Abstract
Nature-based Solutions (NbS) offer a promising, sustainable framework for addressing urban environmental challenges by harnessing the intrinsic functions of natural ecosystems. Defined as economically viable strategies inspired by nature, NbS aim to protect, manage, and restore ecosystems for mutual benefits to both people and nature. In urban and peri-urban contexts, NbS, such as green infrastructure and bioremediation, provide effective approaches to mitigating climate change, enhancing soil, air and water quality, reducing urban heat, and restoring ecological balance. Green infrastructure, comprising parks, urban forests, green roofs, and wetlands, has been shown to improve soil quality by enhancing organic carbon, nitrogen, and phosphorus accumulation, as well as fostering biodiversity. Complementarily, bioremediation strategies, including microbial remediation and phytoremediation, have proven effective in decontaminating soils laden with heavy metals, petroleum hydrocarbons, microplastics, and other pollutants, while promoting soil fertility and ecosystem services. Despite their demonstrated benefits, the efficacy of NbS is influenced by environmental factors such as soil pH, temperature, oxygen availability, and pollutant diversity. In addition, while NbS continue to evolve and their integration into urban planning represents a vital step toward creating resilient, healthy, and sustainable cities, their application in urban environments remains fragmented. Therefore, further research is required to optimize NbS interventions, scale up their implementation, and evaluate long-term impacts under urban conditions characterized by anthropogenic stressors. This review examines green infrastructure and bioremediation strategies, highlighting key case studies and evaluating their effects on soil quality and overall remediation outcomes.
1 Introduction
The concept and theme of Nature-based solutions (NbS) was already used at the beginning of the 21st century, and built upon earlier theories and fields of studies such as the applied ecology and the restoration of the biodiversity, which has been developed at different levels with concepts as the ecological engineering, green-blue infrastructures, ecosystem assessments and ecosystem services or the use of the natural capital, functioning as an “umbrella” concept (; ).
Nature-based Solutions have been only adopted later by different global institutions and their understanding and applications continue to evolve as this field develops (). Notably, the practical application of NbS remains imprecise and fragmented, largely due to ambiguities arising from the integration of diverse scientific disciplines and the absence of well-defined standards within the NbS framework. As defined by the International Union for Conservation of Nature (IUCN) and the European Commission, NbS are strategies inspired and supported by nature, economically viable, that address societal challenges by protecting, sustainably managing, and restoring natural or modified ecosystems to benefit both people and nature ().
Within urban and peri-urban areas, NbS provide sustainable approaches to address environmental challenges. By integrating nature into urban planning, they can mitigate climate change effects, improve soil, air and water quality, reduce urban heat, and restore ecological balance, which is “a state of dynamic equilibrium within a community of organisms in which genetic, species and ecosystem diversity remains relatively stable” (). Currently, nearly half of the global population resides in cities, and projections suggest that by 2050, this proportion will increase to approximately two-thirds (). This rapid expansion of urban populations needs continuous growth in built-up areas. However, unregulated or poorly planned urban development can result in unsustainable landscapes, contributing to environmental degradation, including air and water pollution, soil contamination, and the fragmentation of natural habitats (). Such ecological disruptions have already led, and will likely continue to lead, to the loss of soil biodiversity, reduced ecosystem services, and adverse public health outcomes, highlighting the need for sustainable urban planning strategies. Without an ecological consciousness among administrators, industry and citizens on the side effects of the growth of populations, NbS alone cannot be able to help in the improvement of environmental health.
In cities, NbS particularly relevant are green infrastructures. One of the most widely cited definitions, provided by the , describes green infrastructure as “a strategically planned network of natural and semi-natural areas, designed and managed to deliver a wide range of ecosystem services” (; ). Key elements of green infrastructures include parks, urban forests, gardens, allotments, floral meadows, urban farming, green roofs and walls, and wetland restoration.
Complete catalogues of the NbS studied and useful in urban areas have been recently compiled to help planners depending on the factors relevant and on the governance objectives, as , or to evidence the main NbS implemented in the urban environment and their effects, as in .
The introduction of green infrastructures in urban areas positively impacts multiple environmental aspects. They could prevent urban flooding and support water management (; ; ), reduce the urban heat island (UHI) effect, thus contributing to climate change adaptation (; ; ), and promote a more sustainable urban environment (; ; ). The UHI effect is indeed an increasingsly critical local climate issue associated with global urbanization, with significant implication on human health and energy consumption (). It refers to the phenomenon where the urban areas exhibit markedly higher temperatures than their surrounding rural counterparts. This temperature disparity results from key characteristics of densely populated urban environments, characterized by elevated anthropogenic heat emissions, greater absorption of solar radiation, lower albedo, reduced heat capacity, and diminished turbulent heat exchange.
Additionally, green infrastructures could enhance urban biodiversity (; ), reduce environmental contaminants (; ), or soil sealing (), sequester carbon (C) (), support local food production (; ), and improve the quality of life for residents ().
Another NbS that can be applied in urban areas is soil bioremediation. Over the past 6 decades, industrialization and technological advancements have led to the creation of large areas of abandoned, underused, and potentially contaminated land in cities worldwide. These areas, commonly known as brownfield sites (; ), require careful soil contamination monitoring and remediation. Unfortunately, many of these areas are also found in countries where environmental policies and regulations are not strict and legislation did not require (or encourage) the landowners to restore the environment. The remediation process is crucial not only for urban regeneration, but also for preserving soil quality, biodiversity, and the essential ecosystem services these sites provide (; ; ).
Soil pollutants can be degraded or removed using various methods, many of which can be specifically adapted for the reclamation of brownfield sites (). The methods range from physical (e.g., heat treatment, vitrification, electro-remediation, landfilling, storage), chemical (e.g., oxidation, chemical fixation, precipitation, leaching, ion exchange), biological (e.g., bioremediation), and integrated approaches (; ).
Bioremediation is generally more cost-effective and eco-friendlier than traditional physical and chemical methods and can enhance soil fertility along with several ecosystem services in urban areas, such as improved urban hydrology, heat mitigation, noise reduction, biodiversity, carbon dioxide (CO2) sequestration, bioenergy production, landscape aesthetics, social cohesion, and public health (; ). Bioremediation relies on non-toxic inputs and produces safe by-products throughout the degradation process. This method uses either naturally occurring microorganisms (microbial remediation) or plants (phytoremediation) to remove pollutants from soil effectively. Microorganisms such as bacteria, fungi, microalgae, and actinomycetes are particularly effective for reclaiming soils contaminated with organic pollutants, as they can use chemical contaminants as energy sources, metabolizing targeted compounds through redox reactions to support growth and energy conversion (). In this way, hazardous pollutants can be converted into less toxic forms. For instance, hydrocarbons can be oxidized by microorganisms, with oxygen (O2) being reduced to form CO2 and water (). As pollutants are degraded, microbial populations gradually decline as the availability of harmful substances diminishes. Microorganisms can also be used to immobilize metals in soil, causing them to precipitate, adsorb, and become fixed in the soil matrix, thereby reducing their bioavailability (; ).
