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 article presents a comprehensive and cross-cutting review of key marine waste issues, taking into account: sources, fate, risks, transport pathways, threats, legislation, current challenges, and knowledge gaps. The growing amount of both human-created waste in seas and oceans and waste reaching marine ecosystems from land is one of today’s challenges for the global economy and the European Union. It is predicted that if no decisive steps are taken to limit the amount of this type of waste, there may be more plastic waste than fish in the oceans after 2050. The influence of microplastics and nanoplastics on living organisms remains undiagnosed. Within the international and EU law, solutions are being developed to properly manage waste on board ships and to reduce the impact of processes related to the recycling of the vessels on the environment. Currently, over 80% of ships are dismantled in the countries of South Asia, in conditions that threaten the environment and the safety of workers. After World War 2, large quantities of chemical weapons were deposited in the seas. Steel containers with dangerous substances residing in the sea for over 70 years have begun leaking, thus polluting water. For many years, radioactive waste had also been dumped into marine ecosystems, although since 1993 there has been a total ban on such disposal of radionuclides. The impact of the COVID-19 pandemic on marine waste generation has also been presented as a significant factor influencing marine waste generation and management.

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.

Sustainability emphasises the importance of increasing the resource efficiency of infrastructure. The usage of geosynthetic materials in civil and environmental engineering can significantly influence sustainability at the planning and design stages of infrastructure construction projects. They are used in many different applications in construction and environmental engineering, as they provide a better and longer performance and less costly solutions than traditional materials (such as sand, gravel, concrete and cement). Additional benefits can be achieved by combining geosynthetics with various recycled materials as substitutes for high-quality natural materials. In this paper, the importance of sustainability in geosynthetics-based solutions is discussed. The possibilities of using geosynthetics in sustainable development have been analysed and the benefits resulting from their application, such as the reduction in carbon footprint and release of greenhouse gases and saving water and other natural resources, have been assessed. Innovative solutions that support mitigation measures, adaptation to climate change and achievement of sustainable development goals have been presented.