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Many soils and other porous media exhibit dual- or multi-porosity type features. In a previous study (Seki et al., 2022) we presented multimodal water retention and closed-form hydraulic conductivity equations for such media. The objective of this study is to show that the proposed equations are practically useful. Specifically, dual-BC (Brooks and Corey)-CH (common head) (DBC), dual-VG (van Genuchten)-CH (DVC), and KO (Kosugi)1BC2-CH (KBC) models were evaluated for a broad range of soil types. The three models showed good agreement with measured water retention and hydraulic conductivity data over a wide range of pressure heads. Results were obtained by first optimizing water retention parameters and then optimizing the saturated hydraulic conductivity (K s ) and two parameters (p, q) or (p, r) in the general hydraulic conductivity equation. Although conventionally the tortuosity factor p is optimized and (q, r) fixed, sensitivity analyses showed that optimization of two parameters (p + r, qr) is required for the multimodal models. For 20 soils from the UNSODA database, the average R 2 for log (hydraulic conductivity) was highest (0.985) for the KBC model with r = 1 and optimization of (K s , p, q). This result was almost equivalent (0.973) to the DVC model with q = 1 and optimization of (K s , p, r); both were higher than R 2 for the widely used Peters model (0.956) when optimizing (K s , p, a, ω). The proposed equations are useful for practical applications while mathematically being simple and consistent.

This study assessed the applicability of chitin nanocrystals prepared by 2, 2, 6, 6-Tetramethyl-1-Piperidine-1-oxyl radical (TEMPO)-mediated oxidation in traditional papermaking coating color systems. The α-chitin nanocrystals (CTNCs) with different carboxyl content, size, and morphology were prepared from crab shells by alkali pretreatment and TEMPO-mediated oxidation in the water at pH 10, and then the ratio of CTNCs to latex was applied to traditional coating color system to replace part of latex. The results showed that when the amount of NaClO added as co-oxidant in the oxidation was 15.0 mmol/g of chitin, the carboxyl content of alkali-pretreated CTNCs was up to 0.76 mmol/g. The amount of carboxyl groups presented a linear relation with the degree of individualization of nanocrystals and dispersion. When the ratio of latex to CTNCs was 90꞉10, the water retention value of the coating was 92% lower than that of the pure latex system, and the rheological property was better. The relationship between the addition amount of CTNCs and the surface strength and the coverage of coating layers were also studied, and results showed that when the ratio of latex to CTNCs was 95꞉5, the surface strength was the highest of 1.45 m/s, and the coverage of coating layers rate reached the highest of 78%.

Compacted soils used as formation layers of railways and roads continuously undergo water content and suction changes due to seasonal variations. Such variations, together with the impact of cyclic traffic-induced loads, can alter the hydro-mechanical behaviour of the soil, which in turn affects the performance of the superstructure. This study investigates the impact of hydraulic cycles on the coupled water retention and cyclic response of a compacted soil. Suction-monitored cyclic triaxial tests were performed on a compacted clayey sand. The cyclic response of the soil obtained after applying drying and wetting paths was different to that obtained immediately after compaction. The results showed that both suction and degree of saturation are required to interpret the cyclic behaviour. A new approach was developed using (a) a hysteretic water retention model to predict suction variations during cyclic loading and (b) Bishop's stress together with a bonding parameter to predict accumulated permanent strain and resilient modulus. The proposed formulations were able to predict the water retention behaviour, accumulated permanent strains and resilient modulus well, indicating the potential capability of using the fundamentals of unsaturated soils for predicting the effects of drying and wetting cycles on the coupled soil water retention and cyclic response.

Bentonite is low resistance water retaining conductive clayey material often used as grounding enhancement material, particularly in a troubled environment. Due to its unique property, bentonite retains water and dissipate unwanted electrical current to ground. However, bentonite's water retention capacity would inevitably induce corrosion to the grounding electrode and may jeopardize the grounding system's performance in the long run. This study presents bentonite properties on copper electrodes' corrosion behavior. In this study, copper corrosion behavior buried in Andrassy bentonite specimens was investigated under varying relative humidity conditions using the vapor equilibrium technique. The corrosion rate was calculated at equilibrium, and FESEM later characterized the corroded surfaces. The copper corrosion rate in Andrassy bentonite was found to be between 2.2 and 2.8 × 10-3 mm/year. Test results showed that more water might not necessarily induce and expedite copper corrosion. However, it was noted that copper corrosion was somewhat limited under extremely dry conditions and very wet conditions. On the other hand, RH = 75% was the optimum copper corrosion condition to occur. It is believed that the corrosion of copper specimen may be influenced by other complex mechanism presence of such as chemicals species and microbes contained within the bentonite and surrounding environment.

The performance of open-cathode fuel cell systems is limited by deficient humidification and thermal gradients within the individual cells. This work investigates ionomer design strategies to passively control hydration and thereby overcome the inherent performance limitations of such systems. An experimentally validated three-dimensional computational model is used to analyze the effect of a critical ionomer property, namely the water sorption/desorption rate constant at three levels, for cell performance and spatially resolved temperature and water activity. The current density at 0.6 V is found to increase remarkably by 130% by reducing the water sorption/desorption rate constant from 10 s−1 to 0.1 s−1 under ambient air at 40 °C and 40% relative humidity. This is accomplished through enhanced water retention and membrane hydration at elevated temperature.

