Physicochemical Properties Of Water Research Articles

Spatiotemporal discrepancies and risk assessment of toxic heavy metals in surface water of Shitalakhya River around Narayanganj port in Bangladesh

The urban rivers of developing countries like Bangladesh have been severely affected by toxic heavy metal pollution, posing serious ecological and human health risks. This study aimed to investigate the concentrations, spatiotemporal discrepancies, and associated risks of five alarming toxic metals (Pb, Cd, Cr, Cu and Mn) in the surface water of urban Shitalakhya River around Narayanganj port, one of the biggest and most important river ports in Bangladesh. Water samples were collected for three prevailing seasons i.e., pre-monsoon, monsoon, and post-monsoon from five selected sites. Physicochemical properties (color, odor, temperature, DO, pH, EC and TDS) of river water were also assessed, while heavy metal pollution index (HPI), heavy metal evaluation index (HEI) and degree of contamination (CD) were calculated to evaluate the risks associated with toxic metal pollution in river water. The findings revealed that several physicochemical parameters, especially DO, EC and TDS, were not within the standards. The hierarchy of mean heavy metal concentrations in Shitalakhya River water was found as Mn>Cr>Cu>Cd>Pb during pre-monsoon, Mn>Cu>Cr>Cd>Pb during monsoon, and Mn>Cr>Cu>Pb>Cd during post-monsoon season. The metal concentrations were found to be higher in pre-monsoon and post-monsoon seasons, whereas the concentrations of all the heavy metals excluding Mn were within the standards recommended for domestic use, surface water, fisheries and irrigation purposes. The comparative analysis exhibited that the water quality of Shitalakhya River is deteriorating day by day at an alarming rate. HPI showed a critical pollution index value (drinking) for all three seasons, whereas HEI revealed low heavy metal contamination for all sampling stations. The values of CD indicated a high level of contamination in pre-monsoon and post-monsoon but monsoon season. The results confirmed the spatiotemporal discrepancies in toxic metal concentrations and associated ecological and human health risks, possibly resulting from the hydrological and anthropogenic interventions not only associated with port activities. Hence, urgent collective effort and proper monitoring are of utmost importance to safeguard the public health and this urban riverine ecosystem. Int. J. Agril. Res. Innov. Tech. 14(2): 74-84, December 2024

Effect of Vegetable Oil Adjuvant on Wetting, Drift, and Deposition of Pesticide Droplets from UAV Sprayers on Litchi Leaves

The spatial transportation of pesticide spray droplets and their deposition and retention on plant leaf surfaces are critical factors contributing to pesticide loss. Adding adjuvants to pesticide solutions to improve their wettability and deposition behavior can enhance the targeted deposition efficiency of pesticides sprayed by unmanned aerial vehicle (UAV) sprayers. In this study, Maifei(MF), a prevalent vegetable oil adjuvant, was selected to analyze its effects on the physicochemical properties of water and 10% difenoconazole water-dispersible granules (D) and the wetting performance of droplets on litchi leaves. The changes in the drift and deposition of the spray solutions with or without MF were tested using a UAV sprayer, DJI T40. The results indicated that the addition of MF to water or D significantly decreased the surface tension (by 58.33% and 23.10%, respectively), wetting time (by 97.81% and 90.95%, respectively), and contact angle (by 40.95% to 70.75% for the adaxial and abaxial surfaces of litchi leaves), achieving the best effects at a 1% MF addition. Moreover, during the drift test, the addition of 1% MF to the solutions significantly reduced the cumulative drift rate (CDR) (by 48.10%). Finally, owing to the weakened spray drift risk and improved wettability of the droplets on litchi leaves with a 1% MF addition, the droplet deposition and penetration in the litchi canopy significantly improved, demonstrating an increased droplet density of 38.17% for the middle layers of the litchi and 15.75% for the lower layers, corresponding to increased coverage by 59.49% and 12.78%, respectively. Hence, MF can improve the interfacial properties of the spray solution on litchi leaves, reduce the drift risk, and promote deposition, thereby facilitating the efficient transfer and deposition of pesticide droplets from UAV sprayers.