Plants with high capacity to tolerate and accumulate contaminants can be used in phytoremediation technologies for the removal of both inorganic and organic pollutants from brownfield sites (; ; ). The most suitable plants for phytoremediation are those that efficiently translocate metals to their aerial parts (phytoextraction) or those that can effectively degrade organic contaminants and their by-products through phytodegradation. Combined remedial approaches using both microbes and plants have also shown promising results (). Indeed, the mutualistic relationship between plant species and microbes can enhance the bioavailability of several pollutants for more effective degradation and/or removal. Additionally, root exudates stimulate the growth of rhizosphere microorganisms, further facilitating the breakdown of organic contaminants in a process known as microbial-assisted phytoremediation (). Recent advances in bioremediation have led to the development of innovative strategies that enhance the efficiency, specificity, and resilience of both microbial- and plant-based approaches. Among these, the use of genetically engineered plants and microorganisms enables faster and more targeted degradation or immobilization of complex contaminants (). Similarly, the application of selected microbial consortia and fungal species (e.g., white-rot fungi) has shown great promise in breaking down persistent organic pollutants through enzymatic activity (). The incorporation of functionalized amendments such as biochar, compost, and nanomaterials can further improve pollutant bioavailability, stimulate beneficial microbial activity, and stabilize soil properties (). Moreover, hybrid systems that combine plants, microbes, and tailored soil amendments are gaining momentum as synergistic tools for sustainable soil remediation, particularly in complex and heavily contaminated environments (). These cutting-edge technologies not only accelerate the detoxification process but also promote long-term soil health and multifunctionality, aligning with broader goals of circular economy and green infrastructure development.
2 Green infrastructures and their impact on urban soil quality
Soils play a critical role in the urban ecosystem by supporting essential biogeochemical processes and providing key ecosystem services. However, urbanization poses a significant threat to soil integrity and health, often causing irreversible degradation.
Unsealed urban soils contribute to various ecological functions, including water filtration, C sequestration, and biodiversity support, which are essential for maintaining environmental quality and human wellbeing in cities. Therefore, the preservation and enhancement of soil quality in urban areas are crucial for sustaining ecosystem services and mitigating the adverse effects of urban expansion. Unsealed urban soils are predominantly found in green infrastructure spaces, such as urban parks and forests, allotments and under lawns and floral meadows.
The type and quality of green infrastructure significantly influences soil physical, chemical and biological properties. Despite this, research on green infrastructure has largely focused on broader environmental benefits, such as climate change mitigation, biodiversity conservation, and C sequestration, often overlooking the direct interactions between green infrastructure and soil health and quality (; ; ).
Moreover, there is a clear lack of robust results on the effects of NbS on soil quality. Looking into literature, this gap is also evident in systematic reviews on green infrastructures recently published. As an example, in the review of soil is evocated just once in all the paper, while showed that typically, NbS just look at soil erosion, while soil quality was not mentioned. Moreover, , in a bibliometric analysis on NbS, did not mention any work studying NbS effect on soil.
The only indicator well studied in literature is soil organic carbon (SOC), which is a key indicator of soil health, and green infrastructure can enhance its accumulation. A study in Berlin () compared the SOC content of sealed and green areas, revealing significant differences. In the topsoil layer (0–20 cm), sealed areas stored 3.99–7.94 kg C m-2, while green areas contained 2.16–9.52 kg C m-2. In deeper soil layers (>20 cm), sealed areas held 10.40–58.94 kg C m-2, whereas green areas stored 19.21–119.62 kg C m-2. These findings indicate that green spaces can sequester up to twice as much SOC as sealed surfaces, highlighting their role in soil health and C storage ().
Different factors such as time, the type of green infrastructure and vegetation, and green space management play a crucial role in determining soil organic carbon content in urban areas, as confirmed by multiple studies. Research conducted in Finland by and highlights the effect of time in urban parks. In particular, Setälä and colleagues analyzed 41 parks in Helsinki and Lahti, categorizing them into three age groups: old (more than 100 years old), intermediate (around 50 years old) and young parks 5–15 years old). Their findings revealed that younger parks had lower SOC content. Similarly, studied 30 parks in Helsinki and confirmed that park age significantly influences soil C content. The impact of time on SOC content is also evident on green roofs, which are key components of green infrastructure and help regulate urban temperature, reduce stormwater runoff, improve air quality, and enhance biodiversity, while also contributing to climate resilience and the overall ecological performance of cities (; ). A study in Hanover (Germany) examined 10 green roofs categorized as old (established between 1990 and 1994) or young (established between 1998 and 1999). Results showed that older roofs had the highest C content in their soil substrate, with an average SOC of 8.4%, compared to 3.4% on younger roofs ().
With respect to the type of green infrastructure and vegetation impacting SOC in urban areas, a study conducted in Leicester by examined variations in SOC across different green spaces. The authors analyzed areas covered with herbaceous vegetation (primarily lawns), shrubs and low trees, trees over 5 m, as well as backyard gardens with lawns, meadows, vegetable beds, or a combination of shrubs and lawns. Their findings revealed that backyard gardens with shrubs and trees had the highest SOC concentration (75.2 mg g-1), whereas areas dominated by herbaceous vegetation exhibited the lowest levels. On the city scale, backyard gardens with shrubs and trees, despite covering only 11% of the total green space, contributed 16% of the total SOC stock. In contrast, areas dominated by herbaceous vegetation, which make up 46% of the green space, accounted for 40% of the total C soil content. Similarly, conducted a study in The Hague (the Netherlands), comparing SOC content across different urban green spaces, including parks, street trees, urban forests, and shrub-covered areas in both the city center and suburbs. While high SOC contents were recorded in both areas, soil C density was significantly higher in the city center (12.5 ± 6.84 kg C m-2) than in the suburbs (8.45 ± 5.15 kg C m-2). Notably, shrub-covered areas stored approximately 25% of the total soil C despite occupying only 13% of the total green space. compared soil samples from urban parks in Helsinki and found that shrubby areas consistently stored more C than those dominated by herbaceous vegetation and lawns. This trend persisted across various park types, including regularly maintained parks with fertilization and irrigation, standard parks, and buffer strips between developed and natural areas. Another study in Helsinki compared SOC content in different urban green spaces, such as orchards, parks, urban forests, and street trees. Results showed that urban forest soils had the highest SOC content, while soils under street trees had the lowest (). In the same city, tree species composition was also reported to influence SOC accumulation, which was higher in parks with evergreen trees than in parks with deciduous trees, thus reinforcing the role of vegetation type in C storage ().
