The interfacial activity of dispersants can be enhanced by combining two or more surfactants to formulate the dispersant. This paper examines the effects of Bio-Saponin (BS), a phytogenic surfactant on the interfacial activity of synthetic dioctyl sulfosuccinate sodium salt (DOSS) usually adopted as a suitable surface-active agent in dispersants used in dealing with large-scale oil spills. The o/w emulsion created with the binary DOSS-BS was very stable and recorded the least average droplet size compared with that of DOSS only and BS only. Lower surface and interfacial tension values were also obtained from the DOSS-BS binary formulation. The dispersion effectiveness was also higher compared with that of DOSS and BS. However, they were dependent on the salinity and type of crude oil. These observations were attributed to the moderation of the interaction between the anionic head group of DOSS by the polysaccharide hydrophilic group of BS. The results revealed the potential application of DOSS-BS binary dispersant in oil spill remediation and in other processes that would require an effective emulsifier.

The efficiency of two common Mediterranean agroforestry systems, a potato-poplar and a maize-poplar, was assessed with respect to the uptake of nutrients and pesticides in an experimental plot located in Attica, Greece, during the cultivating period of 2016. Soil samples were collected on a monthly basis at different soil horizons and varying distance from the tree row. The monitored substances included all nitrogen ions (NO₃⁻-N, NO₂⁻-N, NH₄⁺-N), phosphates (PO₄³⁻-P), potassium (K⁺), the insecticide chlorpyrifos, as well as the herbicides s-metolachlor, pendimethalin, and its metabolite M455H001. Experiments for the potato-poplar system exhibited reductions of more than 86% for K⁺, 90% for NO₃⁻-N, 92% for NH₄⁺-N, 85% for NO₂⁻-N, and up to 100% for PO₄³⁻-P. Accordingly, for the maize-poplar system, reductions were more than 73% for K⁺, at least 77% for NO₃⁻-N, approximately 77% for NO₂⁻-N, 97% for NH₄⁺-N, and up to 100% for PO₄³⁻-P. Regarding the examined pesticides, all substances reached more than 61.5% and up to 100% disappearance in the closest to the tree row points compared to the control points, thus also exhibiting the potential for tree uptake of the excess pesticides. As such, it was demonstrated that agroforestry alley cropping systems may act as a technique for pollution abatement, since tree roots that extend below the crops can uptake the excess of agrochemicals that would otherwise enter groundwater via leaching or surface water via runoff.

Activated carbon adsorption has been considered the most efficient technology toward VOC removal. The waste biomass as alternates solved the problems of high price and nonrenewable of traditional raw materials. The waste Zanthoxylum bungeanum branches were firstly selected as raw materials to prepare activated carbons. Interestingly, the pore structure and surface chemistry can be successfully controlled by adjusting the heating rate. The hierarchical porous carbons exhibited great potential for toluene adsorption. The micro-mesopore structure possessed unique spatial effect; micropores played a dominant role in adsorption process, especially narrow micropores (pore size ≤ 1.0 nm) emerged stronger adsorptive force toward toluene molecules due to overlapping attractive forces from neighboring pore walls. And mesopores not only displayed excellent transport diffusion but also provided adsorption sites. Additionally, the high graphitization degree enhanced the interaction between graphene layer equipped electron-rich regions and π-electrons on the aromatic ring by the π-π conjugated effect. The hydroxyl and carbonyl functional groups served as chemisorption sites and led to higher adsorption amounts. Fortunately, the regeneration can be achieved by thermal treatment at the low temperature (≤ 150 °C) or even gas purging at room temperature (20 °C), which avoided an explosion accident in the process of high-temperature regeneration.

The objective of this study was to demonstrate biochar’s effectiveness on Ni(II) removal from aqueous solutions by adsorption on three different biochars. Three different waste feedstocks, namely sewage sludge, exhausted olive pomace and the organic fraction of municipal solid waste, were used to produce biochar through pyrolysis at 300 °C, under inert conditions. The obtained biochars were characterized regarding their main properties and then evaluated as potential Ni(II) adsorbents. All investigated materials showed high adsorption efficiency in the range of 78–97%, with the biochar derived from SS exhibiting the best results, possibly because of its higher cation exchange capacity. Ni(II) removal rates were higher when the adsorption experiments were conducted at natural pH, while the removal efficiency under adjusted pH (acidic or alkaline) was slightly lower. The pseudo-second-order kinetic model adequately described the adsorption kinetics depicting high correlation coefficients, while the Freundlich adsorption isotherm model was successful in simulating equilibrium of adsorption.