Water Physicochemical Properties Influence the Production, Nutritional Composition, and Antioxidant Activity of Gracilaria tenuistipitata From the Northern Bay of Bengal, Bangladesh

This study investigates the influence of water physicochemical properties on the growth, production, nutritional composition, and antioxidant properties of Gracilaria tenuistipitata, cultivated at two different sites (Gangamati and Hazipur) along the northern Bay of Bengal, Bangladesh. The water quality parameters were monitored weekly. Results revealed that the Gangamati site is characterized by significantly higher (p < 0.05) salinity (14.75 ± 4.89 ppt), transparency (60.50 ± 9.57 cm), and total dissolved solids (6154.90 ± 1492.50 mg/L) compared to the Hazipur site. The Gangamati site significantly (p < 0.05) outperformed the Hazipur site in terms of daily growth rate and production. Furthermore, proximate composition analysis indicated significantly higher (p < 0.05) protein (25.06 ± 0.90% DW), lipid (1.22 ± 0.05% DW), fiber (7.03 ± 0.76% DW), and carbohydrate (38.41 ± 0.80% DW) contents in seaweed from the Gangamati site. The mineral content of G. tenuistipitata was also influenced by the culture site significantly (p < 0.05). Amino acid analysis demonstrated superior protein quality in Gangamati seaweed, with significantly higher levels of essential (77.286 ± 0.06 mg/g) and nonessential (95.243 ± 0.07 mg/g) amino acids than the Hazipur site. The fatty acid profiles varied significantly between the two sites, with seaweed from the Gangamati site exhibiting higher levels of unsaturated fatty acids (41.27 ± 0.05%) compared to Hazipur, indicating superior nutritional lipid quality indices. Bioactive compounds were significantly higher (p < 0.05) in Gangamati seaweed, along with higher antioxidant activity. Overall, these results indicate that the Gangamati estuary provides a better environment for the cultivation of G. tenuistipitata, resulting in seaweed with superior nutritional and bioactive properties.

Evaluation of water hardness treatment methods using sodium hydroxide and their impact on water quality

Hard water is an environmental and technical challenge caused by high concentrations of calcium (Ca²⁺) and magnesium (Mg²⁺) ions, leading to scale formation that affects the efficiency of household and industrial appliances and increases maintenance and treatment costs. Additionally, hard water can pose health risks and reduce its quality for daily use. This study aims to evaluate the effectiveness of different doses of sodium hydroxide (NaOH) in treating water hardness and improving water quality by reducing total hardness (TH) and adjusting the physicochemical properties of water. Three main dosages were tested: the first dosage (5 g/L of NaOH), which assessed the basic effectiveness of sodium hydroxide; the second dosage (2.5 g/L of NaOH and 2.5 g/L of Na₂CO₃ with HCl and acid), aimed at balancing hardness reduction with mineral retention; and the optimized dosages (10, 20, and 30 mg/L of NaOH), which proved to be the most effective and balanced. The optimized doses successfully reduced total hardness to levels compliant with Algerian standards while maintaining calcium and magnesium concentrations within acceptable ranges. Furthermore, electrical conductivity (EC) remained within safe limits without significant increases, ensuring the water did not become oversaturated with dissolved salts. The slight increase in sodium (Na⁺) concentration also remained within permissible levels, enhancing the water's suitability for drinking and other uses. Based on these results, the optimized NaOH dosages are the optimal solution for water hardness treatment, achieving a balance between reducing hardness and ensuring water quality in compliance with local standards.

Psycho-Chemical Characteristic of Groundwater Quality in Hard Rock and Alluvium Aquifers in Pangkalpinang City, Bangka Belitung Islands Province