Green space management also has a measurable impact on SOC content. studied a park in Grozny, analyzing soil samples from three areas: an irrigated lawn, a non-irrigated lawn, and a non-irrigated lawn with trees. Their findings showed that soil from the irrigated lawn had 35% higher SOC content than the non-irrigated areas, demonstrating the role of irrigation in enhancing soil C accumulation.
Soil health in urban areas is also influenced by nitrogen (N) and phosphorus (P) levels. Green roofs serve as a prime example of green infrastructure that facilitate N accumulation in soil, as demonstrated by studies conducted in various countries. investigated this phenomenon by analyzing ten green roofs in Hanover, constructed between 1990–1994 and 1998–1999. Their findings revealed that older roofs had a higher total N content in the soil substrate, with an average of 0.34% compared to 0.24% on newer roofs.
Like organic C, N and P accumulate in urban soils depending on time. In this respect, studied a green roof in Tomblaine (France), by analyzing the initial soil substrate and reassessing it after 4 years. These findings showed a significant increase in N content, rising from 0.13% to 0.54% ± 0.2%. Similar studies were conducted in Sweden, where 15 green roofs, built between 1994 and 2014 across three cities, were considered. These analyses confirmed that older roofs had higher N content in the soil substrate, with an estimated N accumulation rate of 3.8 ± 1.0 g N m-2 year-1 (). A similar relationship exists between time and soil P content. found that total soil P content was lowest in young and intermediate parks and highest in the oldest parks, reinforcing the long-term accumulation of essential nutrients in urban soils. In another study, additionally measured N contents across three different vegetation types, including lawns, deciduous trees, and evergreen trees, in various parks. They found that soil N concentrations were lowest in lawns and highest in areas with evergreen trees (). A similar study in Helsinki (Finland) compared organic nitrogen (Norg) content in soils from orchards, parks, urban forests, and areas under street trees. The highest Norg content was recorded in the urban forest soil (0.29% ± 0.02%), while the lowest was found under street trees (0.13% ± 0.05%) (). When comparing lawns to urban meadows, soil N content was generally higher in lawns ().
Beyond the effects on soil chemical properties, green infrastructure plays a significant role in enhancing soil biodiversity. A three-year study in Cambridge (United Kingdom) compared species diversity between lawns and floral meadows, revealing that species diversity was 3.6 times higher in the meadows. Additionally, total invertebrate biomass was 25 times greater in the meadows, while the species diversity of soil nematodes remained similar between the two environments (). Soil biodiversity was also explored in a study by , who analyzed microbiological activity on green roofs of varying ages in Hanover (Germany). Their assessment of dehydrogenase activity revealed a dramatic range, from 451 μg total productivity factor (TPF) g-1d-1 on young roofs to 4,530 μg TPF g-1d-1 on older roofs. The average dehydrogenase activity was 1892 μg TPF g-1d-1 in young roofs and 2,874 μg TPF g-1d-1 in older roofs. In addition, the quantity of collembolans was measured, showing that older roofs supported a higher population of this species, with an average of 57,000 individuals m-2 on older roofs compared to 55,000 individuals m-2 on younger roofs.
Based on the findings from these studies, green infrastructure significantly influences urban soil health and indicators. However, the limited research on this topic underscores the need for further exploration into the relationship between green spaces and urban soil. A deeper understanding of this connection is crucial for developing effective strategies to enhance urban soil quality, which, in turn, can improve the overall quality of life for urban residents.
3 Bioremediation of urban soils
Urban green spaces represent a potential exposure pathway to inorganic and organic contaminants for both humans and other organisms. Soil pollution in these areas can originate from point and diffuse sources. The largest influx of contaminants into the soil from urban and commercial activities is through transport (e.g., vehicle exhaust particles, tire and brake wear particles, weathered street surface particles, brake lining wear particles), industrial emissions, (e.g., power plants, coal combustion, metallurgical industry, auto repair shop, chemical plant, etc.), domestic emission, weathering of building and pavement surface, atmospheric deposition, and waste (). As an example, lead (Pb), which is the most concerning trace element in urban areas due to its high toxicity, predominantly originates from the use of Pb-based paints, vehicle emissions and deposition of airborne particles from Pb-emitting industries. In Europe, Pb and its compounds in paints and fuels are controlled by the European Commission under the EU REACH law (Registration, Evaluation, Authorization and Restriction of Chemicals) (), which has been in effect since 2007. However, despite national and international regulations, old houses and even newly produced paints still have high concentrations of Pb and are widely commercialized mainly in low- and middle-income countries. Therefore, the high persistence and bioaccumulation of Pb in urban soils remain a significant concern ().
In addition to Pb, other trace elements are also commonly found in urban soils. Among all, the most widespread are zinc (Zn), copper (Cu) and cadmium (Cd), which are primarily associated with atmospheric deposition from traffic emissions (; ), while mercury (Hg) can originate from a variety of sources, including coal and oil combustion in power stations, atmospheric deposition from industrial plant and traffic emissions, incineration of municipal solid waste. Additionally, urban garden soils may contain Hg from the use of agrochemicals applied for plant protection ().
Organic contaminants in urban soils, such as phthalate esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) might also cause serious threats to human health and the environment. Phthalate esters raise significant concerns given their high volatility and well-documented role as endocrine disruptors (; ). Widely used as plasticizers and additives in a range of industrial products, pharmaceuticals, personal care products, and food containers, PAEs are released during their manufacture, utilization, and waste disposal (). Polycyclic aromatic hydrocarbons primarily derive from vehicle exhaust, coal combustion for cooking and heating, wood and straw burning, and high-temperature industries such as melting, cooking, and metal processing (; ). Soil organic matter has a strong capacity to adsorb PAHs, allowing these compounds to persist in soil for decades.
Other organic contaminants in urban areas include polychlorinated biphenyls (PCBs), chlorinated solvents, volatile organic compounds (VOCs), heavy petroleum hydrocarbons, dioxins and furans, and several pesticides used in home gardens (). These compounds are persistent, non-degradable, highly stabilized, strongly hydrophobic, and accumulate over time (). Their presence in soil can severely impact humans and other organisms, as they are toxic, mutagenic, teratogenic, and carcinogenic ().