Since unsaturated soil conditions are normally experienced above the groundwater table, most treated or stabilised soils for roadworks, earth dams’ embankments, landfill sites, hydraulic barriers etc. could be regarded as existing in this region. The soil–water characteristic (or retention) curve (SWCC) is a useful conceptual tool by which an evaluation of unsaturated soil's property functions and corresponding macro-scale behaviour (strength, volume change, hydraulic conductivity, fluid flow, diffusivity, etc.) can be carried out. Hence, an examination of some of the various factors that could affect the hydraulic or water retention property of the stabilised soil is very vital both for laboratory studies and field practice. However, a thorough assessment of the water retention behaviour of stabilised soils can be understandably limited sometimes. This could be partly due to some of the perculiar conditions associated with soil preparation methods, soil type, soil-stabiliser mix proportion used, curing conditions, method of compaction, durability assessment modalities and other logistical issues surrounding either laboratory instrumentation or in-situ application. This article presents a critical and comprehensive review of these factors on the stabilised soil’s water retention behaviour and also provides a systematic understanding of the mechanisms of stabilisation occurring at the micro- and macro-mechanical levels. Recommendations are also made to stimulate further discussions on the synthesis of SWCC of stabilised soils vis-a-vis factors influencing them with possible interpreted engineering behaviours such as shear strength and soil consolidation.

Water retention procedures by sealing are often suggested during the laboratory preparation of the calcium oxalate protective film. In fact, water retention by sealing is impractical in application and is not always necessary under certain circumstances. In this paper, calcium oxalate was prepared without water retention in a humid environment and the protective performance was investigated by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), acid resistance, porosity, capillary water absorption, colour difference and surface strength. The results show that the calcium oxalate film with good protective performance can be successfully prepared without water retention in the environment with a relative humidity more than 76%. This is meaningful for the protective treatment of the historic stones in high humidity.

Context Biochar and pumice have potential to improve soil water retention and mitigate salinity. However, little is known about their effect on salt transport in sandy soils. Aims We investigated the influence of the porosity and pore size distribution of soil amendments with pumice and biochar on the mobile water content of a New Zealand sandy soil. Methods Pumice and biochar (1.5-cm, 3-cm and 6-cm in diameter, Ø) were characterised using scanning electron microscope technology. The fraction of mobile water present in these amendments, previously added to a sandy soil at different application rates and particle sizes, was determined using a tracer (Na+) technique. Key results (1) Pumice exhibited a wider pore-size span than biochar; and (2) both materials had a predominance of pores with Ø

Considerando-se que os substratos apresentam constituições físico-químicas diversas e que a liberação de íons do substrato, ou a adição de fertilizantes, eleva a condutividade elétrica da solução, este trabalho teve como objetivo avaliar a retenção de água em substratos com hidrogel com presença e ausência de adubação. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 3 x 2, com quatro repetições. Os fatores constituíram de quatro tipos de substratos (casca de pinus compostada, pó-de-coco (fibra do mesocarpo triturada), turfa de Sphagnum e substrato comercial (à base de turfa de Sphagnum, vermiculita expandida, casca de arroz torrefada, calcário dolomítico e gesso agrícola), três formas de aplicação do produto hidrogel (sem aplicação, com aplicação sem pré-hidratação e com aplicação após hidratação) e duas formas de aplicação de fertilização de base (na presença e ausência). O hidrogel utilizado foi um copolímero de poliacrilato de potássio (K2S2O8). Os resultados apontam que a adição de hidrogel promove melhorias na capacidade de retenção de água dos substratos, contudo, é influenciada pela sua composição e pela presença de fertilizantes químicos. Quanto maior a Condutividade Elétrica (CE) do substrato, menor é o potencial de hidratação do hidrogel. A forma de aplicação do hidrogel, se seco ou pré-hidratado, não influencia a capacidade de retenção de água pelos substratos. O hidrogel aplicado no substrato, uma vez desidratado, mantém sua capacidade de reidratação.

Recently, incentives have been provided in many countries, including Canada and Denmark, to produce biochar for construction usage. This is done because biochar is carbon negative and can help achieve the emission reduction goal of 2030. This technical note aims to analyze the efficiency of biochar in soils with varying grain size distribution for enhancing water retention capacity (WRC). The combinations of biochar content and grain size distributions corresponding to the maximum and minimum efficiency were explored. Artificial Neural Network (ANN) based model for predicting Soil Water Characteristic Curve (SWCC) as a function of soil suction and grain size distribution was developed. A new factor (the ratio of fine (silt + clay) and coarse (sand) content) was proposed for the interpretation of the efficiency of biochar in soils. The newly developed model is able to predict SWCC reasonably well. Biochar amendment is found to influence both dry and wet sides of soils with a clay content lower than threshold content (6–8%). Beyond threshold content, the influence of biochar appears to reduce. However, in the case of high sand content soils (90%), the NWC value on the drier side is generally higher as compared to soils with lower sand content. Based on sensitivity analysis, it was found that the ratio of fine to sand content is the most influential, while biochar content is the least influential.

This work aimed to evaluate the effects of lower water levels on leaf intercellular spaces and to assess their relations with the gas exchange, anatomy, and growth of Sorghum bicolor. Experiments were conducted in a greenhouse, in which plants were subjected to three water conditions (ten replicates, n = 30): well-irrigated, decreased irrigation, and limited irrigation. Lower water levels had no significant effect on the growth of S. bicolor but increased the biomass of the roots. Moreover, the number of leaves, leaf area, and leaf size as well as the chlorophyll content were not affected by lower water levels, and no significant changes were detected for whole plant photosynthesis, transpiration, or stomatal conductance. The water content of the plants and the water potential remained unchanged. However, compared with other treatments, the decreased irrigation decreased water loss and increased the water retention. Lower water levels increased the intercellular CO2 percentage, mesophyll area, and proportion of stomatal cavities and promoted minor changes in leaf tissue and stomatal traits. The increased stomatal cavities provided higher CO2 uptake and prevented excessive water loss. Thus, modifications to the intercellular spaces promoted conditions to avoid excessive water loss while concurrently improving CO2 uptake, which are important traits for drought-tolerant plants.