Abstract The people of Pangkalpinang City generally use water sourced from groundwater and from the reservoirs of former tin mining excavations commonly called “Kolong.” However, the quality of the Kolong water used has a pH that tends to be acidic, while the groundwater quality has yet to be detected. In line with these problems, this study aims to analyze groundwater quality based on groundwater’s Psycho-Chemical properties associated with the lithology distribution in the study location. There are 3 rock units in the research location: the phyllite rock unit, classified as hard rock, sandstone unit, and alluvium unit. The results obtained in the comparison of Psycho-Chemical parameters of groundwater based on lithology spread over 98 observation wells are in the phyllite rock unit; there are 9 observation wells with pH 4.67-6.26; EC 72-291 μS/cm; and TDS 38-142 mg/L. The sandstone rock unit has 57 observation wells with pH 4.36-8.41, EC 36-5394 μS/cm, and TDS 17-2732 mg/L. The alluvium unit has 32 observation wells with pH 4.68-8.54, EC 32-12333 μS/cm, and TDS 16-6167 mg/L. A comparison of groundwater quality characteristics based on the physico-chemical properties of water with the distribution of lithology illustrates that the quality of groundwater in the phyllite rock unit has a low pH (acidic), so it must get treatment first to be suitable for use by the community as clean water. At the same time, the results of the analysis of groundwater Psycho-Chemical parameters for EC and TDS values in sandstone and alluvium units are in the Slightly Brackish and Brackish categories, where this can be caused by several factors, such as the possibility of contamination by salt water (geogenic) or contamination by human activities (anthropogenic) so that further research needs to be done to find out the source of groundwater pollution at the research site.

Assessment of Physicochemical Properties of Water and Public Perceptions of Water Quality in Tasik Chini, Pahang, Malaysia

The study was conducted to evaluate the physicochemical parameters of water and assess the public perception of the water quality status in the Tasik Chini watershed based on a community survey. The water sample was analyzed based on standard methods and categorized according to WQI (Water Quality Index). Multivariate statistical analysis was adopted to find spatial variations in water quality, determining the pollution level and sources of contamination. The study results were compared with NWQS (National Water Quality Standard for Malaysia). The results showed that the value of dissolved oxygen (DO) was low (4.68 mg.L-1), while the level of biological oxygen demand (BOD), chemical oxygen demand (COD), and total dissolved solids (TDS) was found to be high, 2.92 mg.L-1, 26.10 mg.L-1 and 22.93 mg.L-1 respectively. High turbidity was recorded in a mining area in the rainy season (35.76 NTU). The DOE-WQI value categorized the lake under class II and class III. The Principal Component Analysis (PCA) revealed that the major sources of contamination were due to anthropogenic activities, especially settlement, mining, agriculture, and illegal activities. Overall, Tasik Chini’s water quality status was classified as slightly polluted to highly polluted based on hierarchical cluster analysis (CA) results. The survey showed that 55% of the local community reported that the water quality was poor. The knowledge and attitude level of the local people was medium category, while community practice was low. The Pearson correlation coefficient test showed a strong significant relationship at 0.01 level between knowledge and attitude and knowledge and practices. The scientific findings with public perceptions might be useful for policymakers and the general public to improve the management system for a desirable future.

Insights on bacteria inactivation in water by cold plasma: Effect of water matrix and pulsed plasmas waveform on physicochemical water properties, species formation and inactivation efficiency of Escherichia coli

This study investigates the inactivation of Escherichia coli (E. coli) using pulsed dielectric barrier discharges (DBDs) powered by high-voltage nanosecond and/or microsecond pulses to establish optimal operational conditions. The effects of pulse voltage waveform and water matrix (distilled vs. tap water) were evaluated in terms of inactivation efficiency and energy consumption, along with the generation of reactive oxygen and nitrogen species (RONS). Complete E. coli inactivation (9-log CFU/ml) in distilled water was achieved within 20 min of nanopulsed-DBD treatment, coinciding with rapid acidification, while in tap water, 90 min was required for complete inactivation. Interestingly, at treatment times with similar pH levels between water types, E. coli inactivation was more effective in tap water. Ozone concentrations showed the most significant difference, being ∼6 times higher in distilled water (10.3 mg/L) than in tap water (1.7 mg/L). Although distilled and tap water had similar concentrations of short- and long-lived plasma species, the differing inactivation efficiencies indicate a synergistic effect between pH reduction and reactive species in impairing E. coli functionality. Micropulsed-DBD led to increased concentration of plasma species, faster acidification and inactivation in tap water (complete inactivation within 8 min), but at significantly higher electrical energy per order (56.9 kWh/m3 compared to 17.4 kWh/m3 for nanopulsed-DBD). The lowest energy per order was recorded for nanopulsed-DBD in distilled water, at 3.8 kWh/m³, highlighting pulsed-DBD plasma as a safe and energy-efficient method for water disinfection. This study offers valuable insights into using an innovative, sustainable plasma-based approach for bacterial inactivation.

