Environments, Volume 11, Issue 2 (February 2024) – 14 articles

Ecosystem functioning depends on complex interactions between microorganisms, hosts, and the environment. Changes in environmental conditions (e.g., ocean acidification) in combination with anthropogenic pollution have been shown to affect the composition and function of free-living microbial communities, but little is known about the effects these stressors on host-associated communities. This study aims to characterize the response of host-associated bacterial communities of the bottom-dwelling polychaete Hediste diversicolor and the epibenthic gastropod Peringia ulvae to oil contamination and reduced seawater pH. The independent and interactive effects of both stressors were simulated under controlled conditions. The response of host-associated bacterial communities was assessed using the high-throughput sequencing of the 16S rRNA gene and several biochemical markers related to host metabolic pathways, e.g., neurotransmission, anaerobic metabolism, biotransformation, oxidative stress, and energy consumption. In H. diversicolor, reduced seawater pH was associated with a high relative abundance of Cyanobacteria, while in P. ulvae oil contamination was associated with a reduction in the relative abundance of Chitinophagales. In P. ulvae, enrichment with oil hydrocarbon-degrading bacteria suggests a possible role of these organisms in the dispersion of oil hydrocarbon degraders. Furthermore, oil supplementation shifted some specific biochemical markers of gastropods related to oxidative stress and energy consumption, which suggests host stress. In general, the bacterial communities and biochemical markers of the gastropod were more affected by stressors than those of the polychaete. Overall, this study contributes to a better understanding of the response of host-associated bacterial communities of benthic macrofauna to anthropogenic contamination and environmental change. Full article

This paper focuses on using a novel approach to assess the statistical variability of management data from an aerobic thermophilic biological plant (AWTP) utilizing a fluidized bed biological reactor. A proper statistical characterization of full-scale thermophilic biological systems, in fact, may inform process optimization in the light of a future automation of treatment plants. We present a case study that spans the period from 2018 to 2023 and encompasses various high-strength aqueous waste (AW) in continuous mode. Key aspects of the proposed analytical approach include: (i) utilizing advanced descriptive statistics, such as violin graphs, to depict the variability of monitored parameters over five years; (ii) conducting correlation analyses (Spearman and Pearson correlation matrices) specifically focusing on nitrogenous forms within the AW; (iii) applying multivariate statistical analysis to assess the correlation between pollutants released and the plant’s energy and oxygen consumption; and (iv) reconstructing parameter trends by considering periodic and random components, thus enhancing the understanding of the system’s behavior over time. The findings presented in this paper offer valuable insights into the performance and optimization of AWTPs, potentially leading to a proper planning of the loads and consequent feeding of the plants. If properly enacted, our approach may provide a significant contribution to the field of aqueous waste management. Full article

Constructed wetland systems (CWs) are technologies based on natural processes for pollutant removal and have been more and more accepted in the treatment of domestic and industrial wastewater. This study selected and reviewed articles published in the last six years involving the use of different CW conceptions and their association with other technologies to treat different effluents and evaluated the quality of the effluents for reuse. From a total of 81 articles reviewed, 41 presented quantitative data on the quality of the treated effluent in relation to the requirements of the reuse regulations in different countries of the world. CWs can be used to treat gray water and runoff water, as well as domestic and industrial effluents with the purpose of reusing them. While studies on the removal of new chemical and biological substances have increased, challenges are associated with the optimization of CWs to improve the removal of pathogens and new contaminants that have appeared more recently. The potential for the improved removal of those pollutants lies in the association of CWs with conventional and advanced technologies in new configurations. We concluded that studies related to the reuse of effluents using CWs are in constant evolution, with experiments at different scales. The perspectives are promising since CWs are an economic, environmentally friendly, and efficient technology to help in the mitigation of water scarcity problems imposed by climate changes. Full article