Graphical abstract, Background The cumulative influence of global warming, climate abrupt changes, growing population, topsoil erosion is becoming a threatening alarm for facing food challenges and upcoming global water issues. It ultimately affects the production of food in a water-stressed environment and slows down the production with more consumption of fertilizers by plants. The superabsorbent hydrogels (SAHs) have extensive applications in the agricultural field and proved very beneficial for plant growth and soil health. These polymeric materials are remarkably distinct from hygroscopic materials owing to their multidimensional network structure. It retains a lot of water in its 3D network and releases it slowly along with nutrients to plant in stressed environment. Aim of review A soil conditioner boosts up the topology, compactness, and mechanical properties (swelling, water retention, and slow nutrient release) of soil. The superabsorbent hydrogel plays an astonishing role in preventing the loss of nutrients during the heavy flow of rainwater from the upper surface of soil because these SAHs absorb water and get swollen to keep water for longer time. The SAHs facilitate the growth of plants with limited use of water and fertilizers. Beyond, it improves the soil health and makes it fertile in horticulture and drought areas. Key scientific concept of review The SAHs can be synthesized through grafting and cross-linking polymerization to introduce value-added features and extended network structure. The structure of superabsorbent hydrogel entirely based on cross-linking that prompts its use in the agricultural field as a soil conditioner. The properties of a SAHs vary due to its nature of constituents, polymerization process (grafting or cross-linking), and other parameters. The use of SAHs in agricultural field comparatively enhances the swelling rate up to 60–80%, maximum water retaining, and slowly nutrient release to plants for a longer time.

Evaluation of soil hydro-physical properties is very important in agriculture and for sustainable management of the land resources. This investigation was conducted to assess some hydro-physical properties of soils in different land use types (LUT) selected (i.e., dry upper land (UD), lowland (LL) and residential area (RA)) at 0-15cm and 15-30cm depths in Bade Local Government Area of Northeastern, Nigeria. Soils were randomly sampled at four points in each LUT and analyzed according to standard soil analysis procedures. Results of the analyses of variance showed that LL had recorded significantly higher clay content, larger soil porosities and high-water retention properties than the other LUT. Soil structural stability index (SSI) and organic carbon (OC) were below optimal range and statistically not different across the land uses. The results also indicated non-significant differences in the hydro-physical properties within the sampling depths. The coefficient of variation (CV) revealed that, slight variation (CV

Seepage well is an emerging Low Impact Development (LID) technology that can effectively control the storm runoff. However, its rainwater infiltration rate and storage capacity still require further enhancement. By setting a horizontal infiltration structure at the bottom of conventional rainwater seepage well (CSW), an enhanced seepage well (ESW) was proposed in this study, and its infiltration performances compared with the permeable pavement (PP) and the CSW were systemically investigated using static infiltration experiment and HYDRUS-2D simulation. The results showed that the infiltration efficiency of ESW was significantly higher than that of PP and CSW, and the process of water infiltrated through soil mainly controlled the macroscopic infiltration rate. The Nash-Sutcliff Efficient (NSE) index was used to evaluate the accuracy and reliability of the HYDRUS-2D model, and the results of NSE values greater than 0.75 (varied between 0.75 and 0.91) confirmed the applicability of HYDRUS-2D to describe correctly the hydraulic behavior of the ESW system. Simulation infiltration tests showed that the ESW performed a higher average infiltration rate and fewer total runoff volume than the CSW, indicating the effectively enhancement of the infiltration and water retention capacity of ESW, especially under heavy rainfall intensities. Additionally, the ESW system exhibited an excellent runoff-control and rainwater retention capacity in an actual rainfall scenario.

Bentonite is generally used as buffer or backfill material in geological repositories and its mechanical behavior is important to affect surrounding structures. In this paper, cyclic shrinkage-swelling tests are performed on Heishan bentonite taking into account the effect of initial moisture content. Results reveal that the shrinkage-swelling behavior of Heishan bentonite relies on initial moisture content and an obvious water retention property is obtained with the increases of initial moisture content. To investigate the accurate determination of aforementioned behavior of studied bentonite during drying and wetting cycle, the captured image of digital camera and the binary image processing technique are employed in this study. A simplified analytical model is proposed to simulate the shrinkage-swelling behavior at different initial moisture contents and the model parameters are calibrated by experimental results of Heishan bentonite. Based on the model performance, the model simulation agrees well with the tests and the proposed approach is able to predict the behavior of Heishan bentonite.

Permeable asphalt mixtures are widely used to achieve good permeability of the pavements used for urban road surfaces. Based on the law of water migration in permeable road structures, the water-holding performance of permeable asphalt mixtures was analyzed and the evaluation indexes were determined. Open-graded asphalt friction course (OGFC-13) permeable asphalt mixture was selected, and the changes in the saturation, water retention, and water-holding rate of OGFC-13 permeable asphalt mixtures with different porosities were compared using water-holding equipment. The water-holding characteristics of permeable pavement materials under different seepage conditions were analyzed. A model of the relationship governing the water-holding capacity of the permeable asphalt mixture, water action conditions, and material porosity was established by a linear fitting method, and the reliability of the model was verified by comparison with laboratory test results, providing a foundation for related research on the water-holding and cooling behavior of permeable pavements.