Changes in microbial communities across the whole A2/O wastewater treatment process and their drivers—Reduced community diversity but increased proportion of certain pathogens

Microorganisms play a crucial role in pollutant removal and water quality stabilizing. However, limited research exists on the microbial variability and the factors driving it at different stages of wastewater treatment. In this study, the physicochemical properties of water and the composition of bacterial communities were thoroughly investigated across the entire A2/O wastewater treatment process, encompassing 3 stages (12 steps). The results revealed a significant reduction in alpha diversity, whereas the beta diversity remained largely unchanged across stages. Alpha diversity was primarily influenced by dissolved oxygen (DO) and pH, with DO having the most notable influence, while beta diversity was mainly constrained by nutrient conditions such as COD, BOD5, NH4-N, TN, and TP. Additionally, analyses of relative abundance, LEfSe, variance, and functional prediction indicated a significant increase in the relative abundance of certain pathogenic bacteria (e.g., Legionella, Leptospira), exhibiting different removal characteristics compared to Escherichia coli across various treatment steps. Even after UV disinfection, these pathogens persist, highlighting a potential pathogenic risk, which deserves more attention. In addition, this study helps explore the relatively under-researched area of microbial variability at different stages (steps) of wastewater treatment, especially in terms of how microbial communities respond to operational processes and environmental conditions. This will offer valuable guidance for addressing water treatment safety challenges encountered in real-world processes.

Impact of water physicochemical properties on the survival of Oncomelania hupensis snails, the intermediate host of Schistosoma japonicum

BackgroundSchistosoma japonicum, the causative agent of schistosomiasis, heavily relies on its single intermediate host, the Oncomelania hupensis snail, for its life cycle. Controlling these snails effectively plays a pivotal role in curbing the transmission and prevalence of this disease. While prior research has extensively investigated the impact of environmental factors such as temperature and vegetation on snail survival, growth, and reproduction, the contribution of water physicochemical properties has been notably underexplored. This study presents laboratory experiments designed to comprehensively explore the influence of water physicochemical properties on snail survival, offering valuable insights into environmental factors for more precise predictions of snail distribution.MethodsWe meticulously conducted laboratory snail survival experiments using water from different sources (river water/tap water), and employed a statistical approach amalgamating principal component analysis with Cox regression to preliminarily investigate the effects of different water physicochemical properties on the survival of snails.ResultsOur analysis indicates that after a 6-month laboratory snail survival experiment, the survival rate in the tap water group was significantly higher than that in the river water group for infected snails (χ2 = 7.74, p = 0.005), while the difference in survival rates for non-infected snails was not statistically significant (χ2 = 0.61, p = 0.434). The Principal Component-Cox regression analysis revealed that in the infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, while phosphate and total nitrogen were risk factors. In the non-infected snail group, total phosphorus, pH value, five-day biochemical oxygen demand, conductivity, and nitrite were protective factors for snail survival, and total nitrogen, ammonia nitrogen, phosphate, and nitrate were risk factors.ConclusionsThis study underscores the substantial impact of water quality’s physicochemical properties on snail survival. The effects of water quality on snails are complex, and maintaining an appropriate level of organic matter content and controlling the pH value at a weak alkalescency level prove beneficial for snail survival. These findings hold significant promise for advancing our understanding of snail-borne diseases and optimizing control strategies.

The functions and factors governing fungal communities and diversity in agricultural waters: insights into the ecosystem services aquatic mycobiota provide.