The critical role of electricity consumption in influencing and reshaping the economic and environmental landscape of the global economy cannot be underestimated. Electricity is the most beneficial and commonly transformed energy source; however, the strength, weakness, opportunities and threat of its consumption require scientific scrutiny. This study investigates electricity-led growth hypothesis vis-à-vis its impact on economic growth and environmental quality of Turkey. The annual time series data set from 1970 to 2014 were employed in the analysis with a battery of unit root and stationary tests. The equilibrium relationship in the study is explored using Maki and Bayer-Hanck combined cointegration tests under multiple structural breaks along with the Pesaran’s ARDL bounds test procedure for robust check. The study confirms the existence of cointegration relationship between electricity consumption, economic growth, capital, labour and ecological footprint. To detect the direction of causal relations, the VECM Granger causality test is employed. The causality analysis provides empirical evidence that supports the electricity-induced growth hypothesis in Turkey. This implies that embarking on conservative energy-efficient policies will slow down Turkey’s economic growth. Thus, precautionary measures that ensure adequate policy on energy mix to guarantee availability and accessibility to modern electricity will sustain economic growth and improve environmental sustainability.

The essential oil (EO) of Thymus serpyllum and thymol were evaluated for their insecticidal activity against the housefly (Musca domestica) larvae and pupae. Contact toxicity and fumigation bioassays were used. Chemical composition analysis of T. serpyllum EO by gas chromatographic mass spectrometry (GC-MS) revealed that thymol (41.6%), p-cymene (21.9%), and γ-terpinene (19.2%) were the major components. For larval assays, the LC₅₀ value of T. serpyllum EO was 0.4 μl/cm² for contact toxicity and 20.9 μl/l for fumigation toxicity. For thymol, the contact toxicity LC₅₀ value was 0.035 μl/cm² and the fumigation LC₅₀ value was 2.0 μl/l. For the pupal assay, T. serpyllum EO had a percentage inhibition rate (PIR) value of 100% for both contact toxicity (1.0 μl/cm²) and fumigation toxicity assay (25 μl/l), whereas thymol had a PIR of 100% for contact toxicity (0.1 μl/cm²) and fumigation assay (5 μl/l). This study shows that T. serpyllum EO and thymol are toxic to housefly larvae and pupae and have the potential for use in the population control of this species.

Coal gangue hills are prone to spontaneous combustion, thereby polluting the environment of mining areas such as the soil, groundwater, and atmosphere, and the frequent occurrence of gangue hill collapses, landslides, explosions, and other accidents can even endanger the lives and property of residents. To realize the safety management of coal gangue spontaneous combustion and evaluate its present risks, this paper selects the Dongzhou Kiln gangue hill in Zuoyun County, Datong City, China, as the research object to conduct a risk assessment study. The Dongzhou gangue hill fire area is relatively large, with a total area of 183,039 m². Smoke emission commonly occurs at the site, and the surface temperature reaches 50 °C, while the CO concentration exceeds 10⁻³. A radon detection scheme for concealed fire zones verified with borehole temperature measurements is applied. The high-temperature area is delineated with relevant data obtained by infrared thermal imaging, radon concentration, and borehole temperature detection technologies, and a coal gangue spontaneous combustion risk assessment method is established, while the gas toxicity and explosion risks of the construction area and fire trends are analyzed. The research results indicate that there are 6 likely high-temperature regions in the test area, 4 high-toxicity areas in the drilling construction area, 1 area with a high explosion risk, and 3 areas with a high risk of spontaneous combustion. Among these areas, platform 2 is a high-risk area and needs to be carefully considered. The construction of the entire area is at high risk, including toxicity, gas explosion, and spontaneous combustion risks, and measures must be implemented to reduce the overall risk.

