Search Results (1,008)

Wastewater treatment plants (WWTP) play a critical role in mitigating adverse environmental impacts of urban and industrial wastewater by removing pollutants and reducing the risk of contamination. Discharges of treated effluents from WWTPs can still have significant effects on freshwater ecosystems, particularly on sensitive species like brown trout. We analyzed the effects of a modern WWTP on a freshwater ecosystem, studying fish biodiversity and biomass, the occurrence of the parasitic disease Proliferative Kidney Disease (PKD) on brown trout, river water temperatures throughout the year and fish habitat and diversity. No major differences between up- and downstream of the WWTP were observed in habitat structure and attractiveness, fish biomass and species diversity, nor in PKD prevalence or intermediate host presence. However, immediately at the WWTP’s effluent and continuing downstream, the water temperature rose by almost 1 °C. While WWTPs are crucial for reducing the environmental impact of urban and industrial wastewater, their effluents can still have important consequences for freshwater ecosystems. Brown trout are particularly susceptible to increases in water temperature, especially regarding PKD severity and consequent mortality. To ensure the long-term health and sustainability of freshwater ecosystems, it is imperative to improve measures to minimize water temperature rises and mitigate downstream cascade effects on sensitive organisms like brown trout. Full article

A comprehensive hydrogeochemical survey of the geothermal waters from the Nappe Zone (Maghrebides fold-and-thrust belt) was undertaken to determine the origins of geothermal waters and to assess the health risks associated with their potentially toxic elements. A total of 11 geothermal water and 3 stream water samples were collected and analysed for major and trace elements (As, B, Ba, Fe, Mn, Pb, Sr, Zn). Two main geothermal water groups were highlighted by hydrogeochemical diagrams and multivariate analyses (PCA, HCA): the first group is the Na−Cl type, TDS > 10 g/L, controlled by deep circulation, while the second group is the Na-Cl−HCO₃ type, TDS < 2 g/L, and controlled by shallow circulation. A curved hydrogeochemical evolution path, observed from mixed bicarbonate shallow groundwater to chloride geothermal water, indicates that the interaction with evaporites drives the chemistry of the geothermal samples. On these, the As enrichments come from sulphide oxidation polymetallic mineralisation during the upwelling to the surface from E–W major lineaments. Therefore, E–W lineaments are potential areas for mineral prospecting. The health risk assessment reveals that the concentration of potentially toxic elements in geothermal waters are lower than the guideline values for the protection of freshwater aquatic life and dermal exposure (bathing or balneology). Full article

Agricultural soils close to mining establishments may suffer from airborne pollution, due to excavation and transportation activities. To assess the impact of soil pollution from potentially toxic elements (PTEs) on soil and human health in agricultural areas close to Fe-Ni mines, 36 composite topsoil samples were collected from central Euboea Island, Greece. The soils were analyzed for their physicochemical properties and for total and bioavailable Ni, Cr, Co, Mn, Fe, Pb, Cu, and Zn concentrations; the BCR sequential extraction protocol was additionally applied to all samples. Soil enrichment caused by the metals and the implications of soil degradation on the ecosystem were evaluated using the calculation of single pollution indices (PI) and the potential ecological risk index (RI), respectively. The hazard index (HI) for non-carcinogenic metals and life cancer risk (LCR) for carcinogenic metals were used to appraise the human health risks. Extremely high, very high, and considerably high total concentrations of Ni, Cr, and Mn, respectively, were determined. Though most of the total amounts of metals in soil samples were found to be related to the residual fraction, the considerable portion extracted in the first two steps of the BCR process can be regarded as able to introduce toxicity issues in the local biota. High PI values of Cr, Co, and especially Ni point to severely polluted soils, and the mean RI values indicate a considerable risk for biota. HI values > 1 show increased possibilities for non-carcinogenic health issues in children, whereas the LCR values of Ni were above the critical limit, 1 × 10⁻⁴, for both children and adults. Full article

