Abstract Reduced and soil-protective tillage technologies may represent certain negatives for cultivated crops associated with the biomass of mulch from intermediate crops and post-harvest residues. Sown crops, as well as field weeds, are exposed to impaired soil conditions. Soil conditions were assessed using biological tests. Eight plant species were chosen for the tests. Germination of tested plant species took place in controlled conditions in climaboxes. Seeds on Petri dishes were watered with soil leachates from three variants of tillage (Conventional, Minimum tillage, Direct sowing). Soil samples were collected from a 15-year field experiment. The soil leachates inhibited the germination rate of the chosen plant species. In the first term, all species exhibited a lower germination capacity in variants watered with the soil leachate. The reduced tillage technologies can apparently significantly slow down the germination rate in field crops and vegetables. Simple biological tests have the potential to assess the condition of arable soils.

Abstract Both sectors of the Iberian Pyrite Belt, Portuguese and Spanish, have been exploited since ancient times, but more intensively during and after the second half of the 19th century. Large volumes of polymetallic sulfide ore were extracted in open pits or in underground works, processed without environmental concerns, and the generated waste rocks and tailings were simply deposited in the area. Many of these mining sites were abandoned for years under the action of erosive agents, leading to the spread of trace elements and the contamination of soils, waters and sediments.Some of these mine sites have been submitted to rehabilitation actions, mostly using constructive techniques to dig and contain the contaminated tailings and other waste materials, but the remaining soil still needs to be treated with the best available techniques to recover its ecosystem functions.Besides the degraded physical structure and poor nutritional status of these soils, they have common characteristics, as a consequence of the pyrite oxidation and acid drainage produced, such as a high concentration of trace elements and low pH, which must be considered in the remediation plans. This manuscript aims to review the results from studies which have already covered these topics in the Iberian Pyrite Belt, especially in its Portuguese sector, considering: (i) soils’ physicochemical characteristics; (ii) potentially toxic trace elements’ concentration; and (iii) sustainable remediation technologies to cope with this type of soil contamination. Phytostabilization, after the amelioration of the soil’s properties with organic and inorganic amendments, was investigated at the lab and field scale by several authors, and their results were also considered.

Abstract The aim of this study was to determine the extent and patterns of antimony and tin contamination in soils along railway lines, as there are very few data in the literature on this subject.The study was conducted in north-western Croatia. Total and bioavailable concentrations of Sn and Sb were detected using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The following results were obtained: total concentrations of Sb ranged from 0.98 to 52.0 mg/kg and of Sn from 3.04 mg/kg to 97.6 mg/kg. The soil samples showed pronounced Sb and Sn enrichment, up to 87 and 33 times the median value for European soils, respectively. In contrast to the total concentrations, the bioavailable concentrations showed relatively low values. For Sn, the percentage of total content ranged from 0.001 to 0.021%, while for Sb it ranged from 0.001 to 0.136%. Statistical data analysis suggests that the distribution of Sb and Sn in soils near railway lines is influenced by the functional use of the site, distance from the tracks, topography, age of the railway line, and also by soil properties such as soil texture, humus content, and soil pH. This study demonstrates that rail transport is a source of soil pollution with Sn and Sb. The origin of Sb and Sn enrichment is abrasion by brakes, rails, wheels, freight losses, exhaust gasses, etc. Both elements in soils along railway lines pose an environmental risk to humans, agricultural production, and wildlife, and therefore further detailed studies are required.

Abstract Following the BBC’s Blue Planet II nature documentary series on marine ecosystems,plastic packaging has come under public fire, with consumers demanding greener alternatives. The biodegradable properties of some bioplastics have offered a potential solution to the global challenge of plastic pollution, while enabling the capture of food waste through anaerobic digestion as a circular and energy-positive waste treatment strategy. However, despite their increasing popularity, currently bioplastics are being tested in environments that do not reflect real-life waste management scenarios. Bioplastics find their most useful, meaningful and environmentally-sound application in food packaging—why is there so little interest in addressing their anaerobic co-digestion with food waste? Here, we provide a set of recommendations to ensure future studies on bioplastic end-oflife are fit for purpose. This perspective makes the link between the environmental sustainability of bioplastics and the role of food waste anaerobic digestion as we move towards an integrated food–energy–water–waste nexus. It shines light on a novel outlook in the field of bioplastic waste management while uncovering the complexity of a successful path forward. Ultimately, this research strives to ensure that the promotion of bioplastics within a circular economy framework is supported across waste collection and treatment stages.