Water resources are increasingly scarce, and in drought prone production systems, the capability of the plant to recover its adverse effects is important for yield stability. There is an urgent need to develop water-saving strategies for wheat production. Water stress at critical growth stages diminishes wheat production and has harmful effects on crop growth and development; however, regulated water deficit and potassium foliar application ameliorates its adverse effect up to a certain extent. Consequently, the water deficit effect at different growth stages of the crop with exogenous application of potassium was evaluated in a screenhouse experiment in a complete randomized design (CRD) having four repeats. Varieties of wheat, i.e. Lalma (drought resistant) and Pakhtunkhwa-2015 (drought susceptible), were sown. Water deficit, i.e. mild water stress (50% of water required for field capacity) and severe stress (no application of water), at different growth stages of the crop were imposed. Potassium (K) foliar spray (1%) from potassium sulfate (K2SO4) was applied at the respective stage subjected to water deficit levels. Internal water status, i.e. relative water content (RWC) and water retention capacity (WRC), were attained maximum at tillering stage under mild stress than the rest of the stages with maximum for Lalma. Conversely, water saturation deficit (WSD) and water uptake capacity (WUC) were higher under severe stress imposed at grain filling stage. Theses indices were maintained by foliar potassium application. Similarly, dry matter (DM) allocation varied for stress level imposition and translocation to other parts were improved under foliar K application. The chlorophyll indices, i.e., soil plant analysis development (SPAD) value, also decreased with the severity of water deficit. Grain yield was higher under stress imposition at grain filling stage than the rest of the stages, though severe water stress decreased yield significantly. The Potassium (K) foliar spray showed no prominent effect at grain filling. Canopy temperature increased with stress severity and was maintained under K foliar spray. Osmotic adjustment, water and turgor potential were affected by water stress and maintained with foliar K spray. Grain quality and biochemical traits of wheat were affected severely under water deficit. Potassium foliar spray was found to decrease the adverse effect of the water stress and hence maintained the quality and biochemical characters. It is concluded that application of foliar potassium decreases the adverse effects of water stress at any growth stage, minimises the stress indices drastic effect and maintains the internal water balance of the crop at different stages subjected to water deficit.

In situ modification of bacterial cellulose allows structural and morphological tuning which determines the crucial properties such as water absorption/retention and rheological behaviour. This work reports the effect of in situ modification carried out by adding of two biopolymers - Agar and Chitosan - to the standard culture media for bacterial cellulose synthesis. The agar modified BC (Agar-BC) frames the Bacterial cellulose (BC) network as reduced pore volume, and a much denser network, leading to lesser water absorption and further lower retention time than BC. Agar-BC also demonstrates a higher storage modulus, while the yield point is observed at a lower shear strain. This indicates densely packed behaviour of crosslinked polymer with low strain onset of plasticity. On the other hand, chitosan modified BC (Chitosan-BC) also exhibits a lower pore volume with lower densly packed structure and with lower swellability and water retention reduced to 1 hour (7 hours for BC). Chitosan-BC presents a lower modulus with a yield strain similar to that of unmodified BC. The water absorption-retention behaviour is discussed in details on the basis of relative pore shape-size distribution, fibre dimension and surface area. The mechanism of viscoelatic deformation for each of the cases is explained using a schematic illustrations of the presumed fiber morphologies.

In this study, the utilization of two types of spongilites in various addition in cement mortars has been investigated with the purpose of exploring a new application of this natural pozzolans as cement mortar additives. The influence of the addition of spongilites on the physico-mechanical properties, frost-resistance, and microstructure of cement mortars as a function of time was studied. The results revealed that the rising proportion of spongilites in cement mortars causes increase in water retention of mortars, reduction of their bulk density, increase in porosity of mortars due to the growing predominance of capillary pores maintaining sufficient mortars strengths, and slightly increase in the frost-resistance of mortars. After initial tests, partial replacement of cement in fine-grained cement mortars with hitherto unexploited spongilites seems to be very promising. Based on the achieved results, a 20% cement replacement can be recommended as optimal.

This paper presents a novel suction-controlled chamber that permits the determination of the full water retention curves of geosynthetic clay liners (GCLs) under non-uniform temperature-stress paths. It investigates field conditions encountered in brine ponds (low confining stress settings) and heap leach pads (high confining stress settings) during construction and operation stages. Consequently, the analysis of the moisture dynamics in a GCL was defined under the wetting path (construction) and drying path (operation). High vertical stresses were found to facilitate a more rapid water uptake as capillarity is established faster than at low, confined stresses. In general, the drying curves increase the water desorption over the suction range investigated due to the low water viscosity caused by high temperatures. The wetting of the GCL at 20 °C and drying at 70 °C under either low, confined stress (2 kPa) or high confining stress (130 kPa) shows a reduction in the volumetric water contents. Furthermore, on the drying path, the coupled effect of elevated temperature and high confining stress accelerates water desorption leading possibly to potential desiccation.

Background Gelling is an important way to texturizing, develop novel products, and carry bioactive compounds in the food industry. Some proteins and gums demonstrate gelling character. However, when they are mixed, the properties of the resulting gel may be improved even when some gums not gelling alone. There are many reviews in literature centered on protein-polysaccharide interactions and the use of such mixed systems as complexes. Although, the mixed gelation and particularly the effect of gum addition on the gel properties, have been scarcely approached. Scope and approach This review focused on the most used natural gums for food gelling purposes and their effect on the microstructure, rheological properties, and water retention capacity of mixed gels to serve as a guide for the design of gelling mixed systems. This insight can allow protein-gum-based gel properties to be tuned for specific food applications. Key findings and conclusions Gum addition to a protein system induces structural changes in the tridimensional red of the gel that can improve its rheological properties and water holding capacity depending on the structure, molecular weight, density, and nature of the charge of the biopolymers used. Additionally, pH, ionic strength, protein-gum ratio and concentration of the gum are critical factors during gel formation.

To conduct landslide risk assessment and assess the consequences of dam and levee failures, it is important to understand the overall failure evolution process that ranges from small-strain initiation to large-strain post-failure runout. To achieve this goal and simulate such landslide events, emerging large-strain numerical approaches, such as the material point method (MPM), show promising potential as tools to model the entire instability mechanism. While successfully incorporating multi-phase interactions in granular porous media. Soil–water interaction in unsaturated soils is critical when dynamic hydraulic loads act on levees, such as when the fluvial upstream water levels oscillate and in episodes of heavy rainfall infiltration. Recently, MPM has been successfully used in many geotechnical engineering applications, which in turn motivated further advancements of multi-phase formulations. This study presents an application of a novel single-point two-phase MPM formulation to model unsaturated soils subjected to transient hydraulic boundary conditions. The potential of this approach is discussed by analysing a large-scale slope failure experiment. Results are compared with the finite-element method and limit equilibrium method. It is concluded that similar results are obtained at small strains, but MPM allows the post-failure behaviour to be estimated, which is essential for risk management.

