The existence of rock weathering products has an important effect on the infiltration of water in the soil. Understanding the mechanism of water infiltration in a mixed soil and weathered rock debris medium is highly important for soil science and hydrology. The purpose of this study is to explore the effects of mudstone hydrolysis on water infiltration in the soil under different mixing ratios (0-70 %) of weathered mudstone contents. Soil column experiments and numerical modelling were used to study the processes of hydrolysis of weathered mudstone and water infiltration in the mixed medium. The results revealed that water immersion can cause the dense mudstone surface to fall off, thus forming pores, and that the amount of these pores first increase but then decrease over time. The disintegration of post-hydrolysis mudstone debris occurs mainly among particles ranging from 2-2000 mu m, predominantly transforming sand particles into finer fractions. Increasing the mudstone content in the soil from 0 % to 50 % enhances the infiltration rate and cumulative infiltration volume. However, when the mudstone content exceeds 50 %, these parameters decrease. The mudstone weathering products promote water infiltration in the soil within a certain range of mudstone contents, but as the ratio of weathered products increases, excessive amounts of mudstone hinder the movement of water in the soil. The identified transformation phenomenon suggests that the infiltration capacity of mixed soil will not scale linearly with mudstone content. The findings enable some mitigation strategies of geologic hazards based on the hydrological stability in heterogeneous environments.

Cementations bind sand/soil particles via physical and chemical interactions to form composite solids with macroscopic mechanical properties. While conventional cementation processes (e.g., silicate cement production, phosphate adhesive synthesis, and lime calcination) remain energy-intensive, bio-cementation based on ureolytic microbially induced carbonate precipitation (UMICP) has emerged as an environmentally sustainable alternative. This microbial-mediated approach demonstrates comparable engineering performance to traditional methods while significantly reducing carbon footprint, positioning it as a promising green technology for construction applications. Nevertheless, three critical challenges hinder its practical implementation: (1) suboptimal cementation efficiency, (2) uneven particle consolidation, and (3) ammonia byproduct emissions during ureolysis. To address these limitations, strategic intervention in the UMICP process through polymer integration has shown particular promise. This review systematically examines polymer-assisted UMICP (P-UMICP) technology, focusing on three key enhancement mechanisms: First, functional polymers boost microbial mineralization efficacy through multifunctional roles, namely microbial encapsulation for improved survivability, calcium carbonate nucleation site provision, and intercrystalline bonding via nanoscale mortar effects. Second, polymeric matrices enable homogeneous microbial distribution within cementitious media, facilitating uniform bio-consolidation throughout treated specimens. Third, selected polymer architectures demonstrate ammonium adsorption capabilities through ion-exchange mechanisms, effectively mitigating ammonia volatilization during urea hydrolysis. Current applications of P-UMICP span diverse engineering domains, including but not limited to crack repair, bio-brick fabrication, recycled brick aggregates utilization, soil stabilization, and coastal erosion protection. The synergistic combination of microbial cementation with polymeric materials overcomes the inherent limitations of pure UMICP systems and opens new possibilities for developing next-generation sustainable construction materials.

For maintenance and water saving reasons artificial or semi-artificial (hybrid) turfs have worldwide replaced natural turfs in many football-, soccer- and hockey stadiums. For obvious sustainability reasons the polymers which replace or reinforce the natural grass should be degradable, but still maintain specific mechanical properties over a certain period of time. This study intends to design and validate a poly(butylene succinate) (PBS) which fulfils these requirements. We investigated the dependency of PBS hydrolysis on molecular mass and temperature in order to develop a kinetic model for abiotic hydrolysis, which is the limiting step in PBS biodegradation. The hydrolysis rates were found to be temperature dependent according to the Arrhenius relationship k = A * exp(- EA R*T). A molecular mass dependency of the pre-exponential factor A was established and could befitted well by a linear equation without intercept for higher molecular weights. A polynomial approach led to a better fit for the whole molecular weight range. Both models have been validated on a degradation experiment in soil and were able to predict the molecular mass degradation within the typical standard deviations by size exclusion chromatography. Furthermore, we used the models to simulate the degradation of PBS samples in soil on available long-term soil temperature data. Previously published data on the relationship between molecular weight and mechanical properties were used to forecast the loss of functionality. This prediction was then compared to traction tests of aged PBS filaments used as fibre reinforcement of football hybrid turfs. The measurements match the predictions and show that a hybrid turf system with PBS fibres can be played on for at least 5.2 years before the fibres lose their mechanical properties.