Abstract The use of post-consumer plastics in concrete production is an ideal alternative to dispose of such wastes while reducing the environmental impacts in terms of pollution and consumption of natural resources and energy. This paper investigates different approaches (i.e., reducing water-to-cement ratio and incorporating steel fibers or polymeric latexes) that compensate for the detrimental effect of waste plastics on the drop in concrete mechanical properties including the bond to embedded steel bars. The polyethylene terephthalate (PET) wastes used in this study were derived from plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete properties are degraded with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The threshold PET volumetric rates are 4.5% and 3% for concrete made using natural or recycled aggregates, respectively. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the concrete performance. The incorporation of 0.8% steel fibers (by volume) or 15% polymers (by mixing water) were appropriate to enhance the bridging phenomena and reduce the propagation of cracks during the pullout loading of steel bars.

Abstract In response to international trends regarding the reduction in plastic waste (or plastic pollution), this work used the official statistics that were recently released, focusing on regulatory actions restricting the use of plastic products and/or the increase in recycling in Taiwan. In addition,the impacts of the COVID-19 pandemic on plastic waste generation and plastic products’ recycling were also addressed in the present study. The results showed that the plastic compositions in the garbage slightly increased in recent years, suggesting that the effect of restrictions on the use of plastic products in Taiwan was not significant, even though the regulatory measures have been implemented since 2002. However, chlorine contents in the garbage were significantly increased in 2020. The increase could be attributed to the fact that kitchen waste (containing salt), household waste containing disinfectant (e.g., chlorine dioxide, sodium hypochlorite) or PVC-made products were generated more during the COVID-19 pandemic. Furthermore, the data also indicated that the monthly quantities of recycled plastic containers and other plastic products had no significant change since January 2020, especially in the outbreak period from May 2021 to July 2021.

Abstract Quietness in an urban environment is vital for the well-being of city residents. Nevertheless, the ambiguity in the conceptualization of the terms noise and quietness as urban acoustic planning and design objectives, has resulted in two different approaches: the soundscape approach and the noise control approach. The main purpose of this research is to supplement the existing approaches by proposing a new ecological acoustics approach in order to identify quiet areas in the city of Mytilene (Lesbos Island, North Aegean, Greece). The use of the soundscape approach involved the participation of Mytilene’s residents and the collection of subjective and objective eligibility criteria. By means of Multi-Criteria Decision Making two urban green areas were highlighted as potential quiet areas. For the noise control approach, road noise maps have been created through a commercial noise mapping software, validated by trough measurements. As a result, two areas located in the outskirts of the city were highlighted. Finally, the novel ecological acoustics approach involved acoustic recordings and the extraction of the Composite Urban Quietness Index (CUQI). The outcome of this approach converged with the soundscape approach results. Quietness, as an urban acoustic planning and design goal, could be viewed as an opportunity for ecologically sustainable urban environments.

Abstract The mismanagement of plastic materials has grown to become a mounting global pollution concern that is closely implicated in unsustainable production and consumption paradigms. The ecological, social, and economic impacts of plastic waste mismanagement are currently transboundary in nature and have necessitated numerous methods of government intervention in order to address and mitigate the globalized and multifaceted dilemmas posed by high rates and volumes of plastic waste generation. This review examines the current landscape of a plastics economy which has operated with a linear momentum, employing large quantities of primary resources and disincentivizing the functioning of a robust recycling market for collecting plastic waste and reintegrating it into the consumer market. This contextualizes an increasing plastic pollution crisis that has required global efforts to address and mitigate the ecological risks and socio-economic challenges of mismanaged plastic waste. A timeline of government interventions regarding plastic pollution is described, including numerous international, regional, and local actions to combat plastic waste, and this is followed by an examination of the relevance of the extended producer responsibility principle to improve plastic waste management and obligate industry to assume responsibility in waste collection and recycling.

