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Human activity is accompanied by the introduction of excessive amounts of artificial materials, including geosynthetics, into the environment, causing global environmental pollution. Moreover, climate change continues to negatively affect global water resources. With the intensification of environmental problems, material reusability and water consumption limitations have been proposed. This study replaced synthetic soil additives with biodegradable materials and analysed the potential and sustainable processing of natural fibrous materials, which form problematic waste. Waste fibres are the basis of innovative soil water storage technologies in the form of biodegradable and water-absorbing geocomposites (BioWAG). We analysed the influence of BioWAGs on plant vegetation and the environment through a three-year field experiment. Furthermore, biomass increases, drought effect reductions, and biodegradation mechanisms were analysed. Natural waste fibres had a positive influence, as they released easily accessible nutrients into the soil during biodegradation. BioWAGs had a positive influence on the biometric parameters of grass, increasing biomass growth by 430 %. Our results indicated that this is an effective method of waste fibre management that offers the possibility to manufacture innovative, environmentally friendly materials in compliance with the objectives of circular economy and the expectations of users.

The colonization and biodegradation of the superabsorbent polymer component of water absorbing geocomposite by microorganisms occurring in the soil were investigated using a pot experiment. The polymer used in this study was technical cross-linked potassium polyacrylate (tKPA). It was placed inside a plastic skeleton structure covered with a polyester fabric sheath and incubated in non-sterile Haplic Luvisol soil sown with grass for nine months. After this time, we noticed a 77.88% reduction of 4.25 g of the tKPA initial dry mass. The highest number of soil microbes that colonized and utilized tKPA as the sole carbon and energy source was found after the first month of incubation. It ranged from 4.02 log10 CFU g−1 of water absorbed by tKPA for fungi and protists to 6.99 log10 CFU for bacteria; during the next eight months, the number decreased to 3.05 and 5.63 log10 CFU, respectively. Bacillus megaterium isolate 37SBG and the Acremonium sclerotigenum – Acremonium egyptiacum complex isolate 25SFG shown to possess the ability to degrade tKPA were selected among the microorganisms that colonized the superabsorbent polymer. After 60 days of incubation of these microorganisms in mineral media supplemented with tKPA as the sole nutrient source, 280.50 mg of the initial polymer dry mass declined by 30.28% and 20.50% for 37SBG and 25SFG, respectively. In addition, after 30 days of growth in a medium mimicking the composition of grass root exudates that was additionally enriched with ultra pure cross-linked potassium polyacrylate (upKPA), 17.21% of the 267 mg initial dry mass of upKPA was degraded by B. megaterium 37SBG. Enzymatic activity similar to lignin peroxidase appears to be connected with this process. The tKPA geocomposite component was also effectively colonized by phytopathogens from the genus Phytophthora. Their numbers ranged from 0.70 to 2.26 log10 CFU g−1 of water absorbed by tKPA after 5 and 12 months, respectively, of the geocomposite incubation in the soil. In addition, some colonized tKPA microorganisms were able to limit the multiplication of the pathogen. The mycelial growth of Phytophthora cactorum and Rhizoctonia solani was inhibited in the presence of the A. sclerotigenum–A. egyptiacum complex isolate 25SFG. We concluded that the colonization of tKPA by both microbes with the ability to biodegrade it and phytopathogenic oomycetes could limit the soil application of geocomposite as a plant growth support. The biodegradation of tKPA by soil bacteria, fungi, and protists seems to also be important for the reduction of the amount of polymer residues deposited in the soil. In addition, this study expands our knowledge about antagonistic interactions between polymer degrading microbes and soil-borne pathogens.

Superabsorbent polymers (SAPs) are used in agriculture and environmental engineering to increase soil water retention. Under such conditions, the swelling pressure of the SAP in soil affects water absorption by SAP, and soil structure. The paper presents the results of swelling pressure of three cross-linked copolymers of acrylamide and potassium acrylate mixed at the ratios of 0.3%, 0.5% and 1.0% with coarse sand and loamy sand. The highest values of swelling pressure were obtained for the 1% proportion, for coarse sand (79.53 kPa) and loamy sand (78.23 kPa). The time required to reach 90% of swelling pressure for each type of SAP differs. Samples of coarse sand mixed with SAP K2 in all concentrations reached 90% of total swelling pressure in 100 min, while the loamy sand mixtures needed only about 60 min. The results were the basis for developing a model for swelling pressure of the superabsorbent and soil mixtures, which is a fully stochastic model. The conducted research demonstrated that the course of pressure increase depends on the available pore capacity and the grain size distribution of SAPs. The obtained results and the proposed model may be applied everywhere where mixtures of SAPs and soils are used to improve plant vegetation conditions.

