Waves can cause significant accumulation of pore water pressure and liquefaction in seabed soils, leading to instability of foundations of marine hydrokinetic devices (MHKs). Geostatic shear stresses (existing around foundations, within slopes, etc.) can substantially alter the rate of pore pressure buildup, further complicating the liquefaction susceptibility assessments. In this study, the development of wave-induced residual pore water pressure and liquefaction within sandy seabed slopes supporting MHK structures is evaluated. Unlike most earlier studies that excluded the impact of shear stress ratios (SSR) on the residual pore pressure response of sloping seabeds, asymmetrical cyclic loadings are considered herein for a range of SSRs. To obtain wave-induced loading in the seabed (and cyclic shear stress ratios, CSRs), the poroelasticity equations governing the seabed response, coupled with those for fluid and structure domains, are solved simultaneously. Utilizing an experimental model based on anisotropic cyclic triaxial test data that includes CSR and SSR impacts, an equation for the rate of pore pressure buildup is developed and added as a source term to the 2D consolidation equation. Numerical investigations were performed by developing finite element models in time domain. The models were calibrated using particle swarm optimization method and validated against wave flume experimental data. The results indicate that the consideration of static shear stresses has led to sudden rise in residual pore pressures followed by fast dissipations at early and late time steps, respectively, beneath the structure. The exclusion of SSR is shown to cause significant overestimation of pore pressure accumulations at late cycles, potentially causing significant overdesign of MHK foundations. The impact of proximity to the free drainage boundary, CSR amplitude, and loading frequency on the accumulation of residual pore pressure is illustrated. The residual liquefaction susceptibility of the seabed is shown to decline by increase of the seabed slope angle.

It is known from the literature that the rheological behavior of soils is largely dependent on the water content in pastes and soil organic matter forming the basis of organomineral soil gels. With an increase in soil moisture, gels can swell. As a result, the viscosity of the soil paste should change. The objective of this study was to assess the effect of soil moisture on the viscosity of soil paste. Arable soil horizons were used in this work: sod-podzolic, gray forest, leached chernozem, and chestnut. During the experiments, the soil moisture was changed, whereas the water content in the pastes in each soil type remained unchanged. The viscosity of the soil paste was determined by vibration viscometry, and the size of organomineral particles in pastes was determined by laser diffractometry. Two paste viscosity peaks depending on the soil moisture were obtained for all samples studied. The paste viscosity peaks were explained from the perspective of changes in the structure of humic substances in organomineral gels upon reaching critical concentrations: micelles-supramolecular formations-fractal clusters. Apparently, the transition between structural forms of humic substances under mechanical action on pastes is accompanied by the disintegration of large gel particles and the formation of a more balanced form of humic substances at a given water content.

Polybrominated diphenyl ethers (PBDEs), a type of brominated flame retardant, are of global concern due to their environmental persistence, bioaccumulation, toxicity, and resistance to conventional remediation methods. In this study, the electrochemical reduction of 2,2 ',4,4 '-tetrabromodiphenyl ether (BDE-47) with Pd/Metal foam electrodes (Ni, Cu, and Ag) was investigated. The effect of Pd loadings was explored, and the results show that Pd loading enhances the debromination performance, with 15.16%Pd/Ni foam exhibiting the best efficiency, followed by 9.37%Pd/Cu and 10.26%Pd/Ag. The degradation mechanisms for Pd/Ni and Pd/Ag are primarily hydrogen atom transfer, while for Pd/Cu, electron transfer dominates. Among the reduction products, Pd/Ni foam shows the highest debromination capability. The impact of electrolytes, current intensity, and bromination degrees of PBDEs was evaluated for 15.16%Pd/Ni. The results reveal that the presence of electrolytes inhibits BDE-47 degradation; the degradation rate of BDE-47 increases with current density, peaks at 4 mA, and decreases as current rises; and 15.16%Pd/Ni foam can effectively degrade PBDEs with varying bromination levels. Additionally, cycling tests show a decrease in efficiency from 94.3% (first cycle) to 56.58% (fourth cycle), attributed to Pd loss and structural damage. The findings offer valuable insights for developing efficient, sustainable catalytic materials for the electrochemical degradation of PBDEs and other persistent organic pollutants.