The application of hydrogen peroxide (H₂O₂) as a management tool to control Microcystis blooms has become increasingly popular due to its short lifetime and targeted action. H₂O₂ increases intracellular reactive oxygen species resulting in oxidative stress and subsequently cell death. H₂O₂ is naturally produced in freshwater bodies as a result of photocatalytic reactions between dissolved organic carbon and sunlight. Previously, some studies have suggested that this environmental source of H₂O₂ selectively targets for toxigenic cyanobacteria strains in the genus Microcystis. Also, past studies only focused on the morphological and biochemical changes of H₂O₂-induced cell death in Microcystis with little information available on the effects of different H₂O₂ concentrations on growth, esterase activity and membrane integrity. Therefore, this study investigated the effects of non-lethal (40–4000 nM) concentrations on percentage cell death; with a focus on sub-lethal (50 μM) and lethal (275 μM; 500 μM) doses of H₂O₂ on growth, cells showing esterase activity and membrane integrity. The non-lethal dose experiment was part of a preliminary study. Results showed a dose- and time-dependent relationship in all three Microcystis strains post H₂O₂ treatment. H₂O₂ resulted in a significant increase in intracellular reactive oxygen species, decreased chlorophyll a content, decreased growth rate and esterase activity. Interestingly, at sub-lethal (50 μM H₂O₂ treatment), percentage of dead cells in microcystin-producing strains was significantly higher (p < 0.05) than that in non-microcystin-producing strains at 72 h. These findings further cement our understanding of the influence of H₂O₂ on different strains of Microcystis and its impact on membrane integrity and metabolic physiology: important to future toxic bloom control programmes.

The Upper Silesian basin belongs to the largest industrial pollution sources in Europe and the city of Ostrava ranks among the worst-polluted urban areas in the European Union. To assess temporal and spatial trends in atmospheric pollution, we determined concentrations of S, Pb, Cu, Zn, As, Cd, Sb, and Al in snow in downtown Ostrava and at the Lysa Hora Mt. (LH), situated 33 km southeast. Snowpack surfaces were sampled in February 2011/2012, 2018, and 2019. At LH, we collected snow samples at four elevations (700, 900, 1100, and 1300 m) in order to quantify mountain slope gradients in the pollution that, in turn, might reflect vertical stratification of air masses in a region frequently affected by temperature inversions. ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb isotope ratios and back trajectories of air masses were used for pollution source apportionment. In year 1, there were clear-cut upslope decreases in concentrations of soluble pollutants. By year 3, the concentrations of soluble pollutants at LH decreased by 90% and the concentration gradients ceased to exist. Because annual precipitation totals at LH increase upslope by 75%, rates of deposition of soluble pollutants are now higher at the summit than those at the foot of the mountain. Hydrological control of deposition rates of soluble pollutants thus plays a more important role under lower pollution levels. Concentrations of soluble pollutants in Ostrava were up to 36 times higher compared with those at LH and also decreased by 90%. Lead isotopes indicated the continuing presence of gasoline Pb in the atmosphere, despite its ban in 2000.

Water supply networks are critical infrastructures essentials to health, safety, economic and social well-being which have to be maintained and preserved to ensure their proper functioning. Considering the importance of these critical infrastructures, the risks to which they are exposed and the consequences of such risks must be analysed. Thus, it is important that companies responsible for the management of these assets incorporate risk management in their activities. In the scope of risk management, this paper intends to identify the vulnerabilities of water supply infrastructures, by analysing the risks they are exposed and identifying the measures that need to be implemented or reinforced. Risk assessment methodologies were analysed to identify the advantages and disadvantages of each one. As a case study, the water supply network of the Aveiro municipality in mainland Portugal was used. This network was analysed resourcing ArcMap, ArcGIS desktop software, which allows a better understanding of the water supply network. Risk management was applied and the probability and possible consequences of six distinct categories of threats were determined in eight scenarios, allowing the development of risk maps concluding that all these scenarios are in a low or medium level of risk. To decrease the vulnerability of the water network, a set of plans and specific measures have to be developed.