Polyoxalate, a novel intrinsically hydrolysable polyester, garners significant interest for its high costeffectiveness and versatility. However, concerns persist regarding its durability in practical applications. This study integrates bio-based poly(butylene furanoate) (PBF), which possesses remarkable barrier performance, into the poly(butylene oxalate) (PBOx) framework to synthesize poly(butylene oxalate-co-furanoate) (PBOF) with tunable degradation rates. The influence of incorporating BF units on thermal, crystalline, mechanical, and barrier properties was systematically analyzed. Results demonstrated the addition of BF units dramatically improved the balance between degradation and physical properties. Laboratory degradation experiments indicated that PBOF possessed significant degradation effects. Among them, PBOF-41 (with 41 % molar furanoate) decreased in weight by 20 % in freshwater, 70 % in an enzyme solution, and 8 % in artificial seawater within 30 days. After 28 days of degradation in soil, the residual weight was reduced to 80 % of its initial weight. Theoretical calculations and experiments have clarified the enhancement of the Gibbs free energy and energy barrier of the hydrolysis reaction by the BF unit. In summary, PBOF copolyesters have excellent gas barrier performance, adjustable thermal properties, well-balanced mechanical properties, and degradability, making them highly promising for sustainable plastic products.

Bio-tiles are a biobased alternative to conventional tiles that utilise a promising technology called microbially induced calcium carbonate (CaCO3) precipitation (MICP). This technology has low energy requirements and also sequesters carbon. Bio-tiles have been made in previous work using a submersion method, however, the process required additives such as 0.3 M magnesium chloride to achieve bio-tiles that meet international standards. The current study aimed to improve the bio-tile strength properties with CaCO3 crystal seeding and a pumping method instead of the use of magnesium that also increases ionic strength. With this technique, cementation solution containing the required calcium and urea for the MICP reaction was pumped through a sealed mould in a series of programmed treatments. The highest concentration of ureolytic Sporosarcina pasteurii with an effective urease activity of 40 mmol NH4-N/L center dot min was found to be most beneficial to the breaking strength of the bio-tiles, as were the shortest retention times of 1 h between treatments. Seeding with CaCO3 crystals offered significant benefit to the MICP process. Pre-seeding of the geotextiles was explored and the mass of seeds initially present on the geotextiles was found to have a direct improvement on the breaking strength of 21-82 %, increasing with seed loading. The highest CaCO3 seed loading tested of 0.072 g seeds/cm2 geotextile resulted in bio-tiles with a breaking strength of 940 +/- 92 N and a modulus of rupture of 16.4 +/- 1.7 N/mm2, meeting international targets for

This study proposed an improved bio-carbonation of reactive magnesia cement (RMC) method for dredged sludge stabilization using the urea pre-hydrolysis strategy. Based on unconfined compression strength (UCS), pickling-drainage, and scanning electron microscopy (SEM) tests, the effects of prehydrolysis duration (T), urease activity (UA) and curing age (CA) on the mechanical properties and microstructural characteristics of bio-carbonized samples were systematically investigated and analyzed. The results demonstrated that the proposed method could significantly enhance urea hydrolysis and RMC bio-carbonation to achieve efficient stabilization of dredged sludge with 80% high water content. A significant strength increment of up to about 1063.36 kPa was obtained for the bio-carbonized samples after just 7 d of curing, which was 2.64 times higher than that of the 28-day cured ordinary Portland cement-reinforced samples. Both elevated T and UA could notably increase urea utilization ratio and carbonate ion yield, but the resulting surge in supersaturation also affected the precipitation patterns of hydrated magnesia carbonates (HMCs), which weakened the cementation effect of HMCs on soil particles and further inhibited strength enhancement of bio-carbonized samples. The optimum formula was determined to be the case of T = 24 h and UA = 10 U/mL for dredged sludge stabilization. A 7-day CA was enough for bio-carbonized samples to obtain stable strength, albeit slightly affected by UA. The benefits of high efficiency and water stability presented the potential of this method in achieving dredged sludge stabilization and resource utilization. This investigation provides informative ideas and valuable insights on implementing advanced bio-geotechnical techniques to achieve efficient stabilization of soft soil, such as dredged sludge. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