Urban agricultural soils have important social, environmental, and economic roles in big cities, contributing to their sustainability. However, food production in urban soils may be compromised due to soil pollution that resulted from decades of industrial, non-regulated environmental activity and mobile transport. In this study, 12 soils from the urban agricultural area of Rome (Italy) were analyzed for the potentially toxic elements (PTEs) Be, Ba, Pb, Co, Ni, V, Zn, Hg, Cd, As, Cu, and Cr. All but one of the soils under analysis were characterized by at least one PTE concentration above the threshold limit defined by the D.Lgs 152/06 for agricultural soils. Multivariate analysis showed that the soils could be classified into five clusters: clusters I and II had relatively lower mean PTE concentrations; clusters III, IV, and V had relatively higher mean PTE concentrations with several PTE concentrations above the threshold proposed by ILD. Three factors contributing to the variability of the PTE’s concentration in the soils under investigation were identified: a geological factor related to PTE As, Ba, Be, and V; an anthropogenic factor related to Pb and Cu; and a mixed factor related to Co, Cr, Ni, and Zn. High PTE content may limit the utilization of urban soils for food production. Full article

Purely natural land formations are increasingly rare in today’s world, as most areas have been shaped, to varying degrees, by human influence over time. To better understand ongoing changes in the natural environment, we adopted an approach that involves identifying global systems with a significant anthropogenic component. In this study, we developed a new classification of Global Environmental Systems based on over 20 high-resolution datasets, covering abiotic, biotic, and anthropogenic conditions. We created abiotic, biotic, and anthropogenic classifications, each with ten classes. The combinations of these classes result in 169 distinct classes of Global Environmental Systems. This classification provides a suitable spatial framework for monitoring land use dynamics, biodiversity changes, global climate change impacts, and various processes exhibiting complex spatial patterns. Full article

Coal remains an important fuel for use in thermal power plants. However, coal-burning power plants produce large amounts of CFA, which contains TEs such as B, F, and Se, which are leached upon contact with water and act as potential polluters of aquifer systems and soil. To study the transformation of TEs, a thermodynamic calculation (FactSage 7.2) was used. Paper sludge ash was used as a calcium compound additive. The influence of blending a high-calcium additive on the environmental safety of TEs was investigated based on the effect of the mass addition ratio of PS ash. This study’s results confirmed that the leaching processes of TEs, namely (CaO)₂(Al₂O₃), CaF₂, Ca₁₀(PO₄)F₂, and CaSeO₄(H₂O)₂, were caused by the formation of B, F, and Se compounds during the leaching process. Thus, it is clear that calcium has the greatest influence on the transformation of TEs due to their reaction, which, in turn, minimizes the effects of the TEs’ release into the environment. The concentrations of TEs from the sample and addition of PS ash decreased slightly, indicating that the inhibition of TEs was enabled through the addition of PS ash. Although the PS ash YB had the highest calcium content, the PS ash YC gave the best results during the B and Se inhibition processes. The experimental observation was also evaluated for comparison. For the analysis of TEs’ leaching ratios using the thermodynamic calculation and experiment, the experimental results were lower than those initially predicted. These results will help us to choose the best available control technology to minimize the effects of TEs released into the environment. Full article

BioWin 6.0 does not accurately predict phosphorus (P) speciation in acidogenic anaerobic digesters under default kinetics characterization and parameterization. The accurate modeling of acid-phase digestion is needed to predict the performance of novel nutrient recovery technologies that act on these digester effluents. The main thrust of this work was to identify and correct the causes of inaccurate P partitioning and precipitation within BioWin models of acid-phase digestion reactors. A BioWin configuration including an organic acid digester was parameterized and recalibrated based on the known traits of acid-phase digestion and then validated against a full-scale digester in a municipal wastewater treatment plant. This digester, with pH 5.14 and 61–74% solubilized P, was predicted by BioWin default parameters to have only 27% soluble P and a net formation of P precipitates. Corrections to the polyphosphate-accumulating organism decay, endogenous product decay, hydrolysis rate, and brushite behavior resulted in 67% solubilization with no precipitate formation. Cabinet configurations showed similar behavior when modified to include an acid-phase digester under default parameters, but predictions were similarly amended by our parameter changes. This improved modeling technique should allow operators to effectively characterize acid digesters for their own treatment trains and allow engineers to predict the performance of novel nutrient recovery technologies acting on acidogenic digest. Full article