Uranyl ions (UO22+) are the form of uranium usually dissolved in water and are radioactive and can cause serious damage to the environment. Adsorption of uranyl ions is a critical method for removing and safely storing radioactive materials that harm the environment. It is also an important tool for combating water and soil contamination, managing nuclear waste and environmental sustainability. Polymer-based composites were developed for this purpose. Polymer-based composites enable the efficient removal of harmful and radioactive uranium compounds from water and soil. Through the incorporation of polymers and fillers (such as zeolite), materials with specific properties capable of adsorbing uranyl ions with high efficiency can be designed. The ratio of the components constituting the composites can be adjusted to optimize the adsorption capacity, as well as the chemical and thermal behaviors. Two composites were created: P(MA-Z50), consisting of ethylene glycol dimethacrylate (EGDM), methacrylic acid (MA), and zeolite, and P(MA-Z75), which contained a higher amount of zeolite. These composites were synthesized at room temperature and analyzed using various techniques such as Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). The study investigated the effects of adsorbent quantity, adsorbate concentration, temperature, time, and pH on adsorption efficiency and capacity. The Langmuir adsorption isotherm provided the best fit for uranium (VI) adsorption. The results showed that rapid adsorption occurred within the first 100 min, with the rate slowing down until equilibrium was reached after 360 min. The pseudo-second-order kinetic model best described the adsorption process.

Plastic packaging has increased concerns about human health and the ecosystem due to non-biodegradability. Several biopolymers, such as cellulose, starch, and proteins, are being explored, and cellulosic residue from agricultural biomass is suitable to overcome this predicament. Herein, cellulosic residue fibers (ACR) extracted from alfalfa were used to prepare biodegradable films by solubilizing them in ZnCl2 solution and crosslinking the chains with calcium ions (Ca2+) and sorbitol. Box Behnken Design optimized the ACR, CaCl2, and sorbitol amounts against the responses of water vapor permeability (WVP), tensile strength (TS), and elongation at break (EB). The optimized film combination was found to be 0.5 g ACR, 461.3 mM CaCl2, and 1.05% sorbitol, making a 12 x 12 cm2 film, with a TS of 16.9 +/- 0.4 MPa, EB of 10.1 +/- 0.3%, and WVP of 0.47 +/- 0.11 x 10- 10 g.m- 1.s- 1. Pa- 1. It was translucent, blocked UVB light, followed Peleg's water absorption kinetics, displayed anti-oxidant activity, and biodegraded within 35 days at 24 % soil moisture. The ACR film extends the shelf life of strawberries by two more days compared to polystyrene film. The outcome offers a novel path to utilize and conserve natural resources and mitigate plastic perils, promoting a circular bioeconomy and sustainability and a win-win situation between the environment and farmers.

Mining and using underground resources demand high water usage, producing significant waste with environmental risks. Methods like electrokinetics prove effective in accelerating dewatering and stabilizing structures. This research provides the results of experimental investigation on dewatering silty tailings obtained from Sungun Tailings Dam (East Azerbaijan, Iran) using the electrokinetic water recovery method. Previous studies primarily examined the electrokinetic process in steady-state flow and saturated soil, with limited exploration of unsaturated soil parameters. In this research, the electrokinetic process in steady-state flow was initially investigated, and the saturated electro-osmotic permeability was determined. Subsequently, experiments were conducted in non-steady-state flow and unsaturated conditions, measuring the influential parameters with soil moisture sensors and tensiometers. Results show that decreasing sample moisture through electro-osmotic flow increases negative pore water pressure. Tailings' electrical conductivity is more influenced by moisture content, with a steeper reduction slope concerning volumetric moisture reduction over time. pH assessments show soil acidity on the anode side and alkalinity on the cathode side. Higher applied voltage gradients result in increased maximum power consumption. Importantly, the results caution against assuming that higher applied voltage improves the electro-osmotic process, as it may lead to issues such as deep sample cracking, void space creation, interrupted electrical flow, and energy loss.

The coastline of the Dardanos, a district of & Ccedil;anakkale, T & uuml;rkiye, suffers from saltwater intrusion due to excessive extraction of groundwater for domestic usage and also agricultural activities. Thus, the salinity level increased, and much of the land became unusable. The electrokinetic remediation method was employed to reduce the salinity level in the soil samples in laboratory conditions. The sample used in remediation is silty agricultural soil, with pH value and electrical conductivity (EC) of which are 8.33 and 1282 mu S/cm respectively. In the lab-scale experiments, three different types of electrodes, aluminum, copper, and galvanized steel, were used in the tests. For each type of metal, electrode pairs were placed in the soil that was filled in a plastic container. Current variation was monitored while 1 VDC/cm was applied to electrodes. Average electrical conductivity reduces to 13.5%. As a side effect, all electrodes suffered from heavy corrosion which may be prevented by using anti-corrosion additives to reduce damage for future applications.

