Aleksandra Drizo

Conventional seedling substrates such as rockwool and peat raise environmental concerns associated with disposal and resource extraction. Here, we investigate nanoclay–agarose hydrogels as candidate sustainable and biodegradable alternatives for seed germination and early plant growth under greenhouse conditions. Agarose hydrogels incorporating sodium bentonite nanoclay (NC) or activated carbon (AC) were prepared and evaluated for their structural, thermal, and biological performance using Brassica rapa (bok choy) as a model crop. Structural and physicochemical analyses revealed lamellar architectures, spectral features consistent with agarose–filler interactions, and composition-dependent thermal decomposition profiles. Dried NC hydrogels exhibited more open structures than the comparatively compact AC hydrogels. After 15 days under greenhouse conditions, NC40 (40 wt% nanoclay relative to agarose) achieved 100% germination and the highest mean fresh and dry biomass among the substrates compared for biomass, including rockwool and peat pellets. Over 42 days of soil burial, pure agarose and AC hydrogels showed more extensive visible breakdown consistent with biodegradation of the agarose matrix, whereas NC hydrogels retained their structural form for longer. These findings highlight nanoclay–agarose hydrogels as biodegradable, eco-engineered substrates with the potential to replace conventional growing media and advance sustainable agriculture.

Anthropogenic phosphorus (P) release from human activities continues to degrade freshwater systems, underscoring the need for effective and sustainable approaches to P removal and management. This study investigates steel slag–chitosan–nanoclay hydrogel composites as a waste-derived alternative to metal-doped biopolymer hydrogels for P removal from wastewater and stormwater. Steel slag aggregates (SSAs), a by-product of steel manufacturing, were incorporated into chitosan-based hydrogel matrices to produce composite sorbents derived from waste materials with potential for cost-effective application. Two formulations (SSA20 and SSA40) were synthesized and compared with a chitosan–nanoclay–iron (CH/NC/Fe) reference hydrogel. Phosphorus adsorption affinity was evaluated using a standardized 24 h batch protocol at environmentally relevant concentrations representative of municipal wastewater (10 mg P L⁻¹) and stormwater or agricultural runoff (1 mg P L⁻¹). The SSA40 composite exhibited the highest P adsorption affinity (Rd = 2.39 ± 0.22 L g⁻¹), outperforming both standalone SSA and the Fe-based hydrogel reference. Scanning Electron Microscopy and Energy-Dispersive X-Ray Spectroscopy (SEM–EDX) analyses revealed strong polymer–slag interactions and metal–phosphate associations, consistent with coupled adsorption and precipitation mechanisms. The SSA-based hydrogels also exhibited self-induced acidification (pH 3.3–4.2), enhancing phosphate uptake while providing intrinsic pH buffering. This study introduces a stable, waste-derived hydrogel composite and demonstrates a reproducible, environmentally relevant batch-testing approach for comparative evaluation of hydrogel phosphorus sorbents, supporting evidence-based strategies for sustainable phosphorus pollution control.

Enteric viruses in wastewater remain a persistent public health threat. Conventional treatments often achieve only modest viral log₁₀ reductions and can generate toxic disinfection byproducts, but high-energy advanced processes are often unaffordable. Antiviral phytoremediation, which involves virus removal mediated by plants and their rhizosphere microbiota, offers a low-cost, low-energy alternative; however, it has scarcely been studied. A bibliometric analysis of ~23,000 wastewater treatment studies (1976–2025) identified only 30 virus-targeted records within plant-based treatment branches, representing ~0.13% of the total corpus. This critical review structures antiviral phytoremediation into a four-barrier framework: (i) sorption/filtration, (ii) rhizosphere-mediated inactivation, (iii) plant internalization, and (iv) intracellular degradation. Pilot and full-scale studies provide strong support for the first two barriers, whereas evidence for internalization and intracellular degradation is limited, mainly laboratory-based, and often inferred from molecular rather than infectivity assays. Standalone constructed wetlands typically achieve ~1–3 log₁₀ virus reductions, but hybrid configurations that combine wetlands with complementary processes achieve ~3–7 log₁₀ reductions, with performance varying between enveloped and non-enveloped viruses and across climates. This review distills design principles for cost-effective hybrid systems and identifies methodological and governance priorities, positioning rigorously designed phytoremediation as a scalable part of climate- and pandemic-resilient wastewater infrastructure.