Microplastics resulting from the fragmentation of plastics in electronic waste (e-waste) are an emerging but understudied environmental concern. This systematic review employs a Driver–Pressure–State–Impact–Response (DPSIR) framework to investigate the sources, prevalence, and environmental effects of e-waste microplastics, identifying knowledge gaps. The available literature on e-waste microplastics was retrieved from Scopus and Web of Science (n = 24), and trends in electrical and electronic equipment were retrieved from European Union databases. The growing incorporation of electronics into daily life results in a global annual growth rate of 3–4% for e-waste, of which only 17.4% is collected for recycling. E-waste microplastics are frequently found in soils near disposal or disassembly facilities, potentially leaching hazardous metals (e.g., Pb) or organic compounds (e.g., flame retardants). These microplastics contaminate the food chain and can have adverse effects on the soil and gut microbiome, organisms, and human health, either independently or associated with other chemicals. Responses include the implementation of regulations, improvement of waste management systems, and mitigation measures. Despite these concerns, the literature on the topic remains limited, emphasizing the need for additional research on the identification of e-waste microplastics and their toxicity. Full article

In semiarid environments, vine cultivation is a land use with a high impact with regard to soil erosion, loss of organic matter and biodiversity, contamination, and compaction. In addition, the wine supply chain produces a considerable quantity of organic waste, which remains as residues in the ecosystem. Within this context, we developed a sustainable vine management system to improve the efficient use of fertilisers by applying a by-product derived from the composting of winery wastes and zeolite. We evaluated the effects of the zeolite-based compost on the chemical, physical, and biochemical soil properties of a productive vineyard. Four treatments were set up and monitored for about two years. These were as follows: (1) Commercial compost (COM); (2) Zeolite (Z); (3) 30% zeolite and 70% winery waste compost (30 ZEO); (4) 10% zeolite and 90% winery waste compost (10 ZEO). The results demonstrated that the ZEO treatments could be considered a win–win solution able to improve soil water content, nutrient retention, carbon sequestration, and biochemical activity while also recycling wastes. In particular, 10 ZEO seems to be the amendment that best combines an improvement in soil biochemical properties with gradual and constant nutrient availability, thus satisfying, without exceeding, soil and plant needs. Full article

Timely release of flow from upstream hydropower generation facilities on the Peace River can enhance potential ice-jam flooding near the drying Peace–Athabasca Delta (PAD), a Ramsar wetland of international importance and homeland to Indigenous Peoples. An important consideration in deciding whether and when to commence a release is the celerity of the breakup front as it advances along the Peace River. Relevant historical data for a key stretch of the river are analyzed to determine average celerities, which can vary by an order of magnitude from year to year. Seven breakup events are identified that might have been candidates for a release, and the predictability of associated celerities is explored in terms of antecedent hydroclimatic variables, including cumulative winter snowfall, snow water equivalent on 1 April, ice cover thickness, coldness of the winter, and freezeup level. It is shown that celerity can be predicted to within a factor of two or less, with the freezeup level giving the best results. Three of the seven “promising” events culminated in PAD floods and were associated with the three highest celerities. The empirical findings are shown to generally align with physical understanding of breakup driving and resisting factors. Full article