The study analyses the possible valorisation of lake sediments for sustainable mortar, in accordance with the principles of the circular economy, to obtain a sustainable material, since reuse occurs without any kind of preliminary treatment and preserves the consumption of virgin raw materials in the mix design. Moreover, it reduces the amount of water to be used in the mix since part of it is already contained in the sediments. The research was performed on sediments dredged from two artificial reservoirs, Camastra and San Giuliano, located in Basilicata, a region in southern Italy. Cement mortar was prepared by completely replacing, at different quantities, the fine aggregate and, for some of it, partially replacing, at a constant quantity, part of the binder. Workability, mechanical strength, and density were measured, as well as the possible release of contaminants. The investigations made it possible to assess the influence of replacing aggregate with sediment on mortar performance, showing that San Giuliano sediment produces mortar with great workability (~140%), comparable to that of normalised mortar. Similarly, the mechanical strengths of some specimens (SG_s1 and SG_s2) were approximately 60 MPa and 52 MPa, respectively (about 15% higher than that of normalised mortar). On the contrary, for the mortar prepared with the Camastra sediments, both workability and mechanical strength were ~50% lower than normalised mortar. Furthermore, the leaching test did not reveal contaminant release. Full article

Conventional methods to analyze biochemical processes related to contaminant toxicity usually require the sacrifice of animals to collect tissues and organs. However, for ethical reasons and especially for endangered species, non- or minimal-invasive methods should be preferred. Among vertebrates, reptiles show a general decline worldwide and therefore the use of non- or minimal-invasive methods to measure some biochemical processes in these animals are encouraged. It is well known that most lizards use a common safety behavior implying the natural loss of tail in the case of predation events. Therefore, if common analyses testing contaminant toxicity could be performed in tail tissue, this method, not implying the sacrifice of the animals, could be considered as a good minimal-invasive method. The aim of this study is to test on wild Italian wall lizard Podarcis siculus the use of tail to detect a large set of biomarkers including oxidative stress (TOSCAROO, TOSCAOH, CAT, tGSH, MDA), biotransformation processes (EROD, GSTs) and neurotoxicity (AChE, BChE). All the biochemical responses, excluding EROD and MDA, resulted to be analytically detectable in tail tissues of P. siculus, although the mean values obtained with this minimal-invasive method were significantly lower than those obtained with invasive one. Full article

The development of efficient heterogeneous persulfate activators is one of the main research topics in the wastewater treatment area. The present work deals with the heterogeneous activation of sodium persulfate (SPS) using nickel oxide/strontium carbonate (NiO/SrCO₃) for the degradation of sulfamethoxazole (SMX), a representative compound from the group of antibiotics. Results showed that NiO/SrCO₃ exhibited high performance towards the activation of SPS, leading to SMX elimination in brief time spans. The impact of SPS (25–100 mg/L), NiO/SrCO₃ (50–250 mg/L), and SMX (0.25–3.00 mg/L) concentration, and initial pH on the decomposition of SMX was further examined. Experiments were also conducted in real matrices such as secondary effluent and bottled water, revealing the existence of retarding phenomena compared to ultrapure water. This behavior was further investigated with the addition of bicarbonates, chlorides, or humic acid in ultrapure water. It was found that organic matter significantly hampered SMX removal. The role of the main radicals (hydroxyl and sulfate radicals) was determined using appropriate radical traps (methanol and tert-butanol). These quenching experiments combined with the conducted electrochemical measurements revealed that both a radical and a non-radical mechanism contribute to the decomposition of SMX. Full article