Fungi are essential to the aquatic food web, nutrient cycling, energy flow, and ecosystem regulation. Fungal community structures in water can be influenced by adjacent terrestrial environments, which drive and control some ecosystem services they provide. However, the roles of freshwater fungal communities remain underexplored compared to bacterial communities in this context. We assessed the impact of anthropological and environmental factors on freshwater mycobiota in an agriculturally dominated water basin in eastern Ontario, Canada. We undertook bi-weekly surface water sampling from 2016 to 2021 and conducted fungal internal transcribed spacer 2 (ITS2) metabarcoding on the samples, complemented by ancillary data, including water physicochemical properties, upstream land use, hydrology, and weather conditions. Our study yielded 6,571 OTUs from 503 water samples, spanning 15 fungal phyla, dominated by Ascomycota, Basidiomycota, and Chytridiomycota. Agricultural land use was associated with decreased mycobiota alpha diversity and distinct fungal communities were observed at agricultural drainage ditch and mixed-land use sites compared to a forested site that had minimal anthropogenic activities in catchment. Notably, river discharge emerged as a predominant influencer of both community diversity and composition, likely amplified by precipitation-induced erosion and drainage from adjacent terrestrial environments. Water physicochemical properties, including stream fungicide levels, explained a small proportion of the variation in mycobiota communities, underscoring the significance of unmeasured factors, alongside stochastic community assembly processes. Nevertheless, stream mycobiota demonstrated functional resilience for critical ecological processes under different environmental conditions. Altogether, these results highlight the complex interplay of factors influencing the freshwater mycobiota, which is essential for elevated understanding of the ecosystem services these fungi provide.

Physico-chemical properties of borehole water and heavy metal contamination in soil near an open dumpsite in Giwo District, Bauchi, Nigeria.

Physico-chemical properties of borehole water and heavy metal contamination in soil near an open dumpsite in Giwo District, Bauchi, Nigeria.

Variations in Water Quality Index and Physicochemical Properties of Surface Water and Bottom Sediments of Selected Coastal Beaches of Niger Delta, Southern Nigeria

Variations in Water Quality Index and Physicochemical Properties of Surface Water and Bottom Sediments of Selected Coastal Beaches of Niger Delta, Southern Nigeria

Hydrographic and hydrochemical characteristics of selected groundwater outflows in desert and semi-desert areas

The presence of natural groundwater outflows depends on many factors, such as lithology, geological structure, and climate. Areas with particularly poor crenological recognition are arid and semi-arid regions, primarily due to rarity of groundwater outflows in these locations. The article presents the hydrographic and hydrochemical characteristics of selected groundwater outflows in arid and semi-arid areas. In addition to hydrographic mapping, basic physical parameters of water were measured in selected springs, such as temperature (T, °C), electrolytic conductivity (EC, μS∙cm–1), and reaction (pH, –). Laboratory analyses determined the major cations and anions in water: Ca2+, Mg2+, Na+, K+, NH4+, SO42−, Cl−, NO3−, Br−, PO43−,. The analyses were performed using an ion chromatograph Metrohm 850 Professional IC. Twenty-four natural groundwater outflows in South America, Africa, and Asia were selected for research. It was found that the vast majority of outflows are transit sources. Their supply area may be far from discharge points. The supply source is rainwater or meltwater from high mountain massifs. Other types of outflow are springs of alluvial fans and braided rivers. They are fed by waters from glacial rivers, which infiltrate alluvial deposits and flow back to the surface. Hydrochemical analysis has shown that the physicochemical properties of water in dry areas vary significantly. Still in the hydrochemical type, there is a predominance of sulphate, chloride, and sodium ions. This distinguishes the spring waters from these areas in temperate latitudes, which are dominated by bicarbonate and calcium ions.

Development and study of a selective isolation technology based on gum arabic-acrylamide taking into account the physicochemical properties of formation waters