Abstract The increase in waste volume and greenhouse gas emissions and decrease in raw-material reserves are some of the serious problems that our planet is facing. The measures needed to address these issues cannot be implemented under the prevailing linear economy model; hence, the circular economy model has been introduced. The successful implementation of circularity, whose basic principles include waste reduction, reuse, and recycling, requires a change in the behaviour of all the parties involved and is expected to lead to industrial–urban symbiosis schemes. The present paper looks at the current state and future prospects of the circular economy in Cyprus, based on the evidence drawn from an EU-funded project entitled “a digital Solid Waste reuse plAtform for BalkaN” (Project Acronym: SWAN). The project’s main objective was the design and development of a digital solid waste reuse platform involving four countries: Greece, Albania, Bulgaria, and Cyprus. Using the data collected, in the context of this project, from a sample of Cypriot industries, we looked into the familiarisation of the respondents with the basic concepts of circularity and their willingness to participate in symbiotic value chains. Moreover, we examined the composition of the waste streams produced by those industries and proposed potential waste reuse business models and subsequent symbiotic clusters.

Abstract The continuous expansion in the textile industry results in high loads of coloured wastewaters that heavily pollute the limited freshwater sources. Therefore, a wide array of treatment methods has been used to remediate water/wastewater from dyes. One common practice is the use of plants to degrade, absorb, metabolise, and detoxify different types of pollutants, including dyes. This study employs sweet basil (Ocimum basilicum) as a phytoremediation model herb to remove different concentrations (5–25 mg/L) of methylene blue (MB) dye from synthetic water, taking into account the effects of the MB dye concentration (5–25 mg/L) and contact time (up to 10 days). The results showed that the ability of Ocimum basilicum to absorb MB dye decreased with the increase of the MB dye concentration and increased with the increase of the contact time. The best removal of the MB dye was 93% when the concentration of the MB dye was 25 mg/L and the contact time was 10 days. Additionally, it was noticed that the relative growth rate (RGR) of the herbs was adversely influenced by increasing MB dye concentrations and that the best RGR value was 2.2 g/day when the MB dye concentration was 5 mg/L.

Abstract Pollution from numerous contaminants due to many anthropogenic activities affects soils quality. Industrialized countries have many contaminated sites; their remediation is a priority in environmental legislation. The aim of this overview is to consider the evolution of soil remediation from consolidated invasive technologies to environmentally friendly green strategies. The selection of technology is no longer exclusively based on eliminating the source of pollution but aims at remediation, which includes the recovery of soil quality. “Green remediation” appears to be the key to addressing the issue of remediation of contaminated sites as it focuses on environmental quality,including the preservation of the environment. Further developments in green remediation reflect the aim of promoting clean-up strategies that also address the effects of climate change. Sustainable and resilient remediation faces the environmental challenge of achieving targets while reducing the environmental damage caused by clean-up interventions and must involve an awareness that social systems and environmental systems are closely connected.

Abstract The contamination of areas around solid urban waste dumps is a global challenge for the maintenance of environmental quality in large urban centres in developing countries. This study applied a geophysical method (electrical resistivity) to identify leachate contamination plumes in the subsoil and groundwater, as well as to describe their temporal dynamics (2020 and 2021) in the surroundings of the Hulene-B waste dump, Maputo, Mozambique. Eight 400 m electrical resistivity profiles were performed, four profiles in January 2020 and four profiles in May 2021 overlapped, and the data were inverted with RES2D software. The electrical resistivity models predominantly indicate an E-W movement of large contamination plumes that are successively diluted with saturated media and groundwater, creating zones of less resistive anomalies (<4.2–8.5 Ω·m) possibly contaminated at the two analysed seasons, between 2020–2021. The thickness of the contamination plumes was higher in summer (2020) for profiles 1 and 2, and we associate it with the production and migration mechanisms of leachate that are intense in the hot and rainy season. Southwest of the dump, profile 4b showed the propagation of anomalous areas on the surface and at depth, which are associated with the production of leachate resulting from the continuous decomposition of waste that is continuously deposited in a new area southwest of the dump, thus generating a slow and continuous migration of leachate at depth, mainly in winter (2021). The spatial distribution of contamination plumes during both seasons was reduced significantly farther away from the waste deposit, revealing the attenuating effect of groundwater and lithological substrate (Profile 3).

Abstract Mineral processing and metallurgy production centers may leave a far-reaching fingerprint of soil contamination. This scenario is particularly relevant in the mining district of Linares (Southern Spain), where former industrial sites are now dedicated to other land uses. Within this context,we selected five sectors of concern in Linares region, which are currently used as agricultural and residential areas. The study began with an edaphic characterization, including grain-size fractioning and soil chemical analyses, which were complemented by mineralogical and sequential extraction information. Anomalous soil concentrations of As, Cd, Cu, Pb, and Zn were found, with higher values than the admissible regional guideline limits. Moreover, chemical speciation indicated that in general, Pb, Zn, and Cd were highly available and bound mainly to the carbonate fraction. In addition, health risk assessment evidenced potential threats by Pb and As. Regarding remediation approaches, we observed that, in soils affected by mining and ore dressing activities, the clay and silt size fractions contained the highest pollution load, making them suitable for a size classification treatment. By contrast, in areas affected by metallurgical activity, pollutants were prone to be evenly distributed among all grain sizes, thereby complicating the implementation of such remediation strategies.