Recently, due to rapid industrialization and urbanization, many studies have focused on the assessment of soil metal contamination. The present research aimed to investigate the concentration of potentially hazardous elements (Al, Cr, Cu, Fe, Mg, Mn, Ni, Pb, V and Zn) in three different areas (forest, wildfire forest and urban) of the Mediterranean region. Contamination levels were further assessed calculating different indices: contamination factor (CF), geo-accumulation index (GI) and ecological risk (E). The results showed high concentrations of V, Mg and Mn in forest and wildfire forest soils, as well as high concentrations of Al, Fe, Ni, Pb and Zn in urban soils. According to the contamination indices, Pb exceeded the background level in both wildfire forest and urban soils. According to human risk assessment, inhalation appeared the main route of exposure of metals in soils, especially for children. The overall cancer risk was higher than the safe level, especially for Pb. Different relationships were found between the contamination indices and the potential risk of carcinogenic effects according to the diverse metal concentrations. Particularly, wildfire soils showed human health risks mainly linked to Pb, Cu and Cr contaminations, due to human activities, and Ni, due to both anthropogenic and pedogenetic input. Instead, the urban soils showed that Zn contamination, mainly related to urban traffic, influenced the potential carcinogenetic risk in this area. The carcinogenic risk was higher than acceptable values for all the metals assessed. These findings highlighted the need to develop further management practices to protect soils from metal pollution and reduce human health risks. Full article

Birds are commonly used as bioindicators, and their feathers are considered suitable tissues for assessing the presence of contaminants, such as trace elements, in the environment. In agroecosystems, trace elements’ occurrence can be associated with both natural and anthropogenic processes, including vehicular traffic, traditional fertilizers, food feed additives for livestock, and the use of sewage sludge as fertilizer. Here, we evaluated the concentrations of twelve trace elements (Aluminium, Arsenic, Cadmium, Chromium, Copper, Iron, Mercury, Manganese, Nickel, Lead, Selenium, and Zinc) in the feathers of barn swallow (Hirundo rustica) nestlings. We then compared the concentrations of these elements between nestlings grown in areas amended or not amended with sewage sludge in 2019 and 2020 in a broad region of the Po Plain (Northern Italy). Multivariate analysis showed that the element content of the feathers significantly differed among years and areas, suggesting that the concentration of nestlings’ feathers may indicate the local level of contamination. However, univariate analyses did not show clear spatial differences, possibly due to co-occurring sources of trace elements other than sewage sludge. These results suggest that barn swallow nestlings can be a reliable sentinel for the monitoring of local variation of the environmental occurrence of trace elements. Full article

Although beef production is one of the most valuable drivers of the global livestock economy, it is considered the main contributor to GHG emissions derived from livestock. This study’s objectives were to estimate the GHG emissions (expressed in carbon dioxide equivalents; CO₂-eq) from the beef sector in Greece at the national and prefecture levels during the period 2011–2021 and to explore potential mitigation scenarios. The Tier 1 and 2 methodologies were implemented to estimate the GHG emissions. The total estimated emissions increased over the study period. Although both methodologies captured similar trends in the changes in GHG emissions, the Tier 2 estimations revealed lower emissions and fluctuations due to the different and more precise computational approaches. At the prefecture level, fluctuations in emissions were also noted. However, specific regions showed higher increases in emissions. The observed increase in emissions, in terms of either absolute values (Gg CO₂-eq) or intensities (Kg CO₂-eq/Kg produced beef carcass), is of utmost importance, and further mitigation strategies should be considered. The regression analysis showed a good predictive ability for emissions, using the number of livestock animals as the input. The equations derived from this analysis could be further used as first-approach tools for capturing future emissions at the national level before proceeding with more elaborate approaches. The different scenarios examined in response to the sector’s challenges showed moderate changes in GHG emissions. Depending on national priorities, such scenarios could serve as pilot case studies, which may assist stakeholders in improving the sustainability of the sector in the future. Full article