A different type of urban soil contaminant is microplastics (MPs). These polymeric particles, originating from various sources, may pose direct risks to the environment and human health, either due to the particles themselves (), or through the chemical additives they carry (). Microplastics have been reported to cause significant changes in ecosystem properties and processes, plant growth, and soil communities, raising serious concerns about their long-term effects on the environment and human health ().
Bioremediation approaches can be applied either in situ or ex situ depending on the nature of contaminant, its concentration in soil, soil properties, site conditions, and logistical considerations (; ).
Figure 1 illustrates NbS-based bioremediation approaches in urban areas. In situ treatments are often more appealing and sustainable as they eliminate the need for excavating and transporting contaminated soils. The most common in situ treatments include natural attenuation, biostimulation, bioventing, biosparging, bioaugmentation, and phytoremediation (; ). In contrast, ex situ approaches require the excavation and removal of contaminated soil for treatment, either on-site or at an off-site facility; these include land farming, composting, biopiles, and bioslurry treatments (; ). Among the described bioremediation approaches, natural attenuation, biostimulation, composting, and phytoremediation are considered as NbS (Figure 1). It is noteworthy that NbS definition is not always clear-cut in the context of bioremediation. Our classification is based on the degree to which each technique aligns with core NbS principles, namely, working with natural processes and minimizing artificial or engineered interventions. The methods reported in Figure 1 prioritize the use of natural processes, intervening minimally, to enhance or support ecosystem functions. In contrast, other bioremediation approaches rely more on engineered processes, mechanical input or the introduction of non-native microorganisms. Therefore, they require active human control to achieve remediation, rather than directly harnessing natural ecosystems in their unaltered state (; ; ), and, for this reason, they fall outside the NbS scope.
FIGURE 1
Natural attenuation is commonly used in areas with low to moderate contamination levels and where risks to human health and the environment are minimal (; ). This process relies entirely on the natural ability of soil and native microbial strains to degrade, transform, or immobilize pollutants without significant active human intervention (). Regular monitoring is essential to ensure that the natural processes effectively manage the contamination without adverse effects.
On the other hand, biostimulation promotes the activity of soil native microorganisms and natural metabolic pathways by supplementing nutrients such as P, N, O2 or C, or electron donors (e.g., compost or other organic materials), to stimulate biodegradation (). While it involves some human intervention, which makes its classification as NbS debatable, it amplifies natural processes and is often aligned with NbS. Thus, given this partial alignment, we included biostimulation as an NbS (Figure 1).
Bioventing and biosparging can be applied to inject O2 in soil to enhance the microbial activity aimed at degrading organic contaminants. However, while these methods rely on biological processes, they still require active technological intervention, which makes them less aligned with the principles of NbS.
Phytoremediation is a largely studied NbS also in urban environments, for the reclamation of soils with low levels of contamination. It must be noted that often the use of this approach for the complete remediation of urban sites could not be effective, as the estimated time for remediation exceeds the overall rate of urban development. Introducing a landscape framework within urban developments can create spaces that not only support phytoremediation processes but also enhance the spatial organization and aesthetic value of public areas. This approach transforms urban landscapes into productive spaces that serve both environmental restoration and social functions (e.g., community wellbeing). This concept well aligns with the principles of NbS.
Plant species preferentially employed in brownfield sites are trees (; ; ), but there are also examples where metal hyperaccumulators have been used () or urban grassland plants (; ).
Finally, composting produces nutrient-rich OM, which can be applied to soils to improve their quality, structure, and biological fertility, improving soil biodiversity. This approach finds application also in urban environments as it contributes to reducing the volume of waste that needs to be transported to landfills or incinerators, limiting municipal waste management costs and increasing the efficiency of urban waste systems. Compost can additionally support urban farming. Indeed, community composting initiatives can provide residents with nutrient-rich soil for gardening and enhancing local green spaces.
3.1 Bioremediation of inorganic contaminants
Bioremediation techniques for soils contaminated with inorganic contaminants, also defined as Potentially Toxic Elements (PTEs), have been studied for decades (; ; ). The primary focus has been on elucidating the mechanisms of metal uptake by plants (; ; ), identifying plants capable of accumulating high levels of PTEs (; ; ), and assessing the feasibility of remediation (; ; ). For successful outcomes, a plant should ideally be able to explore the entire contaminated soil, but the rooting zone (typically 30–50 cm depth) is, in most cases, shallower than the depth of the contamination. As a result, only surface-level contamination can be treated in situ. The biomass generated during remediation could serve as a valuable resource to reduce costs, either by producing energy or being utilized in other industries. However, in many countries, biomass is classified as waste and must be landfilled, while in other countries, the lack of legislation hinders full-scale implementation (; ).
Figure 2A provides a summary of the main sources of inorganic contaminants, their effects on soil health, bioremediation techniques, and the associated ecosystem benefits.
FIGURE 2
Most studies focused on bioremediation have been conducted in controlled environments or in highly polluted soils, such as industrial or mining areas, where the contaminant concentrations are higher, and the timeframes required to observe the effects of the practice are longer.
However, in this section, we focus on studies conducted in urban areas that explore bioremediation, with a focus on phytoremediation techniques, especially phytostabilization, as well as those examining soil health more broadly, particularly the transformations induced by these techniques. Consequently, we prioritized studies from urban settings where the effectiveness of these NbS has been demonstrated, either at pilot or full scale, although their number is limited compared to the vast body of research on bioremediation, highlighting the need for further investigation before wider application in the field (). This fact could be explained by several reasons.
In urban areas, inorganic contaminants are often the result of long-term diffuse pollution, along with site-specific acute cases. Consequently, large areas with low concentrations need remediation. Although this offers an advantage for bioremediation, as chemical or physical strategies are costly and less efficient in these conditions (e.g., excavation and landfilling), the primary drawback is the time required for the process to be effective (; ). Indeed, although plants can accumulate metals relatively quickly, within a single growing season, the time required to reduce the total contamination to acceptable levels is typically too long, limiting their practical application in the field. Furthermore, studies at field scale (or full-scale) are limited due to the challenges of conducting a comprehensive bioremediation trial within the typical timeframe of a research project or industrial planning (i.e., 3–5 years). A complete bioremediation trial requires multiple stages, including site acquisition, characterization, planting, and follow-up of the experiment (). For companies, this challenge is even more pronounced, particularly in urban areas, where allotments have a monetary value that is influenced by potential future investments. The value of a remediated area is further diminished if the prospects for changing land use in the future are scarce. Another challenge, hindering the field-scale application of phytoremediation, is that, unlike chemical or physical methods, this technology does not guarantee successful outcomes due to non-controllable factors, such as extreme weather events. Specifically, effective phytoremediation requires a thorough understanding of site-specific conditions and soil chemistry in order to select the most suitable approach. This knowledge is crucial for translating laboratory findings into practical field applications, including both remediation and ongoing monitoring efforts (). Other less prominent but still significant challenges in designing and conducting field-scale studies in urban areas include the depth of contamination and the management of biomass.