The foremost priority of the Sendai Framework for Disaster Risk Reduction (SFDRR) is the increased understanding of disaster risk and strengthening its management. Detailed insights into African disaster risk drivers and assessment of policies for Disaster Risk Reduction (DRR) are sparse, hence this study. Using the Index for Risk Management (INFORM) data for 2022, this study determines important disaster risk drivers in Africa using a random forest machine learning model. Violent conflicts, current and projected, emerge as the only hazard factor significantly predictive of disaster risk in Africa, from the analyzed data. Other factors are mostly the sub-components of lack of coping capacity. Furthermore, 25 policies of the 10 countries of very high disaster risk were analyzed to evaluate their inclusion of pre-identified disaster risk factors. The findings of this study depart from the viewpoint of giving natural hazards greater attention in African disaster risk literature. Moreover, identified disaster risk drivers in Africa coincide with the social dimension of disasters, and broader continental developmental and policy issues. As Africa grapples with the complex interplay of environmental, socioeconomic, and conflict-related factors shaping disaster risk, the imperative arises for the development and implementation of comprehensive policies aimed at poverty and vulnerability-reduction to foster resilience across the region. Full article

Tungsten is an essential element for many cutting-edge industries. Its use is increasing, so much that it has become a “critical element”. With the increase in the use of tungsten, a possible increase in its presence in environmental matrices including soil is expected. In this research, we assessed the environmental availability and bioaccessibility of W in relation to soil properties. Four representative Mediterranean soils, collected in Italy, were spiked with tungsten and incubated for 12 months. In the spiked soils, the environmental availability of the element was determined by the Wenzel sequential extractions. The bioaccessibility was determined by the UBM (BARGE) method in both the gastric and intestinal phases. The findings indicated that the environmental availability is largely influenced by soil properties such as pH and organic matter, while a lower influence was discovered for bioaccessibility, particularly for the gastric phase. These differences could be ascribed to the characteristics of the extractants utilized in the various tests, in particular the pH values. These results could be a valuable reference to integrate with studies on really and not spiked contaminated soils, for the improvement of risk assessments and the development of strategies for remediating soils polluted with tungsten. Full article

The recycling and proper management of PET bottles is needed to avoid plastic pollution, as well as to achieve a plastic circular economy. In this study, we examined the recycling system of PET bottles and their material flows by life cycle, from production to recycling and disposal under different scenarios with reduced consumption for PET bottles. In Korea, PET bottle recycling has been managed by the extended producer responsibility system since 2003. As of 2021, annual usage of PET bottles per capita in Korea was estimated to be approximately 6.5 kg. The recycling rate of PET bottles after collection was determined to be 79% in 2021. However, recycled PET (or r-PET) from mechanical recycling is mostly used in low-grade PET applications such as short fibers, bands, and sheets. More than 112 thousand tons of r-PET chips would be needed to meet the 30% recycled content requirement in PET bottles in 2030 by regulation. Thus, there is an urgent need for high-quality secondary raw materials (i.e., food-grade) by adopting advanced sorting and recycling technologies for PET bottles with recycled content. PET bottle-to-bottle recycling practices can ensure the production of high-quality recycled materials and move Korea toward a plastic circular economy. Full article

The rare earth elements (REE) comprise a group of 16 chemically very similar elements that occur widespread in rocks, soils, and water bodies, share similar ionic radii to the essential element Ca²⁺, and consequently also occur in biota. Given that REE form mainly trivalent cations, they also share similarities to Al³⁺. Compared to their chemical cognate Ca, they have a higher reactivity. Thus, their accumulation in soils may constitute a severe environmental threat. Over the last decades, the increasing use of REE in modern technology and fertilizers raised concerns about the pollution of soils and water bodies, which led to a rapidly increasing number of publications dealing with REE toxicity to plants, animals and humans, the fate of REE in soil–plant systems, REE cycling in ecosystems and impacts of REE pollution on food security. This review aims to give an overview of the current knowledge on the occurrence of REE in the total environment, including relevant environmental processes governing their mobility, chemical speciation and transfer from abiotic compartments into biota. Beginning with an overview of analytical approaches, we summarize the current knowledge on the ecology of REE in the lithosphere, pedosphere, hydrosphere and biosphere, including impacts of soil pollution on food security and public health. Full article