Abstract Polycyclic aromatic hydrocarbons (PAHs) form a convenient structural series of molecules with which to examine the selectivity exerted on their removal by soil microbiota. It is known that there is an inverse relationship between PAH molecular size and degradation rates in soil. In this paper, we look at how the magnitude of the slope for this relationship, m, can be used as an indicator of the effect of metal co-contaminants on degradation rates across a range of PAH molecular weights. The analysis utilises data collected from our previous microcosm study (Deary, M.E.; Ekumankama, C.C.; Cummings, S.P. Development of a novel kinetic model for the analysis of PAH biodegradation in the presence of lead and cadmium co-contaminants. Journal of Hazard Materials 2016, 307, 240–252) in which we followed the degradation of the 16 US EPA PAHs over 40 weeks in soil microcosms taken from a high organic matter content woodland soil. The soil was amended with a PAH mixture (total concentration of 2166 mg kg−1) and with a range of metal co-contaminant concentrations (lead,up to 782 mg kg−1; cadmium up to 620 mg kg−1; and mercury up to 1150 mg kg−1). It was found that the magnitude of m increases in relation to the applied concentration of metal co-contaminant ,indicating a more adverse effect on microbial communities that participate in the removal of higher molecular weight PAHs. We conclude that m is a useful parameter by which we might measure the differential effects of environmental contaminants on the PAH removal. Such information will be useful in planning and implementing remediation strategies.

Abstract A river is an ecosystem where fish fauna represents an important structural element. To re-establish connectivity, it is imperative to allow movement between functional habitats. Due to the hydromorphological complexity of large anthropized rivers and the lack of study techniques that can be used in such environments, relevant data with regard to fish ecology are scarce. On the River Meuse, Belgium, at a point 323 km upstream from the North Sea, the Lixhe hydroelectric dam is equipped with two fishways. Both were continuously monitored using capture traps for 20 consecutive years (from 1999 to 2018), representing 4151 monitoring events. The objectives of the present study were to describe the overall abundance and movement indicators of mainly holobiotic potamodromous fish species and to analyse their temporal evolution. We captured 388,631 individuals (n = 35 fish species) during the 20 years of fishway monitoring; 22.7% were adults (>75% of which were cyprinids), and 83.3% juveniles (>90% cyprinids). From 1999 to 2018, the results showed a drastic reduction in yearly captures for some native species as well as the apparent emergence of non-native (e.g., Silurus glanis) and reintroduced species (e.g., Salmo salar). The annual capture periodicities associated with environmental factors were clearly defined and were mostly related to the spring spawning migration of the adult stage. This long-term monitoring demonstrated how the fishways are used by the whole fish community and allowed a better understanding of their movement ecology in a large lowland anthropized river. The appearance of non-native species and the drastic decline in abundance of some common and widespread European fish should prompt river managers to adopt conservation measures.

Abstract The increasing presence of nanomaterials in consumer products has led the scientific community to study the environmental fate of these contaminants of emerging concern. Silver nanoparticles, used mainly for their antibacterial properties, are among the most common nanomaterials. Understanding their transformations and interactions with living organisms, especially under environmentally relevant conditions that can modify metal bioavailability, is a crucial step in the study of their impacts on aquatic ecosystems. In the present study, citrate-coated silver nanoparticles (20 nm; 10 µg/L) were added to the surface freshwater layer of mesocosms simulating a stratified estuary. The investigation by dialysis of the nanoparticle dissolution showed that a large amount of total silver was found in the freshwater layer (and a very low amount in the seawater layer) and that 5–15% was in the form of dissolved silver. These results indicate that the halocline, separating fresh water from seawater, acted as a strong density barrier limiting the sedimentation of the nanoparticles. A simple trophic chain, composed of the freshwater alga hlamydomonas reinhardtii and the invertebrate Daphnia magna, was used to determine silver bioavailability. This study suggests that citrate-coated silver nanoparticles do not significantly contribute to Ag accumulation by algae but may do so for invertebrates.