Among the field studies selected for this review (Table 1), conventional phytoextraction and phytostabilization approaches were the most commonly used, with their effectiveness in reducing heavy metal pollutants such as Cd, Zn, Cu, and Pb from urban soils being widely demonstrated. Of these approaches, phytoextraction, using accumulators or fast-growing plants, garnered the most interest due to its versatility, despite certain limitations (; ).
TABLE 1
| Target species | Metal | Initial concentration (mg kg-1) | Time (years) | Accumulation | Reference |
|---|---|---|---|---|---|
| Urban grasses | Pb | 159 ± 1 | 2 | EF 3–5 BAF 0.02–0.03 | |
| Urban grasses | Zn | 333 ± 41.9 | 2 | EF 2–40 BAF 0.05–0.16 | |
| Acer, Betula, Buddleja (high concentration) | Zn | 0.5–51.4a | 30 | TC = 0.03–0.55 | |
| Acer, Betula, Buddleja (low concentration) | Zn | 0.31–8a | 30 | TC = 0.08–3.68 | |
| Noccaea caerulescens | Cd | 2 | 1 | 200 g ha-1 | |
| Noccaea caerulescens | Zn | 333 | 1 | 47 kg ha-1 | |
| SRC: Populus, Salix, Robinia | Zn | 413 | 2 | Populus (28%–1,077 g ha-1) Salix (36%–919 g ha-1), Robinia (26%–997 g ha-1 | |
| Urban grasses | Mn, Zn, Ni, Cu, Pb, Co | Mn: 504–589 Zn: 101–111 Ni: 25–30 Cu: 30–34 Pb: 40–46 Co: 7.13–8.09 Mo: 0.38–0.40 As: 4.14–4.61 Cd: 0.38–0.44 | BAFb Mn (0.89), Zn (2.32), Ni (0.63), Cu (0.92), Pb (0.62), Co (0.65), Mo (4.99), As (0.62), Cd (1.19) |
Selected studies addressing NbS for removal of inorganic contaminants in urban soils. EF, enrichment factor; BAF, bioaccumulation factor; TC, total concentration; SRC, short rotation coppice.
Phytoavailable concentrations, CaCl2 extract.
Values for mixed stands.
Studies involving hyperaccumulators primarily focused on well-known plant species, which yielded variable results at the field scale owing to differences in edaphic and pedological factors (). For instance, explored phytoextraction in urban wastelands in Brussels (Belgium) using the hyperaccumulator Noccaea caerulescens. Within the first vegetative season, they achieved results that could lead to realistic remediation timeframes (<5 years) for sites with low contamination (i.e., less than 2 mg kg-1 and 200 mg kg-1 of exchangeable Cd and Zn in the soil), effectively reducing the bioavailable fraction in the soil.
Fast-growing plants, particularly when using the short rotation coppice (SRC) technique, have also been studied to enhance plant uptake through increased biomass production in industrial and mining areas (; ). However, this approach has not been explored in urban, low-contaminated soils. In a 2-year field study, employed the SRC technique with poplar, robinia, and willow spp. These authors found that the bioavailable concentrations of Cu and Zn in urban soil decreased by 26%–36%, while the total metal pool in the soil remained unchanged. This suggests that the process was limited by the bioavailability of inorganic contaminants. The authors also noted that, while the available fraction decreased significantly, the total metal pool remained unaffected, indicating that these plants could be beneficial in a phytostabilization approach, a concept traditionally discussed in the literature ().
Phytostabilization techniques, which focus on soil recovery and biodiversity restoration rather than complete remediation, aim to restore ecosystem services while mitigating potential risks. Among these techniques, those using plants already adapted to urban environments or naturally occurring in these areas have been the most widely studied on a field scale. investigated the potential of spontaneous natural revegetation and phytostabilization with over 50 plant species on a soil contaminated with inorganic and organic compounds. Among the species considered in the study, Bituminaria bituminosa and Dactylis glomerata effectively immobilized metals in their roots, making them suitable for phytostabilization. In contrast, Daucus carota exhibited higher metal translocation to aerial parts but low biomass and metal uptake, limiting its potential for phytoremediation. The study demonstrated good adaptability of these species to the urban settings, offering a promising approach for recovering soil health in degraded areas. Similarly, used perennial grasses (such as ryegrass, Lolium perenne L.), crested wheatgrass (Agropyron cristatum L.), tall fescue (Festuca arundinacea Schreb.), and bird’s foot trefoil (Lotus corniculatus L.) for bioremediation of polluted urban soils in Bulgaria, identifying certain species with favorable bioaccumulation and translocation properties as suitable candidates for phytomanagement studies. The accumulation factors for all examined PTEs were significantly higher in the roots than in the aboveground parts, except for molybdenum, which exhibited the highest BAF (Bioaccumulation Factor) (2.16–15.69) and TF (Transfer Factor) (0.69–1.42) values. Additionally, their research showed improvements in soil microbiota, with a notable recovery of soil functionality, as indicated by a higher presence of bacteria and fungi and enhanced microbial physiological profiles at the community level. Other studies, such as have explored the use of spontaneous plant species, including Acer pseudoplatanus L. and Betula celtiberica Rothm. & Vasc., and the shrub Buddleja davidii Franch. For the recovery of urban brownfields. Their results indicated that these species adapted their phytoremediation strategies based on soil contamination levels, as they were effective candidates for phytostabilization in highly contaminated areas, while their phytoextraction capacity was more suitable for soils with low contamination.
Based on the findings from these studies, effective phytoremediation requires a tailored approach based on the contamination levels and specific environmental conditions of the site. For moderate pollution, hyperaccumulators are ideal for metal removal, while stabilizing species such as Salix and Acer are better suited for high-pollution areas, where they help immobilize contaminants. Combining these methods in soils with multiple contaminants offers a balanced and efficient solution, promoting a sustainable and long-term remediation strategy. However, newer and more innovative techniques, such as biostimulation (which induces modifications to the microbiota to increase the availability of inorganic contaminants) or alterations to soil characteristics (e.g., pH, Eh, and nutrient availability), have yet to be explored at the field level in urban areas. This gap in research should be a priority for future studies.