In this study, we focused on the synthesis of polymeric hydrogels that will support the sorption and controlled release of urea, which is a rich nitrogen source, from aqueous solutions and their usability in agricultural applications. N, N-Dimethylacrylamide (DMAAm) and Starch (St) were selected as monomers and their superior properties such as chemical stability, high sorption properties, biocompatibility, and the presence of modifiable groups were utilized. A redox polymerization technique was used to create a poly(DMAAm-co-St) based hydrogel that was then modified with acidic and basic agents to improve the properties of starch. The synthesized, acid-and base-modified hydrogels were named DSt, DSt1, and DSt2, respectively. Swelling analyses were performed to examine the structural and morphological properties of DSt, DSt1, and DSt2 hydrogels, and Fourier-Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analyzers (TGA) were used. Intense cross-linking, porosity and the presence of hydrophilic groups were successfully detected by instrumental analysis and swelling results. The successful results of urea sorption of DSt, DSt1, and DSt2 hydrogels show that they can both minimize the harmful effects of urea in the environment and contain the nitrogen necessary for plants. At the same time, urea sorption behaviors were evaluated in terms of sorption isotherms and thermodynamic properties, and it was observed that urea sorption conformed to the Langmuir isotherm. The urea release results showed that DSt, DSt1, and DSt2 hydrogels exhibited different release properties in different pH solutions and these results reached 94% at pH 6-8, 100% at pH 6, and 100% at pH 8-10, respectively. As a result of the gradual decrease in the water resources on the earth, the increase in the use of fertilizers in agricultural production, and the insufficient use of fertilizers, our study draws attention to the development and support of materials that absorb/store water, and forms of controlled release fertilizers and provides potential ease of application.

Sandy soil has a low ability to absorb and store low water, low nutrient content, and a high water evaporation rate, so it is not suitable to be used as agricultural land. Superabsorbents can be used to overcome these weaknesses. The purpose of this study was to measure the abilities of the superabsorbents, including water holding, swelling, and water retention of sandy soil enriched with superabsorbent, and to analyze the chitosan-graft-poly(acrylic acid) superabsorbent characteristics. The superabsorbent was prepared by mixing a chitosan solution with ammonium persulfate as an initiator and acrylic acid, which had been neutralized with KOH. Then, the mixture was cross-linked with N,N′-methylenebisacrylamide (MBA). The resulting superabsorbent gel was dried in an oven and then crushed for analysis. The results showed that an increase in chitosan concentration increased the gel fraction, swelling, reusability, and water holding. Meanwhile, an increase in chitosan concentration decreased water retention in sandy soils. The swelling kinetics can be predicted using the pseudo-second-order model with high accuracy (R2 value of 0.99).

The objective of this study was to compare the traditional cooking method with sous-vide cooking at various cooking temperatures and times on the initial yield, peak force, and elastic modulus of semitendinosus (ST) beef. This study also examined the colour properties, cooking loss, and water retention of ST beef. Sous-vide samples were cooked inside vacuumized pouches at temperatures 60, 70, and 80 ℃ for 3 and 6 h. Meanwhile, the traditional cooking method was treated at 90℃ for 30 min. Reduced the initial yield, peak force, and elastic modulus of ST beef could be attained in 6 h at 60 ℃. Higher temperature and prolonged cooking time seem to cause meat to be tougher, likely due to the longitudinal myofibrils shrank. In terms of water retention and cooking loss, sous-vide cooked at 60 °C (regardless of cooking time) significantly exhibited better water retention and lower cook loss. This mild cooking temperature also best preserved the colour properties of lightness (L*) and redness (a*) than the other treatments.

Biochar application to a structurally poor tropical soil could potentially alter the soil’s aggregate strength and hydraulic properties. However, very few field studies have investigated the impact of biochar on the aggregate strength and hydraulic properties of tropical soils. A field experiment was therefore conducted to investigate the short-term effects of rice straw biochar on soil hydraulic properties and aggregate stability of an Acrisol in Ghana. The biochar was broadcast at rates of 10 t ha−1 and 20 t ha−1 as single applications that were incorporated into the top 20 cm of the soil using a spade and then the soil was levelled using a rake. Field saturated hydraulic conductivity and laboratory-measured soil water retention, aggregate stability and water-repellency were determined 10 months after the biochar application. Biochar increased aggregate stability against fast wetting by up to 33% compared to the control. This implies that biochar might improve the stability of aggregate of an Acrisol against slaking and erosivity of heavy rainfall. However, aggregate stability against slow wetting and mechanical breakdown after pre-wetting were unaffected by the biochar. Biochar did not affect field saturated hydraulic conductivity, water retention characteristics and water-repellency. Further field studies on weathered tropical soils with low native soil organic matter is recommended to elucidate the effect of repeated biochar addition on soil hydraulic and aggregate characteristics.

This research was conducted to purpose preparing and characterization various types of hydrogels such as blending, composite and grafting. This was done by reacting monomers such as acrylamide (A.M), methyl acrylate (M.A) and polymers. Polyvinyl Pyrrolidine (PVP) and carboxymethyl cellulose (CMC) with pectin was prepared from citrus peels. Hydrogel polymers (graft, blend and composite) were characterized using different techniques such as Fourier Transformed Infrared spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). The results of the reactions were identical to the theoretical expectations. The study was conducted to find out some properties such as swelling in water and absorption at different temperatures 25 °C and 20 °C, and the results were shown as a (559.9%, 429.2%) and (515.2%, 363.2%) respectively.