Freshwater reservoirs constitute an important source of drinking water, but eutrophication and higher temperatures increase the risk of more frequent blooms of cyanobacteria, including species that produce toxins. To improve the prediction of cyanotoxin episodes, we studied the annual occurrence of potential microcystin (MC) and saxitoxin (STX)-producing cyanobacteria in the Lobo reservoir, São Paulo State, Brazil. Relationships among environmental variables, cyanobacterial biomass, numbers of the mcyE and sxtA genotypes (genes encoding production of MC and STX, respectively), and concentrations of MC and STX were determined to address variables applicable for monitoring and predicting the dynamics of cyanobacteria and cyanotoxins in the reservoir. Microscopy confirmed the presence of potentially toxin-producing cyanobacteria at all sampling times, and qPCR detection showed the occurrence of both mcyE and sxtA in most samples. Concentrations of MC and STX were generally low (MC 0–1.54 µg L⁻¹; STX 0.03–0.21 µg L⁻¹). The highest MC level exceeded the recommended limit for human intake of 1 µg L⁻¹. The abundance of the mcyE and sxtA genes, as well as the toxin concentrations, were positively correlated with the biomass of Phormidium and Raphidiopsis. Among environmental variables, the abundance of potential toxic cyanobacteria was mainly affected by P limitation (high TN:TP ratios). Our data show that detection of the mcyE and sxtA genotypes serves as a useful and reliable predictor of toxin episodes but might be combined with chemical toxin detection to form an environmental toolbox for cyanotoxin monitoring. Full article

Waste-grade cork samples of Quercus cerris were subjected to maceration extraction using 7 different solvents, including pure water (I), pure acetone (II), 75% aqueous ethanol (III), 75% aqueous methanol (IV), 75% aqueous acetone (V), 50% aqueous acetone (VI), and 25% aqueous acetone (VII). The extract yields, extract compositions, as well as antioxidant and antimicrobial activities of the extracts were analyzed. The results showed that maceration extraction was highly efficient, particularly with binary solvents resulting in up to 6% extract yield and up to 488 mg GAE/g extract total phenolic content. The extracts exhibited a variable antioxidant activity determined by DPPH and FRAP methods as well as antimicrobial activity against gram-positive bacteria and fungus determined by agar diffusion test. The CIELAB color parameters of extracts were correlated with maceration time, and the correlation was highest with pure water extracts. The FT-IR spectra of acetone-extracted cork revealed six key markers of phenolic compounds with the presence of peaks at approximately 2920 cm⁻¹, 2850 cm⁻¹, 1609 cm⁻¹, 1517 cm⁻¹, 1277 cm⁻¹, and 1114 cm⁻¹. The overall results suggest that the maceration of waste cork in binary solvents and pure acetone are green alternatives to conventional Soxhlet extraction for the production of polar extracts. Full article

The effect of bad air quality on human health is a well-known risk. Annual health costs have significantly been increased in many countries due to adverse air quality. Therefore, forecasting air quality-measuring parameters in highly impacted areas is essential to enhance the quality of life. Though this forecasting is usual in many countries, Sri Lanka is far behind the state-of-the-art. The country has increasingly reported adverse air quality levels with ongoing industrialization in urban areas. Therefore, this research study, for the first time, mainly focuses on forecasting the PM₁₀ values of the air quality for the two urbanized areas of Sri Lanka, Battaramulla (an urban area in Colombo), and Kandy. Twelve air quality parameters were used with five models, including extreme gradient boosting (XGBoost), CatBoost, light gradient-boosting machine (LightBGM), long short-term memory (LSTM), and gated recurrent unit (GRU) to forecast the PM₁₀ levels. Several performance indices, including the coefficient of determination (R²), root mean squared error (RMSE), mean absolute error (MAE), mean squared error (MSE), mean absolute relative error (MARE), and the Nash–Sutcliffe efficiency (NSE), were used to test the forecasting models. It was identified that the LightBGM algorithm performed better in forecasting PM₁₀ in Kandy (${\mathrm{R}}^2=0.99, \mathrm{MSE} =0.02, \mathrm{MAE}=0.002, \mathrm{RMSE} =0.1225, \mathrm{MARE} =1.0, \mathrm{and} \mathrm{NSE}=0.99)$. In contrast, the LightBGM achieved a higher performance (${\mathrm{R}}^2=0.99, \mathrm{MSE} =0.002, \mathrm{MAE} =0.012 , \mathrm{RMSE} =1.051, \mathrm{MARE} =0.00, \mathrm{and} \mathrm{NSE}=0.99)$ for the forecasting PM₁₀ for the Battaramulla region. As per the results, it can be concluded that there is a necessity to develop forecasting models for different land areas. Moreover, it was concluded that the PM₁₀ in Kandy and Battaramulla increased slightly with existing seasonal changes. Full article