The presented article discusses the preparation and investigation of a composition based on the natural polymer gum arabic and the vinyl monomer acrylamide, which undergoes chemical transformation under downhole conditions to form a gel. N,N-methylenebisacrylamide and FeCl3 salt were used as cross-linking agents during the process. The prepared homogeneous solution had a low density and a pH range of 5.86 to 6.37. The composition is viscoelastic, exhibiting characteristics typical of non-Newtonian fluids and demonstrating the Weissenberg effect. It was determined that the boiling point of the composition is 103.7 oC, and the freezing point is -4.5 oC. Depending on the concentration of the components, the density ranged from 959 to 967 kg/m³, with gel formation occurring within 43–397 minutes at temperatures between 25–75 oC. At 50 oC, the gelation time ranged from 151 to 183 minutes, depending on the reagent concentrations, which is sufficient for well injection. During the experiments, the swelling kinetics of the biopolymer-based gel in waters with different hardness and mineral content were studied. The swelling rate of the gels increased rapidly within 3–4 hours, with all water samples showing up to a 300 % increase, meaning the gels absorbed 3–4 times their weight in water or hydrates. It was shown that the swelling of the biopolymer-based gel increased sharply over 1–30 hours and continued to stabilize over the next 160 hours, reaching up to 650 %. The boiling temperature of the composition corresponding to the optimal formulation is characterized by Raoul’s law. It has been determined that the boiling temperature of the composition prepared is 103.7 oC, while the freezing temperature is -4.5 oC. The density of the biopolymer-based mixture was determined using a pycnometer at room temperature, and it ranged from 959 to 967 kg/m³ depending on the dose of components. Prepared composition is in distilled water, its electrical conductivity is very weak and even approaches that of pure water. The electrical conductivity of the biopolymer-based composition prepared in distilled and simple water ranged from 0.04 to 0.07 and 1.6 to 1.7 μS/cm, respectively, depending on the concentration of the reagents in the composition. The prepared biopolymer-based composition can be used as a plugging material for the isolation of undesirable or formation waters in the oil industry.

Physicochemical Properties of Water in Contact with Nanobubbles Generated by CO2‐Hydrate Dissociation: An Investigation from Experiment and Molecular‐Dynamics Simulation

AbstractThe study investigates CO2‐nanobubbles (NBs) generated from gas‐hydrate dissociation, exploring their impact on the physicochemical properties of liquid water. Raman spectroscopy evidenced a slight increase in the Raman‐band intensity, suggesting enhanced total hydration‐layer water‐dipole moment and polarity without affecting water molecule structuring. Furthermore, an overall decreasing trend for the zeta potential of NB solution can be observed due to the strong electron affinity on the surface of CO2 bulk NBs, probably caused by a negative charge accumulation. These findings are in good qualitative accord with molecular‐dynamics (MD) simulation results, wherein water can induce a small dipole moment of about 0.16 D for CO2 NBs, thereby increasing the polarity of the system. Due to the interaction between water molecules, the Coulombic or electrostatic forces increase in the presence of NBs compared to pure water, which can reflect the increase in the dipole moment of water molecules in the presence of NBs. The presence of NBs strengthens the local hydrogen‐bond network, leading to higher‐frequency vibrations. Additionally, NBs amplify the intrinsic electric field of the aqueous solution, causing the gas‐water interface to exhibit negatively charged characteristics, dependent on NB size. Molecular simulations agree qualitatively with experiments, emphasizing their utility in studying NB evolution in water.

Key Issues and Challenges in Establishing Regionally Differentiated Water Quality Standard in China

The goal of environmental management in China is transitioning from pollution control to the improvement of ecological quality. The establishment of regional differential water quality standards can better adapt to the ecological characteristics and development needs of different regions. Given the shortcomings of current water quality standards and the needs of technological development, this study analyzed the causes and influencing factors of regional differences in water quality standards and summarized China's regional variations in areas such as the characteristics of receiving water bodies, social attributes, climate conditions, physicochemical properties of water, and aquatic biotic populations. It also examined the impact of regional characteristics on the assessment of biological toxicity. Based on these analyses, the study identified key scientific questions that may arise in the development of regional differential water quality standards in China and outlined future critical research directions in this field. These directions include developing theories and methods for determining the effluent dilution coefficient, establishing methods for identifying regional key water quality indicators and assessing their impact on water quality standards, determining regional characteristic species and their influence on water quality standards, and formulating theories and methods for categorizing different regions across the country. The aim of the study was to provide a reference for the scientific establishment of water quality standards in China.

Taxonomy and Distribution of Benthic Foraminiferans in the Selected Group Islands of Gulf of Mannar Marine Biosphere Reserve

The present work deals with the taxonomy and distribution of benthic foraminifera from Gulf of Mannar Marine Biosphere Reserve (GoMBR), South east Coast of India during 2020 – 2023. Sediment samples were collected from Mandapam, Keezhakarai and Vembar group of Islands through standard methodology, A total of 36 species belonging to 20 genera, 16 families and 4 orders. A holistic approach regarding soil texture and physico-chemical properties of soil and water shed more light on the diversity and distribution of foraminifera in GoMBR.