Thermal desorption is an effective approach to removing petroleum hydrocarbons from soil. However, the resultant environmental function and revegetation potential of the soil can be reduced by high...

The effect of fly ash content on the properties (fluidity, apparent density, water retention, strength, and bonding strength) of mixed aggregate plastering mortar is mainly studied in this paper. T...

The aim of this study was to observe the efficiency of ozone transferred by an airstone bubble diffuser, using two ozone generators with different output of ozone (5 g.h–1 ‒ G1; 15 g.h–1 ‒ G2). The retention of ozone in ozonised distilled and potable water and the devitalisation effects on E. coli in the water were also noted. Ozone was introduced to two types of potable water of different composition intended for mass consumption, (MC)a and (MC)b, distilled water, and well water intended for individual consumption. The devitalisation effect of ozone on E. coli in well water (WW) and added to potable and distilled water was observed. The results of our study showed that under the conditions used, the level of ozone during ozonisation with G1 increased more rapidly in distilled water and after termination of ozonisation, the retention of ozone in distilled water was a little lower in comparison with the potable water. The devitalisation of E. coli either naturally present in the water or added to it required the level of ozone close to or equal to 0.25 mg.l–1.

Soil physical quality is largely determined by interphase interactions at variable moisture content. This phenomenon allows us to consider the water retention curves as functions of the water content and its thermodynamic potentials as indicators of the soil physical quality and its dynamics. Diagrams of the physical quality of soils represented by water retention curves with areas of dominance of certain physical mechanisms and forces responsible for the interaction of physical phases were obtained for Eurasian soils included in the database (more than 400 samples) and grouped by five FAO/USDA textural classes. Original instrumental methods using centrifugal, gravitational, and temperature physical fields for water removal made it possible for the first time to obtain the thermodynamic characteristics of water retention in the entire range of soil water potential from 0 to 1 million J/kg. The main fundamental result is a physically based methodology for diagnosing the limiting (critical) values of the soil water content and its thermodynamic potentials, which divide the areas of dominance of various forms of soil moisture, physical forces, and mechanisms of interphase interactions on the diagrams of the physical quality of soils. The significance of non-capillary surface forces and mechanisms controlling water retention and physical quality of soils is shown. The results of determination of the optimal ranges of water content for Eurasian soils of different textures and geneses in connection with their soil-ecological and technological functions and services specify practical significance of this study.

Aim. On the basis of multivariate analysis, to differentiate einkorn wheat accessions by the water-holding capacity of leaves and ears and the parameters of these organs at the level of species and genotypes. Methods. The water-holding capacity was assessed by the moisture-yielding coefficient which was determined by the method of N.N. Kozhushko (Kozhushko, 1988). Differentiation of einkorn samples was carried out by the method of principal components in the interpretation of A.V. Korosov (Korosov, 1996). Results. Triticum monococcum UA0300113, Syria, and UA0300282, Hungary were characterized by the lowest specific moisture-yielding coefficients: for the second and flag leaves, respectively, (mg / cm2) 10.9, 7.0 and 11.4, 10.7; ears – the same samples as well as Triticum boeoticum UA0300401, Ukraine-Crimea: (mg / cm) 29.6, 28.2, 25.4. With an increase in the size of the lamina, there is a tendency to a decrease in its specific moisture yield. The samples of eincorn are differentiated into 4 clusters corresponding to the species. Conclusions. T. monococcum UA0300113, Syria, and UA0300282, Hungary are relatively drought tolerant. The complex of features characterizing leaf and spike size in combination with the moisture-yielding coefficients processed by the method of principal components makes it possible to differentiate einkorn oaccessions by species and genotype. Keywords: einkorns, moisture yield, drought resistance, leaf, ear.

Five thawing methods such as flow water thawing, ultrasonic flowing water thawing, air thawing, microwave thawing and low temperature thawing were used, and the physical, chemical properties and structure of mackerels after thawing were assessed. The results showed that the low temperature thawing had the best water retention, lower protein and fat oxidation. The microwave thawing had the shortest thawing time, but uneven heating leads to partial maturation. Air thawing prolonged exposure to air leads to high levels of protein and fat oxidation. The flow water thawing had better water retention than that of the ultrasonic flowing water thawing, only the thawing time was slightly longer than that of the ultrasonic flowing water thawing. In general, the low temperature thawing performed well after thawing. The flow water thawing used only 1/43 of the low temperature thawing's elapsed time after sacrificing some acceptable qualities. Thus, flow water thawing is more suitable for thawing frozen mackerel.

Total soil suction is considered to be the accumulative influence of matric and osmotic suction, assuming that the soil is biologically inert. However, there are several biological activities occurring in soil media, which result in the degradation and precipitation of organic/inorganic substances in the soil pores and around the soil surface. These biological activities may influence the soil pore structure and hence, the water retention of the soil. This study investigates the influence of the most common biological activity, degradation of organic matter in the soil pores, on the suction characteristics of the soil. The water retention behavior of the soil admixed with 10% (by weight) organic waste (banana peel, genus Musa) is estimated at different time intervals during the degradation process using dewpoint PotentiaMeter. Marginal changes in the water retention behavior were observed up to 14 days degradation period, however the soil tend to regain its initial suction characteristics after the degradation stabilizes. The organic content decreased from 10 to 3.23% during 14 days of degradation period and a marginal change in the van Genuchten fitting parameters n and α parameters were recorded. The n parameter varied only 4% in 14 days degradation period while corresponding change in α was recorded from 2.7 × 10–4 to 2.2 × 10–4. This study reports no significant change in the water retention behavior of soil during the degradation period of 28 days.

Biochar is one of the best and economical soil amendments as it helps in carbon sequestration, retains soil nutrients, increases water retention capacity of the soil, attracts more beneficial micro...