Various applications of superabsorbent polymers (SAP) include the use of these materials in agriculture and environmental engineering to increase soil water retention. Under such conditions, there is water absorption of the SAP in soil under load. This paper presents the results of absorbency under load (AUL) of a cross-linked copolymer of acrylamide and potassium acrylate mixed at ratios of 0.3%, 0.5% and 1.0% with coarse sand and sandy loam. The mixtures were subjected to loads equivalent to 10, 20 and 40 cm of soil. The highest differences in AUL values for both soils, compared to the control sample, were obtained after 24 hours and at a maximum load of 5.9 kPa, which corresponds to a load of a 40 cm thick topsoil layer. The AUL was 71.4 g∙g−1 for coarse sand and 52.7 g∙g−1 for sandy loam with a 1.0% SAP addition, which corresponded to 24.0% and 18.0%, respectively, of the absorption in the control sample. All the conducted tests revealed a significantly low rate of water absorbency, which is especially important for capturing the water that infiltrates into the soil profile. The results demonstrate that water absorption by SAPs decreased with the increase in SAP addition.

Climate change induces droughts that are becoming more intensive and more frequent than ever before. Most of the available forecast tools predict a further significant increase in the risk of drought, which indicates the need to prepare solutions to mitigate its effects. Growing water scarcity is now one of the world&rsquo, s leading challenges. In agriculture and environmental engineering, in order to increase soil water retention, soil additives are used. In this study, the influence of a newly developed water absorbing geocomposite (WAG) on soil water retention and soil matric potential was analyzed. WAG is a special element made from geotextile which is wrapped around a synthetic skeleton with a superabsorbent polymer placed inside. To describe WAG&rsquo, s influence on soil water retention and soil matric potential, coarse sand, loamy sand, and sandy loam soils were used. WAG in the form of a mat was used in the study as a treatment. Three kinds of samples were prepared for every soil type. Control samples and samples with WAG treatment placed at depths of 10 cm and 20 cm were examined in a test container of 105 &times, 70 &times, 50 cm dimensions. The samples had been watered and drained, and afterwards, the soil surface was heated by lamps of 1100 W total power constantly for 72 h. Soil matric potential was measured by Irrometer field tensiometers at three depths. Soil moisture content was recorded at six depths: of 5, 9, 15, 19, 25, and 30 cm under the top of the soil surface with time-domain reflectometry (TDR) measurement devices. The values of soil moisture content and soil matric potential were collected in one-minute steps, and analyzed in 24-h-long time steps: 24, 48, and 72 h. The samples with the WAG treatment lost more water than the control samples. Similarly, lower soil matric potential was noted in the samples with the WAG than in the control samples. However, after taking into account the water retained in the WAG, it appeared that the samples with the WAG had more water easily available for plants than the control samples. It was found that the mechanism of a capillary barrier affected higher water loss from soil layers above those where the WAG had been placed. The obtained results of water loss depend on the soil type used in the profile.

Due to the growing awareness and the need to reduce the environmental impact of textiles, there is a pressing rationale to use natural materials or fibres in environmental engineering. One solution to achieve energy sustainability is to develop sustainable technologies to gradually replace non-renewable fossil fuels. One of technology is water-absorbing geocomposite (WAG). WAG is an innovative technology that supports water management and the vegetation of plants and is used, among others, in environmental engineering and agriculture. WAG can be produced in biodegradable WAG version, which is also environmentally friendly. The paper provides an evaluation of the influence of time of installation and biodegradation on the mechanical, hydraulic, and chemical properties of used textiles. The biodegradation of geotextiles was analyzed in real time, and their parameters were determined after one vegetation season. Needle-punched nonwovens made from wool and linen or reinforced by jute mesh were biodegraded already after the first vegetation season. Significantly better mechanical properties were observed in nonwovens produced from the same materials, but reinforced by seams. All types of geotextiles were characterised by sufficient resistance to biodegradation that allowed maintaining vegetation and proper operation of WAG at least for one vegetation season. Biodegradable geotextiles installed in soil provide instantaneous protection, and their gradual discomposure fosters plant vegetation.