This study investigates the influence of four soil improvement methods-microbially induced carbonate precipitation (MICP), electrokinetics (EK), chemical additives, and a combination of EK and chemical additives-on the dispersivity, mechanical properties, and microstructure of dispersive soil. A series of tests was designed to evaluate the effectiveness of these methods on dispersive soil. Both the original and treated soil samples were tested to assess changes in soil properties, including dispersivity, plasticity, pH, unconfined compressive strength (UCS), shear strength, and microstructure. Dispersivity was assessed using pinhole tests, crumb tests, double hydrometer tests, and exchangeable sodium percentage tests. The experimental results indicate that the combined EK and chemical additives method significantly reduces the dispersivity and plasticity of the dispersive soil compared with the other methods, leading to improved UCS. The EK and chemical additive methods individually demonstrate effective modification under a voltage of 48V and an additive content of 4%, respectively, enhancing the shear strength of the dispersive soil. MICP does not significantly improve the dispersivity of dispersive soil, but it does enhance the shear strength of the treated soil, with a particularly notable increase in the internal friction angle. Overall, the combined method shows more remarkable improvements in the dispersive soil than any single method. In summary, the combination of EK and chemical additives has significant potential for improving the dispersivity and mechanical properties of dispersive soil.

The agricultural industry prioritizes minimizing crop yield losses caused by pests, making it essential to develop effective, safe and sustainable pesticide formulations. Hydrogels are promising carriers for pesticide delivery, due to their high surface area, large pore volume, and pore size. In this study, we synthesized Cassia fistula (CA-g-AA) and its derivative carboxymethylated Cassia fistula-grafted polysodium acrylate hydrogel (CMCA-g-AA) using free radical polymerization, with N, N'-methylene bisacrylamide (MBA) as a crosslinker, for the ex-situ encapsulation of dinotefuran. Characterization was performed using FTIR, 13C CPMAS-NMR, SEM, TGA, rheology, and XRD. The maximum swelling capacity of hydrogels was investigated in distilled water. CA-g-AA and CMCA-g-AA hydrogels exhibited a dinotefuran loading percentage of 37 and 39% and released dinotefuran for 26 and 29 h, respectively. The dinotefuran release kinetics was analyzed by using the Korsmeyer-Peppas and Higuchi models. Under drought like conditions, CMCA-g-AA-treated soil sustained plant growth for 7 days, compared to CA-g-AA (5 days) and untreated soil (3 days). The novel hydrogel CMCA-g-AA enhanced soil water absorption and retention along with highlighting its potential for extended pesticide release. Thus, the developed CMCA-g-AA hydrogel is an efficient strategy for sustainable agriculture.

Coal waste, a by-product of coal extraction, adversely poses environmental hazards as it releases harmful substances into the air, water, and soil, damaging the ecosystem and localized biodiversity. The coal-to-energy sludge-seeded bioconversion shows its potential as an environmentally friendly technology to mitigate the harmfulness of coal-derived hazards. This study uses blended coal and anaerobic digestion sludge in batch reactors at a mesophilic temperature (35 degrees C) to generate methane-rich biogas for energy production and waste elimination. Nutrient solution and ethanol were added as stimuli to boost bioactivities and enhance gas production. These results showed the potential of lignite coal in biomethane generation over an extended period, even with a lower volume of sludge addition. Adding nutrients and ethanol enhances the ultimate biogas production as an extra feed for microorganisms and as a key parameter in increasing the bioavailability of coal. The ultimate biogas production from the kinetic model indicates a remarkable volume of 111504 mL/g-sludge using lignite with 20 mol ethanol compared to the blank reactor with 701 mL/g-sludge of biogas production. The intricate analysis of results highlights the complex interplay between coal, sludge, nutrients, and additives, where varying factors impact methane production rates. Despite challenges in interpreting data, this study underscores the potential for managing coal waste through wastewater utilization, transforming it into methane-rich biogas-a sustainable green technology for energy production.