In this study, experimentally simulated ultra-rapid and super-large water inrushes was plugged effectively using superabsorbent polymers (SAPs). The SAPs are mainly composed of sodium polyacrylate and possess a core–shell structure at the micro-level, as described through multiple characterization methods. Swelling and flow experiments in a purpose-built apparatus revealed that the SAP can absorb ≈ 300 times more water than its own weight and displays an excellent water retention capacity. Most importantly, when evaluated in a visual model test, the SAP effectively plugged gushing water with high water pressure and a large and/or rapid flow rate; furthermore, the plugging time can be adjusted. Through the experiments, we delineated the plugging mechanism. These research results have important scientific significance and engineering value for reducing and controlling the occurrence of water inrush disasters in karst areas.

The impact of time-dependent unsaturated behaviour of virgin and the impact of cation self-diffusion on the time-dependent unsaturated behaviour of exhumed geosynthetic clay liner (GCL) specimens were investigated using a chilled mirror hygrometer. Total suction values (after 7 weeks’ water homogenisation) are reported for ten virgin (six different bentonites) and one GCL exhumed after exposure to the thermo-hydro-mechanical (THM) conditions in Antarctica. The time-dependent unsaturated responses of four different virgin GCLs 1 day and 1 week after hydration are compared with the results at homogenisation and the implications discussed. For the suction (0.1–300 MPa) and water content range (5–140%) examined, the post-water homogenisation water retention behaviour of the GCLs is affected by bentonite characteristics. At a given gravimetric water content, the total suction of GCLs increased with increasing smectite content and total soluble salt content and decreased with increasing total bound cation content in the bentonite. Cation self-diffusion also increased the total suction in the GCL exhumed after exposure to Antarctic THM conditions. It is concluded that the impact of cation self-diffusion on the unsaturated behaviour of a GCL during its time in service before exposure to pollutants needs to be considered in designing hydraulic and gas barriers.

This paper examines two needle-punched geosynthetic clay liners' water retention behaviour at high suction ranges using the vapour equilibrium technique where super-saturated salt solutions controlled the relative humidity. This study shows that the bentonite form and its mineralogy affect the absorption/desorption of GCLs and their corresponding water retention curves. In particular, a granular bentonite-based GCL was found to absorb more and release less water than a powdered bentonite-based GCL due to its higher montmorillonite content and larger pores. The water retention curves of both GCLs exhibited very little hysteretic behaviour at high suction. Repeated wetting-drying cycles shifted the WRCs of both GCLs slightly downward with minimal impact on their degree of hysteresis.

One of the main threats of our time is the increasing water demand not only globally, but also locally. These are often met at the expense of ecological water demand, jeopardizing the structural and operational conditions necessary to maintain good ecological status in aquatic and wetland habitats. This is why it is of great importance to explore possible water retention options. In 2019, based on the long-term data series on the water level of River Tisza, we studied the frequency and extent of flooding in the floodplain between Tiszabercel and Gávavencsellő, where there are valuable wetlands, including a ‘sanctuary’-type backwater. This was necessary because recently the floodplains have undergone negative changes. Their water volume has gradually decreased, their valuable wildlife has become rarer, some of them have completely dried out in the autumn and even one of them has burned out. From the analysis of the examined 48-years data, it could be concluded that flooding was relatively frequent in the sampled area, but the extent of water coverage had no significant effect either in space or time. It was also found that only water levels above 700 cm (based on the water meter of Tiszabercel, 98.36 mBf) could adequately ensure that the water bodies are filled up and flushed out. However, there is little chance of this, because of four reasons: (1) water levels of this height are becoming rare; (2) the duration and height of high water levels are mostly short in time; (3) water levels of several water bodies are artificially decreased; (4) the drainage effect of the River Tisza – which has been significantly incised after the river regulation – prevails in the area. Due to all, in the future, there would be a great need to maintain the water levels in the floodplain wetlands as efficiently as possible after the floods – for which we have made specific proposals for the places and methods to preserve the ecologically necessary amount of water.

To explore the effect of biochar on alleviating plant drought stress after being applied to soil, we prepared biochar using rice straw as raw material according to different pyrolysis temperatures (400, 600 and 800 °C) and reaction atmosphere (CO2 and N2). The effect of different pyrolysis conditions on the water retention performance of biochar was studied. The early high water-retaining biochar materials were selected and wheat seeds were selected for the verification experiment of returning to the field in pots. Biochar with high porosity (specific surface area and total pore volume) and more surface hydrophilic functional groups (mainly –OH and –COOH) can indeed improve soil water retention performance. It is mainly reflected in the increase in the dry weight and fresh weight of wheat and the soil moisture content in the treatment group with the addition of biochar water retention agent. Among them, the growth rates of fresh weight and dry weight of wheat in the C800 treatment group were 11.51% and 10.64%, and the soil moisture content increased by 1.89%. It is worth noting that the application of biochar cannot completely alleviate the impact of drought stress on plants, but it can reduce the amount of water irrigation to a certain extent. Considering the quality of biochar, the biochar material (C800) prepared under the pyrolysis temperature of 800 °C and the reaction atmosphere of CO2 has high water retention performance.

Although forests play important roles in the hydrological cycle, there is little information that relates the water retention capacity of litter in areas under passive restoration, especially in Cerrado savannas. This study relates litter levels to water holding capacity and effective water retention among forest fragments under different passive restoration stages: 46, 11, and 8 years to better understand litter hydrological functions in the Cerrado. Water retention capacity and effective water retention capacity of litters (unstructured materials, branches and leaves) in the field were monitored on a monthly basis. Total litter accumulation at 46 years was significantly higher than that of the other succession stages. Unstructured litter mass was significantly higher than that of leaves and branches. The 46-year stage had the highest water holding capacity in the leaf fraction, followed by unstructured material and branches. Although the water holding capacity was lower in the oldest restoration, this site showed the highest efficiency under field conditions. The process was quickly reestablished, as the 11-year restoration showed results closer to that for the 46-year stage in comparison to the area at 8 years. Thus, passive restoration plays a key role in soil water maintenance due to the influence of litter in Cerrado savannas. Deforestation and the imminent need of restoring degraded sites, highlight the need for further studies focused on better understanding of the process of forest restoration and its temporal effect on soil water recovery dynamics.