Characterization of Different Clay Mines and Preparation and Preservation Properties for Lateolabrax japonicas Fillets Unidirectional Water‐Conducting Preservation Pads Loading Clay Mines

ABSTRACTIn order to inhibit the growth and reproduction of microorganisms in the exudate of fresh aquatic products during storage. Absorbent paper, absorbent cotton and nylon mesh were used as the substrates, three types of clay minerals (diatomite, columnar diatomite and bentonite) were used as the water absorbing materials and a new type of unidirectional water‐conducting preservation pads was prepared. The physicochemical properties of water absorbing materials and preservation properties of pads for Lateolabrax japonicas fillets were measured. The results show that all three kinds of clay have good water absorption properties, and bentonite exhibits the highest water retention properties because of metal oxide. After absorbing water, the surface holes of diatomite and columnar diatomite particles are blocked, while the volume of bentonite particles increases. Bentonite absorbs water slowly but retains water best and can absorb 10.31 times its own mass of water. Preservation study shows that water absorption preservation pads can effectively absorb the exudate of fish fillets and slow down the deterioration of fish fillet quality. Bentonite preservation pad shows the best effective and extends the shelf life of L. japonicas fillets from 6 to 9.3 days. This research can provide the technical support for the application of preservation pads carrying clay minerals in the field of fresh aquatic products.

ИЗУЧЕНИЕ ФИЗИКО-ХИМИЧЕСКИХ СВОЙСТВ «ЛЕГКОЙ» ВОДЫ И ЕГО ВЛИЯНИЕ НА РОСТ И РАЗВИТИЕ РАСТЕНИЙ

The article is devoted to the study of the physico-chemical properties of light water and its effect on plant growth and development. The author focuses on the fact that water does not occur in nature in its pure form, since it always contains various chemical elements. The types of water are considered: chemically and physically bound, as well as free water. Special attention is paid to the isotopic composition of water, including heavy water, and its physical characteristics such as density, boiling point and melting point. An experiment on the effect of light water depleted with deuterium on the growth of indoor roses is described. The study showed that plants watered with light water develop better compared to control groups watered with ordinary water. The author provides data on the results of plant growth for 12 weeks, which confirms the unique properties of light water, which helps to improve the condition of plants. In addition, an analysis of the chemical composition of drinking water and a phytochemical analysis of the content of flavonoids in plants watered with various types of water is provided. In conclusion, it is emphasized that light water has significant advantages over conventional water, which makes it promising for use in agriculture.

Ensuring the normalization of the aero-ionic regime in production areas by means of ultrasonic air ionization

The results of studies on the normalization of the aeroionic regime in rooms under ultrasonic ionization of humidified air are presented. The increase in the concentration of negative aeroions under these conditions by the combined effect of the balloelectric effect and ultrasonic cavitation is substantiated. It has been established that when distilled water is used as a source of air ions under the action of a 10 W ultrasonic generator at a distance of 0.5 m, the concentration of negative air ions increases almost sixfold. At the same time, due to the joint effect of ultrasonic cavitation in the surface layer of water and the balloelectric effect, no generation of ozone and nitrogen oxides is caused. It is proved that with a decrease in the degree of water mineralization, the concentrations of negative and positive aeroions increase due to changes in the physicochemical properties of water and the resulting mechanochemical phenomena. The mechanism of formation of air ions in the air of industrial premises under the combined action of the balloelectric effect and ultrasound is proposed. It is substantiated that the quality of the air ionic composition of industrial premises air improves at a temperature of demineralized water of 20-25 °C and a directed air flow of 6 m/s towards the working area with the combined effect of ultrasound and balloelectric effect, which contributes to the improvement of sanitary and hygienic working conditions. The structure of an automated system for controlling the aeroionic regime of the working area of industrial premises with artificial ionization of humidified air using an aeroion generator and a ventilation system is proposed. This will allow monitoring and processing of information on technological, electrical and microclimatic parameters, adjusting, coordinating and jointly controlling the ventilation system devices and the ultrasonic generator of air ions.