Presence of pathogenic viruses in wastewater pose a potential threat to public health. Conventional treatment methods often yield moderate viral reduction and toxic byproducts, whereas advanced technologies are underutilised due to their high cost and energy demands. Antiviral phytoremediation emerges as an affordable, eco-friendly and sustainable approach for removing viruses. However, recent bibliometric analysis on wastewater treatment methods from 1976–2025 revealed that only ~0.4% of total literature (~23,000) was related to antiviral phytoremediation suggesting critical knowledge gaps persist. This critical review provides insights into viral removal mechanisms, recent advancements, practical applications, and challenges and opportunities. Antiviral phytoremediation offers a promising multilayer of viral removal mechanisms (i.e., sorption/filtration, rhizosphere-mediated inactivation, internalization, and intracellular degradation mechanisms). Hybrid systems integrating constructed wetlands (CWs) with complementary technologies could achieve high removal efficiencies (i.e., ∼3.0–7 log₁₀ reductions) compared to standalone CWs (i.e., ∼1–3 log₁₀). Although phytoremediation efficiency is moderate for viruses (i.e., ∼45–84%) relative to heavy metal removal (i.e., ∼70–100%), emerging technologies (i.e., CRISPR gene editing, engineered microconsortia, and biosensors) offer promise for enhancement, which is still at proof-of-concept levels. Hybrid antiviral phytoremediation approaches provide sustainable infrastructure supporting public health, climate adaptation, and pandemic preparedness.

The excess loading of nutrients generated by agricultural activities is a leading cause of water quality impairment across the globe. Various management practices have been developed and widely implemented as conservation management strategies to combat water pollution originating from agricultural activities. In the last ten years, there has also been a widespread recognition of the need for nutrient harvesting from wastewaters and resource recovery. In Europe’s Northern Periphery and Arctic (NPA) areas, the expertise in water and runoff management is sporadic and needs to be improved. Therefore, the objective of this research was to perform a comprehensive review of the state of the art of Good Agricultural Practices (GAPs) for the NPA region. A set of questionnaires was distributed to project partners combined with a comprehensive literature review of GAPs focusing on those relevant and/or implemented in the NPA region. Twenty-four GAPs were included in the inventory. This review reveals that there is a large level of uncertainty, inconsistency, and a gap in the knowledge regarding the effectiveness of GAPs in nutrient reduction (NRE), their potential for nutrient recycling and recovery (NRR), and their operation and maintenance requirements (OMR) and costs. Although the contribution of GAPs to water quality improvement could not be quantified, this inventory provides a comprehensive and first-of-its-kind guide on available measures and practices to assist regional and local authorities and communities in the NAP region. A recommendation for incorporating and retrofitting phosphorus retaining media (PRMs) in some of the GAPs, and/or the implementation of passive filtration systems and trenches filled with PRMs to intercept surface and subsurface farm flows, would result in the enhancement of both NRE and NRR.

The aims of the present study are to verify the performance of four first-order hydraulic models and identify the model that best described the kinetics of the chemical oxygen demand (COD) removal in constructed wetlands. Three horizontal subsurface-flow constructed wetlands (HSSFCWs) were examined: two were planted with Typha latifólia and one was left unplanted. Each HSSFCW received 50 L of secondary effluent daily, resulting in a hydraulic retention time of 3.2 days. The COD concentrations were determined throughout the HSSFCWs and compared in terms of the coefficient of determination with estimated values provided by hydraulic models. The performance of the models was verified under two different conditions: (1) without, and (2) with evapotranspiration (ET) effects. Among the studied models, the plug-flow hydraulic model revealed the poorest performance, whereas the modified plug-flow model (incorporating the coefficient of decay resistance) was the model that best described COD removal kinetics throughout the HSSFCW. The incorporation of water losses by ET improved the performance of all of studied models.