling was conducted in 20 sites within the Ibër River and its tributaries in Kosovo (August 2023) collecting 23 taxa (1674 individuals) through a standardized electrofishing protocol. Relevant physico-chemical measurements and anthropogenic pressures were collected and analyzed with respect to the ichthyological data of the surveyed sites. The survey represents a rapid assessment procedure, limitations and prospects of the effort are described. Several attributes of the fish assemblages showed severe degradation, characterized by low population densities, low species diversity, minimal reproductive evidence and the absence of several sentinel species. Multiple anthropogenic pressures have severely modified the fish communities over a wide area; pollution, barriers to movement and hydroelectric dams stand out as important drivers of degradation. Only two fish species showed some level of tolerance to heavily polluted waters (Carassius gibellio, Rutilus rutilus). Low fish population densities were also correlated with various forms of hydromorphological degradation. Only Barbatula barbatula, Phoxinus sp. and Lepomis gibbosus had proportionately higher population densities in areas where impoundments and power-station dam hydropeaking were severe. In this regard, conservation actions are urgently needed.

Chlorella vulgaris-mediated bioremediation of food and beverage wastewater from industries in Mexico: Results and perspectives towards sustainability and circular economy

The food and beverage industries in Mexico generate substantial effluents, including nejayote, cheese-whey, and tequila vinasses, which pose significant environmental challenges due to their extreme physicochemical characteristics and excessive organic load. This study aimed to assess the potential of Chlorella vulgaris in bioremediating these complex wastewaters while also producing added-value compounds. A UV mutagenesis treatment (40 min) enhanced C. vulgaris adaptability to grow in the effluent conditions. Robust growth was observed in all three effluents, with nejayote identified as the optimal medium. Physicochemical measurements conducted pre- and post-cultivation revealed notable reductions of pollutants in nejayote, including complete removal of nitrogen and phosphates, and an 85 % reduction in COD. Tequila vinasses exhibited promise with a 66 % reduction in nitrogen and a 70 % reduction in COD, while cheese-whey showed a 17 % reduction in phosphates. Regarding valuable compounds, nejayote yielded the highest pigment (1.62 mg·g−1) and phenolic compound (3.67 mg·g−1) content, while tequila vinasses had the highest protein content (16.83 %). The main highlight of this study is that C. vulgaris successfully grew in 100 % of the three effluents (without additional water or nutrients), demonstrating its potential for sustainable bioremediation and added-value compound production. When grown in 100 % of the effluents, they become a sustainable option since they don't require an input of fresh water and therefore do not contribute to water scarcity. These findings offer a practical solution for addressing environmental challenges in the food and beverage industries within a circular economy framework.

Polyvinyl alcohol (PVA)-based films: insights from crosslinking and plasticizer incorporation

The properties of polyvinyl alcohol (PVA) films are intricately influenced by factors such as polymer structure, fabrication method, the addition of plasticizers and the molecular weight of monomers. This research, investigates the implication of PVA films using a solution casting method for crosslinking with boric acid (H3BO4), glycerol (C3H8O3) and citric acid (C6H8O7). This approach is compared with pure PVA films, establishing a valuable benchmark. For the experiments, tensile strength tests, physicochemical property measurements, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were conducted to gain insights into the microstructure, surface characteristics and mineral composition of the films. This comprehensive approach aims to enhance our understanding of the intricate relationship between PVA, plasticizers and crosslinking agents, providing valuable insights for applications across diverse industries, including, construction and biomedical fields. The overarching objective of this research is to revolutionize the construction industry by developing polymer films that serve as the foundation for self-healing materials, fostering durability and innovation. The experiments revealed a significant influence of crosslinking agents on the properties of PVA films as measured.

Water Quality from Natural Sources for Sustainable Agricultural Development Strategies: Galapagos, Ecuador

Water is an essential element for agricultural sustainability. In volcanic islands, freshwater sources are limited, challenging the local farming water supply. Rainfall dependence in the Galapagos Islands limits continuous agriculture, and despite using natural water sources, their irrigation quality is little known. This study aimed to carry out a control–diagnosis of irrigation water quality of the natural sources of the four agrarian islands of the Galapagos, considering water quality parameters for the proposal of sustainability strategies in the water and agricultural context. The workflow included (i) freshwater supply situation diagnosis, (ii) physicochemical parameters measurement and hydrochemical characterisation, and (iii) irrigation analysis and sustainability strategies configuration. Results indicated that of the 34 sources analysed, 55.88% are suitable for irrigation and are located in San Cristobal and Santa Cruz. The remaining 44.12% showed problems with parameters such as faecal coliforms, salinity, metals, carbonates, BOD5, and COD above the national permitted limits. Six strategies for water and agricultural sustainability are proposed, including periodic water monitoring, academy–government–community projects, community water board creation, water sowing and harvesting systems, effective management of effluent, and agricultural strengthening. The study guides comprehensive hydric management initiatives to benefit agrarian development and food security, aligning with SDGs 2 and 6.