The PBAT (poly (butylene adipate- co-terephthalate) is a promising biodegradable material. However, it is often blend with hydrophilic polymers since its degradation rate in the aquatic environment is still limited. In this study, the blend PBAT/TPS (thermoplastic starch) films, namely BFs, were prepared by a blow extrusion approach, and evaluated for hydrolysis in four studied mediums acid (HCl, 1 M, 2 M, and 3 M), alkaline (NaOH, pH = 9, 11, and 13), phosphate buffer (pH = 7.4), and artificial seawater. The hydrolyzed BFs were characterized by weight loss, mechanical properties, scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and differential scanning calorimetry (DSC). A larger starch content in the BFs caused hydrolysis more quickly. The highest hydrolytic rate was found in the alkaline solution, followed by the acid medium. The complete abiotic hydrolysis of the BFs was 3 M HCl for 14 days or NaOH (pH 13) for 35 days. After 180 days of incubation, the film containing 70.5 % PBAT/TPS granules has been associated with the highest biodegradation rate of 76.31 % in composting.

This study focuses on mitigating the socio-economic and environmental damage of the invasive macroalga Rugulopteryx okamurae and counteracting the pollution from petroleum-based plastics by using the alga as a feedstock for polyhydroxybutyrate (PHB) production. The enzymatic hydrolysis of R. okamurae, non-pretreated and hydrothermally acid-pretreated (0.2 N HCl, 15 min), was carried out, reaching reducing sugar (RS) concentrations of 10.7 g/L and 21.7 g/L, respectively. The hydrolysates obtained were used as a culture medium for PHB production with Cupriavidus necator, a Gram-negative soil bacterium, without supplementation with any external carbon and nitrogen sources. The highest yield (0.774 g PHB/g RS) and biopolymer accumulation percentage (89.8% cell dry weight, CDW) were achieved with hydrolysates from pretreated macroalga, reaching values comparable to the highest reported in the literature. Hence, it can be concluded that hydrolysates obtained from algal biomass hydrothermally pretreated with acid have a concentration of sugars and a C/N ratio that favour PHB production.

Soil salinization restricts crop growth and yield, thereby adversely affecting agricultural development. The stage of seed germination is the most crucial and sensitive stage in the plants' life cycle and is particularly sensitive to saline-alkali stress. We investigated the effects of different hormonal priming agents, namely melatonin (MT), abscisic acid (ABA) and brassinosteroid (BR), as well as the osmopriming agent, calcium chloride (CaCl2), on the germination of wheat (Triticum aestivum L.) seeds under saline-alkali stress. Saline-alkali stress was simulated with the solution of 100 mM NaCl and 50 mM NaHCO3/Na2CO3 (9:1). The results indicated that hormonal priming agents (ABA, MT, or BR) significantly alleviated saline-alkali stress-induced inhibition of wheat seed germination. The germination rate of seeds primed with ABA, MT, or BR increased by 21.0%, 11.0%, and 10.5%, respectively. The seeds primed with ABA, MT or BR showed improved activities of alpha- and beta-amylase under saline-alkali stress, with corresponding increases in starch hydrolysis and soluble sugar content, which contributed to seed germination and embryo growth. Hormonal priming (ABA, MT, or BR) also significantly improved antioxidase activities to alleviate oxidative damage in germinating seeds under saline-alkali stress. Seeds primed with ABA (38.7%), MT (37.0%), and BR (31.3%) displayed lower malondialdehyde (MDA) content than the H2O-primed seeds. The ABA exerted the most significant promoting effect on wheat seed germination under saline-alkali stress. The promotional effect of CaCl2 on seed germination was nonsignificant compared with that of hydropriming. The results offer a theoretical and practical basis for applying seed priming to enhance the saline-alkali tolerance of wheat in production.

Contemporary reinforced concrete structures suffer from the drawback of developing micro-cracks during their service due to causes related to shrinkage and fatigue. This may compromise their technical and functional serviceability due to the possible reduction in durability which may lead to a decrease in load carrying capacity of the structure. In recent years, experimental studies on biomineralization or biocementation have shown a potential to address this issue. Biocementation is the process in which microorganisms induce the production of calcium carbonate which can improve self-healing capabilities by filling the micro-cracks and pores in the structures, similar to the traditional lime-based materials. The most used pathway of biocementation is urea hydrolysis, which is brought about by the urease enzyme secreted by ureolytic bacteria. Although there have been numerous laboratory-scale studies that have yielded positive results, the widespread adoption of this technology in practical applications is still hindered by a range of constraints. The information about the solutions to resolve these limitations is fragmented and dispersed throughout the literature. This review aims to compile state-of-the-art knowledge in one place. This article provides a detailed assessment of the challenges in the application of biocementation and suggests strategies to overcome the obstacles that hinder its use in construction projects.