Surface waters polluted by nutrients from agricultural sources or sewage can change their trophic state into high productive and rich in nutrient content. In particular, phosphates are often regarded as the main hazard because they may activate eutrophication. This article presents the studies conducted in order to understand better the process of phosphate build-up in surface waters of Strzegomka River at the inflow and outflow from Dobromierz Reservoir, Lower Silesia, Poland, Central Europe. The Dobromierz Reservoir is the source of drinking water for over 25,000 people. Daily changes in phosphate concentrations were analysed during the hydrological year XI 2000–X 2001 and in the long-term monthly changes over the period of 15 years (2000–2014). Phosphate concentrations monitored in Strzegomka River showed great changeability. Peak phosphate concentrations reaching 1.70 mg /L were noted in the catchment in the autumn of the hydrological year 2000/2001. The mean concentration of phosphates on the...

One of the most important among the numerous applications of superabsorbent polymers (SAPs), also known as hydrogels, is soil improvement and supporting plant vegetation in agriculture and environmental engineering. Currently, when water scarcity involves water stress, they are becoming still more commonly used for water retention in soil. As it turns out, one of the major factors influencing the superabsorbent polymers water retention capacity (WRC) is the load of soil. The study presents test results of absorbency under load (AUL) of SAPs. The object of the analysis was cross-linked copolymer of acrylamide and potassium acrylate, of a granulation of 0.50–3.15 mm. The authors analysed the water absorption capacity of the superabsorbent polymers under loads characteristic for 3 different densities of soil (1.3 g∙cm−3, 0.9 g∙cm−3, 0.5 g∙cm−3) and three different depths of application (10 cm, 20 cm, and 30 cm). Soil load and bulk densities were simulated by using weights. The experiments were conducted with a Mecmesin Multitest 2.5-xt apparatus. The obtained results demonstrate a very significant reduction in water absorption capacity by SAP under load. For a 30 cm deep layer of soil of bulk density of 1.3 g∙cm−3, after 1 h, this value amounted to 5.0 g∙g−1, and for the control sample without load, this value amounted to more than 200 g∙g−1. For the lowest load in the experiment, which was 0.49 kPa (10 cm deep layer of soil of a bulk density of 0.5 g∙cm−3), this value was 33.0 g∙g−1 after 60 min. Loads do not only limit the volume of the swelling superabsorbent polymer but they also prolong the swelling time. The soil load caused a decrease in the absorption capacity from 338.5 g∙g−1 to 19.3 g∙g−1, as well as a prolongation of the swelling time. The rate parameter (time required to reach 63% of maximum absorption capacity) increased from 63 min for the control sample to more than 300 min for the largest analysed load of 3.83 kPa. The implications of soil load on superabsorbent polymer swelling are crucial for its usage and thus for the soil system. This knowledge might be employed for the more effective usage of superabsorbent polymers in agriculture and environmental engineering, in which they are commonly used to retain water and to support plant growth.

The study presents the results of experiments with a new type of water-absorbing geocomposite and its influence on the strength of biotechnological protection. The geocomposite influences the increase of water retention in soil and the improvement of the conditions of plant vegetation. The increase in the shearing strength of roots reached 66.7% for shrubs and 20.1% for grass. Increased growth of the root system and the above-ground parts of both shrubs and grass was noted.

Chemical cross-linking and the high molecular weight of superabsorbent copolymers (SAPs) are the two main causes of their resistance to biodegradation. However, SAP particles are colonized by microorganisms. For the purposes of this study, the dry technical copolymer of acrylamide and potassium acrylate containing 5.28 % of unpolymerized monomers was wrapped in a geotextile and incubated in unsterile Haplic Luvisol soil as a water absorbing geocomposite. The highest number of soil bacteria that colonized the hydrated SAP and utilized it as the sole carbon and energy source was found after the first month of incubation in soil. It was equal to 7.21-7.49 log10 cfu g(-1) of water absorbed by the SAP and decreased by 1.35-1.61 log10 units within the next 8 months. During this time, the initial SAP water holding capacity of 1665.8 g has decreased by 24.40 %. Moreover, the 5 g of SAP dry mass has declined by 31.70 %. Two bacteria, Rhizobium radiobacter 28SG and Bacillus aryabhattai 31SG isolated from the watered SAP were found to be able to biodegrade this SAP in pure cultures. They destroyed 25.07 and 41.85 mg of 300 mg of the technical SAP during the 60-day growth in mineral Burk's salt medium, and biodegradation activity was equal to 2.95 and 6.72 μg of SAP μg(-1) of protein, respectively. B. aryabhattai 31SG and R. radiobacter 28SG were also able to degrade 9.99 and 29.70 mg of 82 mg of the ultra-pure SAP in synthetic root exudate medium during the 30-day growth, respectively.