3.2 Bioremediation of organic pollutants
Persistent Organic Pollutants (POPs) pose a significant challenge in soil contamination. Figure 2B provides a summary of the main sources of organic pollutants, their effects on soil health, bioremediation techniques, and the associated ecosystem benefits.
These pollutants primarily result from human activities, including the rupture of underground storage tanks, pesticide application, percolation of contaminated surface water into subsurface layers, oil and fuel disposal, leaching of landfill waste, and the direct discharge of industrial waste into the soil (). The persistence of POPs in the environment due to their resistance to the environmental degradation (i.e., chemical, biological, and photolytic), exacerbates their impact, making them a long-term threat to soil health and ecosystems (; ).
This class of compounds includes pesticides, industrial chemicals such as PCBs (polychlorinated biphenyls), PBDEs (polybrominated diphenyl ethers), and PFOS (perfluorooctane sulfonate), as well as by-products of industrial processes like dioxins and furans. These substances have the potential to bioaccumulate in the food chain, affecting animals and humans, which can lead to significant health risks and ecotoxicological impacts. As a result, numerous studies have been conducted to better understand the behavior and risks of these priority pollutants (; ).
Most POPs are highly lipophilic and semi-volatile. Additionally, they can associate with atmospheric aerosols, facilitating their long-range transport and redistribution across different ecosystems. However, some POPs, such as PFOS, exhibit water solubility. Halogenated POPs, in particular, demonstrate greater resistance to degradation due to their stable molecular structures.
Biodegradation is the natural process by which living organisms, primarily microorganisms, break down synthetic chemicals through biologically catalyzed reactions, decreasing their environmental impact (). This process involves degradation of POPs into smaller, less harmful components (). Certain bacteria and fungi have evolved specialized metabolic and enzymatic pathways that enable them to utilize POPs as C and energy sources (). However, the effectiveness of biodegradation depends on the bioavailability of these pollutants, which is influenced by both their chemical properties and soil characteristics that affect microbial access (; ; ).
Bioremediation of urban soils can exploit the process of biodegradation and be further enhanced through the use of plants in combination with microorganisms. This approach, known as plant-assisted bioremediation, utilizes plants to stimulate bacterial degradation of POPs. Plant-microorganism interactions in the rhizosphere can enhance PCB degradation by fostering synergistic relationships between plant roots and the native soil microbial community, as many plant species not only thrive in PCB-contaminated soils but also stimulate indigenous microbial populations with biodegradative capabilities (; ; ; ; ; ; ).
The application of a plant-assisted bioremediation strategy in a historically contaminated area near Taranto (Southern Italy), demonstrated the effectiveness of the Monviso poplar clone (Populus generosa x Populus nigra) in promoting pollutant degradation (). Significant reductions in PCBs and heavy metals were observed in soil where poplars were planted, whereas no reduction occurred in non-vegetated areas. Additionally, microbial analyses indicated an overall improvement in soil quality and microbial activity, particularly in the rhizosphere, with effects detected up to 1 m from the trunk and at depths of 40 cm. Within just over a year of planting, the Monviso clone successfully enhanced microbial abundance and facilitated contaminant degradation, highlighting its potential as a NbS for remediating chronically polluted urban environments. In the same area, demonstrated that the Monviso poplar clone promoted a significant shift in the structure and predicted function of the belowground microbial community, revealing an increase in Proteobacteria genera known for PCB degradation and heavy metal resistance. Functional profiling using PICRUSt2 bioinformatics tool identified key genes associated with PCB transformation (bphAa, bphAb, bphB, bphC), oxidative stress response (catalase, superoxide reductase, peroxidase), and heavy metal uptake and expulsion (ABC transporters). conducted a 2-year study on a peri-urban vacant site contaminated with petroleum hydrocarbons and PCBs to evaluate the effects of two phytoremediation strategies on soil chemical, physical, and biological properties. The study compared intercropping of alfalfa (Medicago sativa L.) with hybrid black poplar (Populus canadensis) vs. monocultures of each species. Additionally, the impact of inoculation with a commercial arbuscular mycorrhizal and ectomycorrhizal inoculum was assessed in comparison to non-inoculated conditions. A key finding was that, although none of the phytoremediation treatments led to a significant reduction in organic contaminant concentrations in 2 years, they effectively improved soil health, as indicated by increased microbial biomass, activity, and biodiversity. These results highlight the positive effects of alfalfa sowing on soil microbial biomass and the benefits of intercropping in stimulating enzyme activity in soils contaminated with organic pollutants.
In the study by , a different approach was explored to promote PCB degradation, based on sequential cycles of dechlorination followed by aerobic bio-oxidation. Soil was artificially contaminated with PCBs both as a mixture and as single congeners, then aged and planted with two different plant species. To enhance degradation, alternating redox cycles were established in the plant root zone through periodic flooding and draining of the soil. Over 32 weeks, planted systems containing switchgrass (Panicum virgatum) and poplar (Populus deltoids x nigra DN34), that were exposed to alternate cycles of flooding, demonstrated superior PCB reduction compared to non-cycled planted systems. Additionally, cycled systems accumulated a higher mass of PCB transformation products, indicating more effective degradation. Notably, multiple redox cycles were required to achieve significant differences between cycled and non-cycled treatments, underscoring the importance of controlled redox fluctuations in optimizing PCB bioremediation.
Table 2 illustrates selected studies concerning the removal of organic pollutants by NbS-bioremediation approaches.
TABLE 2
| Target species | Contaminant | Initial concentration | Time (months) | Accumulation | Reference |
|---|---|---|---|---|---|
| Alfalfa | Hydrocarbons, PAHs, PCBs | 70–200 mg kg-1 (Hydrocarbons), 0.02–0.14 mg kg-1 (PAHs), 0–22 mg kg-1 (PCBs) | 16 | 51% (w w−1) (hydrocarbons) 22%–33% (w w−1) (PAHs) | |
| Poplar (Rhizosphere) | PCBs | 246 ng g-1 | 14 | 90% (w w−1) | |
| Alfalfa + Rhizobium | PCBs | 414–498 μg kg-1 | 3 | 36%–43% (w w−1) | |
| Switchgrass, poplar + flood cycling | PCBs | 499–1,120 ng g-1 | 8 | 44%–56% (w w−1) (switchgrass) 42%–57% (w w−1) (poplar) | |
| Plant-PSM combinations | PCBs | 30 μg g-1 | 2 | 29%–50% (w w−1) | |
| Rhizoremediation (willow, spruce) | PCBs | 38 mg kg-1 | 6 | 40% (w w−1) (willow) |
Selected studies addressing NbS for removal of organic pollutants in urban soils. PAHs: polycyclic aromatic hydrocarbons; PCBs: polychlorinated biphenyls.