There is a need to develop sustainably sourced products that can address the needs for improved water retention in soils, slow the release rate of fertilizers (to prevent leaching and downstream eutrophication), and control soil pH for use in agriculture. This article investigates the use of industrial kelp solid waste extracted alginate (IW) slurries to produce soil amendment beads, potentially improving soil water retention, acting as slow-release fertilizers (SRFs), and combined with limestone controls soil pH levels. Alginate extracted from the IW was determined to have a lower guluronic (G) to mannuronic (M) acid ratio than pure laboratory-grade (LG) alginate (0.36 vs. 0.53). Hydrogels produced from the IW alginate achieved significantly higher equilibrium swelling ratios (1 wt% IW = 1.80) than LG hydrogels with similar concentrations (1 wt% LG = 0.61). Hydrogel beads were impregnated with ammonium nitrate and potassium chloride to produce potential SRFs. The release rates of K+ and NO3− nutrients from the produced SRFs into deionised water were decreased by one order of magnitude compared to pure salts. The nutrient release rates of the IW-based SRFs were shown to be similar to SRFs produced from LG alginate. Hydrogel beads were impregnated with limestone, and it was determined that the alginate-based hydrogels could significantly decrease the nutrient release rate. Using industrial kelp solid waste extracted alginate slurries shows potential for soil amendments production. This report emphasises, for the first time, the use of a crude alginate product in soil amendment formation. Further, it demonstrates slower release rates and soil pH control.

Puerto Boyacá tiene distintas herramientas que hacen que el municipio posea potencial de crecimiento económico a nivel regional. A proyección el crecimiento urbano también va ir de la mano, como un factor determinante en el imaginario de la ciudad. La enseñanza de las grandes urbes nos deja que, hay que resolver el crecimiento de la ciudad desde un pensamiento urbanístico sostenible, entendiendo la ciudad como ser superficial que se relaciona simbióticamente con la naturaleza dejando una huella de bajo impacto. Por tanto, la propuesta urbana persigue que el crecimiento de la ciudad gire en torno a las actividades de recreación, ecoturismo y ambiente como motor de crecimiento urbano con relación al río Magdalena. Mediante la idea de Ciudad esponja, se logrará una comprensión mayor en la adaptación resiliente del entorno urbano a fenómenos naturales como las inundaciones, de esta manera, se busca crear una nueva experiencia enfocada a la vivencia del agua. Puerto Boyacá has different tools that make the municipality have potential for economic growth at the regional level. A projection urban growth will also go hand in hand, as a determining factor in the imaginary of the city. The teaching of large cities tells us that we must solve the growth of the city from a sustainable urban thinking, understanding the city as a superficial being that is symbiotically related to nature, leaving a low-impact footprint. Therefore, the urban proposal pursues that the growth of the city revolves around recreation, ecotourism and environment activities as an engine of urban growth in relation to the Magdalena River. Through the idea of Sponge City, a greater understanding will be achieved in the resilient adaptation of the urban environment to natural phenomena such as floods, in this way, it seeks to create a new experience focused on the experience of water Pregrado

Manipulating the retention of unfrozen water in freezing contaminated soil to achieve prolonged bioremediation in cold climates remains unformulated. This freezing-induced biodegradation experiment shows how nutrient and zeolite amendments affect unfrozen water retention and hydrocarbon biodegradation in field-aged, petroleum-contaminated soils undergoing seasonal freezing. During soil freezing at a site-specific rate (4 to -10 °C and -0.2 °C/d), the effect of nutrients was predominant during early freezing (4 to -5 °C), alleviating the abrupt soil-freezing stress near the freezing-point depressions, elevating alkB1 gene-harboring populations, and enhancing hydrocarbon biodegradation. Subsequently, the effect of increased unfrozen water retention associated with added zeolite surface areas was critical in extending hydrocarbon biodegradation to the frozen phase (-5 to -10 °C). A series of soil-freezing characteristic curves with empirical α-values (soil-freezing index) were constructed for the tested soils and shown alongside representative curves for clays to sands, indicating correlations between α-values and nutrient concentrations (soil electrical conductivity), zeolite addition (surface area), and hydrocarbon biodegradation. Heavier hydrocarbons (F3: C16-C34) notably biodegraded in all treated soils (22-37% removal), as confirmed by biomarker-based analyses (17α(H),21β(H)-hopane), whereas lighter hydrocarbons were not biodegraded. Below 0 °C, finer-grained soils (high α-values) can be biostimulated more readily than coarser-grained soils (low α-values).

Rainfall leading to a variation of the groundwater regime has been considered as a main factor that caused slope failures in many regions in the world, particularly in Tunisia, where roads were recently well damaged under intensive precipitations. The installation of drilled horizontal drain can be an improvement alternative technique which affects the flow path, reduces the pressure in the soil by reducing the groundwater location. This study examines the effectiveness of drilled horizontal drains to stabilize the residual slope in a physical model. This is conducted in relation to the water retention property of the soil. So, in this study, different types of soils characterized by their corresponding water retention curves were considered. Using the proposal model implemented in CODE-BRIGHT software, we discuss many of the issues of the drain’s efficiency basing on the water pressure and the displacement field changes. The paper discusses also the role of the main parameters which characterize the water-retention of the soil, such volumetric water content at saturation and air-entry suction.