Ammonia-nitrogen (NH₃-N) loss from agriculture decreases crop yield potential and environmental quality. Incorporating animal manures by chisel plowing (CP) can reduce NH₃ loss but may increase crop residue loss compared to lower disturbance incorporation methods and vertical tillage (VT). Few studies have evaluated VT efficacy for incorporating manure and reducing NH₃ concentrations compared to traditional tillage tools, such as CP. Six trials during 2013 to 2016 were conducted to evaluate the impacts of manure incorporation method (CP, VT, or broadcast) and weather conditions at the time of application on NH₃-N concentrations at a dairy research farm in central Wisconsin, USA. Passive samplers measured NH₃-N concentrations at 30-cm above the ground during the first 0 to 24 and 24 to 48 h post-manure application/incorporation. Average NH₃-N concentrations for CP and VT were 44 to 86% of broadcast and similar for most trials, while crop residue coverage for VT was greater than CP (39 and 22% of control plots, respectively). Concentrations of NH₃-N were correlated with the amount of plot area covered by manure for the first (r = 0.56, p < 0.0001) and second measurement periods (r = 0.85, p < 0.0001). Results show that VT had comparable NH₃-N concentration reductions to CP while conserving more crop residue. Full article

The EN 1793-5 and EN 1793-6 standards have been in use for many years as a method for measuring the intrinsic characteristics of noise barriers installed along highways and railways. They require a sound source and a grid of microphones, to be placed near the barrier and in free field conditions, according to predetermined distances. In principle, small errors in positioning the sound source and microphone grid may affect the results obtained. An international round-robin test was carried out in 2012 to evaluate the repeatability and reproducibility of the method, but until now no studies have been carried out to evaluate and compare the repeatability of laboratory versus in-place measurements performed with the same equipment and its variance when an imperfect positioning of sound source and microphones is taken into account. In the present work, multiple series of sound reflection index and sound insulation index measurements performed on noise barriers of the same kind installed in the laboratory or along a highway are presented. The measurements were repeated in different ways: (1) in the laboratory, leaving the source and microphones unmoved to assess the repeatability of the results and of the measurement system under controlled conditions; (2) in the laboratory, repositioning for each measurement the source and microphone grid to assess the robustness of the method under real conditions but in a controlled environment; (3) in situ, along a highway open to traffic, repositioning for each measurement the source and microphone grid to assess the repeatability of the method under real conditions in a critical environment. In both reflection index and sound insulation index measurements, the standard deviation on single-number ratings in all cases examined is well below the value presented in EN 1793-5 and EN 1793-6, which was obtained from statistical analysis of the international round-robin test performed a dozen years ago, suggesting that expert operators with state-of-the art equipment can achieve much better results now. Full article

An increase in population along the Indian River Lagoon has led to eutrophication, a decline in water quality, and overall degradation. The Living Docks program is a citizen–science initiative started at the Florida Institute of Technology for lagoon restoration. Public and private docks are volunteered to become Living Docks, where oyster mats are attached to dock pilings to provide a natural substrate for benthic organism growth. The community development on the oyster mats boosts water filtration to improve overall water quality and combat anthropogenic effects on the lagoon. The purpose of this project was to model benthic settlement and recruitment of prominent organisms on the Living Dock oyster mats at four research sites with specific environmental factors (e.g., temperature, salinity, turbidity, and pH). Beta regression models for recruitment and settlement were created for five of the more dominant organisms observed: oyster, barnacle, sponge, tubeworm, and encrusting bryozoan. The results of the modeling indicated that the settlement was influenced by pH, salinity, dock location, and turbidity, while recruitment was influenced by pH, salinity, dock location, and immersion time. This project provides insight into how lagoon conditions surrounding the Living Docks impact benthic growth and can aid in IRL restoration. Full article