3.3 Bioremediation of microplastics
The problem of MP pollution is undoubtedly one of the most emerging threats of environmental contamination and represents one of the greatest environmental challenges to be faced in recent decades. In the context of urban environments, one major source of MP pollution derives from individuals who improperly dispose of plastic waste. This behaviour contributes significantly to environmental pollution, leading to the accumulation of microplastics in soil.
The relentless and widespread use of plastics requires a regulamentation and some government already provided for some laws (), but the efforts to limit plastics should be more. Given its importance, this phenomenon is attracting huge attention from the scientific community and policymakers globally (; ). In the context of plastics, bioplastics represent an emerging category of materials designed to address some of the main environmental issues associated with conventional plastics, such as reliance on fossil fuels and the accumulation of plastic waste. The term “bioplastic” can refer to plastics made from renewable materials, plastics that undergo natural degradation, or both characteristics simultaneously. However, it is important to note that, like plastic materials, bioplastics may not always be biodegradable, even if they are made from renewable materials. Therefore, if bioplastics do not fully degrade, they can break down into MPs, which persist in the environment and can be taken up by different organisms ().
In general, MPs are plastic polymer particles less than 5 mm in size and resulting from the fragmentation of larger plastic products or from the direct use of industrial microgranules (e.g., in cosmetics and synthetic textiles) (). These dimensions are essentially at the core of the pollution and environmental hazard problem of MPs, as they are difficult to detect, collect and are easily dispersed over long distances in the environment, and eventually be found in a wide range of ecosystems, ranging from terrestrial to aquatic (). However, originally, early scientific studies mainly focused on the impact of MPs in marine environments, where their presence has been thoroughly documented (); instead, more recent studies have begun to highlight an equally worrying problem: the spread of these particles in agroecosystems (; ). Indeed, global studies, such as the one conducted by , have highlighted how MPs have silently invaded different soil types, from agricultural to natural areas, with varying but often alarming concentrations.
Figure 2C provides a summary of the main sources of MPs, their effects on soil health, bioremediation techniques, and the associated ecosystem benefits.
Most of the MPs present in agricultural soils often have an urban origin, deriving from various activities related to city life (). The main sources include: (i) MPs originating from synthetic fibers and cosmetic products that are not completely removed by sewage treatment plants and end up in sludge, which is used as organic fertilizer in agricultural fields; (ii) rainwater that carries MPs from roads and construction sites to agricultural areas; (iii) mismanaged urban plastic wastes, which degrade and release MPs, which enter the agricultural chain through the use of soil organic amendments (i.e., compost) derived from urban wastes. In turn, MPs of agricultural origin can reach urban soils when contaminated organic fertilizers are used in city parks and gardens. Furthermore, one of the main sources of MPs in urban soils is due to the degradation by weathering and UV radiation of abandoned or mismanaged plastic wastes (such as bags, bottles, packaging, etc.), which fragment into increasingly smaller particles ().
Despite the evidence of a direct and reciprocal link between urban and agricultural pollution, which highlights the urgency of improving urban waste management to limit the spread of MPs, the existing literature on MPs in urban soils is scarce, as it remains an emerging field compared to studies on agricultural environments and especially compared to marine environments (). In general, recent research on MPs in urban soils mainly focuses on the sources of contamination, their distribution, ecotoxicological effects, and detection methodologies. However, urban soils are highly vulnerable to pollution by MPs because, on the one hand, concentrations of these contaminants are significantly high due to intensive anthropogenic activities and, on the other hand, because the problem of MPs is added to the other pollutants resulting from urbanization, exacerbating soil degradation, reducing fertility and the capacity to support vegetation and thus threatening food security and environmental sustainability ().
Once in the soil, MPs can persist for a long time and resist chemical degradation by contributing to soil accumulation, interacting with the soil matrix and altering fundamental physical, chemical, and biological properties of the soil. Specifically, the presence of MPs in soils can affect fundamental processes such as water retention, soil aeration, soil structure and nutrient cycling (). As an example, examined the distribution of MPs in agricultural soil microaggregates, highlighting how their presence can alter soil structure, affecting porosity, and water retention capacity. Microplastics also have an impact on soil biodiversity; in particular, MPs can alter the composition and functionality of the microbial community and can be ingested by soil invertebrate organisms (such as earthworms), causing physical damage to their digestive tracts, reducing their activity and ability to improve soil structure. Furthermore, MPs may contain a certain chemical toxicity, due to the presence of chemical additives (e.g., plasticizers as phthalates, dyes, stabilizers as organotin compounds), which can then be released into the soil and interfere with the physiological and metabolic processes of plants (; ). Alternatively, MPs can act as vectors for pathogenic microorganisms, facilitating their survival and spread in the soil and, consequently, leading to significant reductions in crop yields. Therefore, the presence of MPs can lead, in general, to potentially negative effects on plants, microorganisms, and edaphic invertebrates, compromising soil quality and plant health, potentially affecting agricultural production and food safety (). Recent findings further highlight the role of plants in interacting with environmental MPs not only through root uptake but also via aerial parts. A study by has shown that the absorption and accumulation of airborne MPs by plant leaves occurs widely in the environment, representing an underestimated pathway of exposure. This mechanism should not be overlooked when assessing the risk of MPs exposure for humans and other organisms through the food chain.
In light of the expanding concern, bioremediation techniques to degrade, remove or transform contaminants in soil, water or air into less toxic or harmless compounds are also proposed as an environmentally friendly and sustainable solution to mitigate MPs pollution in soils ().
Microorganisms, in particular bacteria and fungi, play a central role in the degradation, stabilization and removal of MPs in soil, thanks to their ability to metabolize complex compounds and adapt to different environmental conditions (; ). Several studies have explored different potentials offered by specific bacterial genera, such as Pseudomonas, Bacillus and Rhodococcus, which are capable of degrading various types of polymers, including polyethylene (PE), polypropylene (PP) and polystyrene (PS), contributing to the reduction of MPs accumulation in soil (; ). These bacteria produce hydrolytic enzymes that attack polymeric bonds, facilitating the fragmentation of plastic particles and transforming them into simpler, biodegradable compounds (). Similarly, fungi, especially ligninolytic fungi such as Aspergillus and Penicillium, have shown promising abilities to degrade plastic polymers, thanks to the production of extracellular enzymes such as laccase and peroxidase, which both catalyze the breaking of polymer chains (). These enzymes are particularly effective in degrading complex polymers, reducing their mass and modifying their chemical and physical properties. However, the microbial degradation of MPs can be a slow process, influenced by environmental factors such as nutrient availability, temperature and soil pH ().
A promising strategy to optimize the effectiveness of bioremediation is the use of microbial consortia, i.e., communities composed of different bacterial and fungal species working in synergy. These consortia can simultaneously attack different polymeric components, accelerating the degradation of MPs (). For instance, combinations of Bacillus subtilis and Pseudomonas putida have been shown to degrade PE more efficiently than single strains, thanks to a wider range of degrading enzymes produced (). Furthermore, the use of phytodepurative plants, such as Phragmites australis and Typha latifolia, is proving to be an innovative option. These plants can absorb plastic particles through their roots, limiting their dispersion and helping to reduce soil contamination (). The extensive root system of phytodepurators facilitates the contact of MPs with the degrading microorganisms in the soil, thus enhancing the biodegradation process. It has been demonstrated that plants can not only affect the physical degradation of MPs, through interaction with microorganisms in the rhizosphere, but can also act as bioindicators, signaling the presence and concentration of MPs through changes in root growth and development (). For example, it has been observed that high concentrations of MPs in soil can reduce root growth and water and nutrient uptake, negatively affecting plant health and agricultural productivity.
A further enhancer of bioremediation is arbuscular mycorrhizal fungi (AMF), which establish mutualistic symbioses with plant roots, improving nutrient uptake and tolerance to environmental stresses. The AMF have been shown to interact with MPs in the soil, contributing to their degradation through the production of extracellular enzymes and promoting polymer mineralization (). Applying organic soil amendments, such as biochar, could be a valuable aid in improving the efficiency of these enzymatic processes. Biochar, which is derived from the pyrolysis of organic residues, not only increases the stability and activity of microbial enzymes, but also adsorbs MPs, reducing their mobility and prolonging their contact time with the degrading microorganisms (). In addition, using compost enriched with biochar could create a favourable environment for microbial growth, improving the effectiveness of MPs degradation.
Another very innovative approach is the use of algae, in particular microalgae, in the bioremediation of MPs, as discussed by . Microalgae, usually used to treat contaminated water, can also be applied to soils to bioaccumulate MPs. Indeed, thanks to their ability to form biofilms, algae can capture and immobilize plastic particles, thus facilitating their removal from the environment. Although this technique is still in the experimental phase for soil applications, it represents a promising area of research for the future.
4 Concluding remarks
Nature-based Solutions represent a promising and sustainable approach to addressing contemporary environmental and social challenges in urban areas. By exploiting the intrinsic properties of natural ecosystems, NbS provide multiple benefits, including climate change mitigation, biodiversity conservation, and enhanced human wellbeing. The integration of NbS into urban planning, particularly through green infrastructure and bioremediation practices, offers a pathway toward more sustainable and resilient cities while also providing economic and social benefits (see Figure 3). Among the social benefits, civic engagement is arguably the most important output: without shared responsibilities and collective knowledge, it would be impossible to develop and sustain NbS. Also, before implementing an NbS, it is also important to consider the social aspects, including how the stakeholders and citizens could be actively involved in the project.
FIGURE 3
Beyond their role in urban greening, NbS contribute to the bioremediation of contaminated urban soils, offering a sustainable and ecosystem-centered approach in improving soil fertility and restoring ecosystem services. Generic recommendations for bioremediation within the NbS framework include the use of native or climate-resilient plant species, consortia of beneficial microorganisms adapted to local conditions, and the application of organic amendments to support soil microbial activity and structure. Such integrated approaches have shown significant potential in reducing pollutants like heavy metals, hydrocarbons, and MPs, restoring soil functionality and promoting ecological balance. Innovative NbS-aligned proposals might involve the design of multifunctional landscapes that combine remediation approaches with biodiversity enhancement, including constructed wetlands, urban green spaces, or green corridors that incorporate plant species employed in phytoremediation. The use of nature-compatible technologies and monitoring systems can further improve the efficiency of bioremediation.
Despite these advantages, the effectiveness of bioremediation still presents numerous challenges, as it depends on various environmental factors, including pH, temperature, O2 availability, nutrient content, and the chemical-physical diversity of contaminants. In some cases, additional interventions such as biostimulation (e.g., the addition of nutrients to enhance microbial activity) or bioaugmentation (e.g., the introduction of specific microorganisms) may be required to accelerate the degradation process. Furthermore, a deeper understanding of the interactions between contaminants, plants, and microorganisms is needed within the urban context, which is characterized by anthropogenic stresses and variable environmental conditions. Future research should focus on optimizing NbS strategies in urban environments, improving their scalability, and assessing long-term impacts to maximize their effectiveness.
Statements
Author contributions
SCe: Visualization, Writing – original draft, Investigation, Writing – review and editing, Conceptualization. LP: Writing – review and editing, Methodology, Writing – original draft, Investigation. RW: Funding acquisition, Conceptualization, Writing – review and editing. EP: Resources, Writing – review and editing, Funding acquisition, Writing – original draft, Project administration, Conceptualization. SCo: Investigation, Writing – original draft. BB: Writing – review and editing, Methodology. MS: Investigation, Conceptualization, Visualization, Writing – review and editing, Methodology, Writing – original draft.
Funding
The author(s) declare that financial support was received for the research and/or publication of this article. The work was funded from the Horizon Europe scheme under the project “Nature Based Solutions for Soil Management”, Grant agreement ID: 101091246.
Conflict of interest
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.
Generative AI statement
The author(s) declare that no Generative AI was used in the creation of this manuscript.
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Summary
Keywords
ecosystem services, inorganic contaminants, microplastics, organic pollutants, soil remediation, sustainability
Citation
Celletti S, Poreba L, Wawer R, Padoan E, Comis S, Bartosiewicz B and Schiavon M (2025) The potential of nature-based solutions for urban soils: focus on green infrastructure and bioremediation. Front. Environ. Sci. 13:1634662. doi: 10.3389/fenvs.2025.1634662
Received
24 May 2025
Accepted
30 July 2025
Published
15 August 2025
Volume
13 - 2025
Edited by
Chamindra L. Vithana, Southern Cross University, Australia
Reviewed by
Juan Sádaba, University of the Basque Country, Spain
Fan Zhang, Nanjing Forestry University, China
Naji Akbar, Ajman University, United Arab Emirates
Updates
Copyright
© 2025 Celletti, Poreba, Wawer, Padoan, Comis, Bartosiewicz and Schiavon.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Elio Padoan, elio.padoan@unito.it
† These authors share first authorship
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