Regulatory assessment of the effects of chemicals requires the availability of validated tests representing different environments and organisms. In this context, developing new tests is particularly needed for marine species from temperate environments. It is also important to evaluate effects that are generally poorly characterized and seldom included in regulatory tests. In this study, we designed an exposure protocol using European sea bass (Dicentrarchus labrax) larvae. We examined classical toxicological values (LCx) as well as behavioral responses. By comparing different hatching and breeding strategies, we defined the optimal conditions of exposure as non-agitated conditions in 24- or 48-well microplates. Our exposure protocol was then tested with 3,4-dichloroaniline (3,4-DCA), a recommended reference molecule. Based on our results, the 96 h LC50 for 3,4-DCA corresponded to 2.04 mg/L while the 168 h LC50 to 0.79 mg/L. Behavioral analyses showed no effect of 3,4-DCA at low concentration (0.25 mg/L). In conclusion, the present work established the basis for a new test which includes behavioral analysis and shows that the use of sea bass is suitable to early-life stage toxicity tests.

A novel method for inactivation and removal of orthophosphate (SRP) from eutrophic waters was proposed, based on application of laminates containing calcite mineral (Cc), which serves as a SRP binding agent. Laminates are placed in the water column to allow for SRP sorption onto Cc and then extracted, to remove Cc together with sorbed SRP from the ecosystem. Two Cc materials obtained by planetary ball milling of a ground limestone were used. We investigated (1) physical properties of laminates, (2) their SRP binding efficiency and (3) impact on water chemistry, under variable in-lake situations, simulating turnover, epilimnetic and hypolimnetic conditions, which correspond to equilibrium, oversaturation and undersaturation with respect to Cc, respectively. Laminates coated with Cc removed 9–33% less SRP as compared to loose Cc materials due to deactivation of Cc surface in the laminates. SRP binding by laminates was highly variable (removal of 14–67%) and dependent upon physical and sorption properties of Cc material used as well as environmental conditions, with the highest efficiency in the epilimnetic variant. Under hypolimnetic and turnover conditions, laminates typically slightly, but significantly, enhanced pH, alkalinity, Ca²⁺ concentration and saturation with respect to Cc, whereas in epilimnetic conditions an opposite effect was seen. Although field validations are needed, we propose laminates as a non-invasive, complementary method to traditional chemical SRP inactivation in lakes, to avoid accumulation of SRP binding agents in the environment and secure sustain SRP elimination from the water bodies.

An inflow of foreign capital into the host country would raise her aggregate capital stock, gross savings and investment, economic growth, and environmental quality. This study scrutinizes the asymmetric impact of FDI and remittances to CO2 emissions in China using annual data from 1981 to 2019, via an asymmetric ARDL approach. The findings show that a positive and negative shock in FDI causes a decrease in CO2 emissions in long run. The findings inferred that a negative shock of remittances has a negative impact on the environment by reducing CO2 emissions in long run. While the impact of a negative shock of remittance is more than the impact of a negative shock of FDI on CO2 emissions in long run in China. Thus, government that policymakers should consider foreign capital as a policy instrument especially designing strategies and policies related to environmental sustainability in China.

The following work provides a perspective on the potential application of solar heterogeneous photocatalysis, which is a nonselective advanced oxidation process considered as a sustainable technology, to assist in arsenic removal from water, which is a global threat to human health. Heterogeneous photocatalysis can oxidize trivalent arsenic to pentavalent arsenic, decreasing its toxicity and easing its removal with other technologies, such as chemical precipitation and adsorption. Several lab-scale arsenic photocatalytic oxidation and diverse solar heterogeneous photocatalytic operations carried out in different reactor designs are analyzed. It was found out that this technology has not been translated to operational pilot plant scale prototypes. General research on reactors is scarce, comprising a small percentage of the photocatalysis related scientific literature. It was possible to elucidate some operational parameters that a reactor must comply to operate efficiently. Reports on small-scale application shed light that in areas where other water purification technologies are economically and/or technically not suitable, and the solar energy is available, shed light on the fact that solar heterogeneous photocatalysis is highly promissory within a water purification process for removal of arsenic from water.

While there are enormous studies on climate change in stable countries, climate policy perspectives from conflict-prone regions including Somalia are limited. It is noteworthy that environmental degradation is an alarming issue that fuels the vulnerability of Somalia to climate change. To this end, this study investigates the asymmetric impact of energy and economic growth on environmental degradation in Somalia—by employing nonlinear autoregressive distributed lag model (NARDL) and causal techniques from 1985 to 2017. We find asymmetric long-term cointegration among the variables, whereas energy consumption and economic growth asymmetrically affect environmental degradation. Besides, the causal inferences reveal unidirectional causality from environmental pollution to positive change in energy consumption. Additionally, a bidirectional causality is observed between population growth and negative change in economic growth. A unidirectional causality is confirmed: from positive shock in economic growth to population growth—from a negative change in economic growth to negative shock in energy consumption—from positive change in economic growth to positive shock in energy consumption—and from a negative change in energy consumption to population growth. This calls for the implementation of clean energy investment and modern environmental strategies including good farming methods and improved grazing land policies. The adoption of these policies will improve both environmental quality and sustained economic development.

Solar energy-driven evaporation-based freshwater production is one of the sustainable ways to purify contaminated/salty water. Recent advances in solar absorbers’ assemblies, design modifications, and integrations with heating sources improved the rate of freshwater productivity. However, the type of feed water affects the evaporation rate in a solar desalination system (SDS). Many studies used tap water with added contaminants to test the performance of a SDS and studied the water quality improvement. As a typical result, pH, total dissolved solids (TDS), and electrical conductivity (µS/cm) are reduced after solar evaporation. The performance of SDSs for real wastewaters are also important to understand, e.g., the reduction of high organic pollutants after solar evaporation. In this aspect, the main objective of the present work is to review solar distillation of real wastewaters and seawater by using SDSs. Further, the mechanism of a solar distiller with heat transfer principles, parameters affecting evaporation process, real wastewaters and seawaters purified in a solar distillation system, improvement of various parameters before and after solar evaporation, pathways of handling wastewaters, challenges, and future perspectives are discussed. Conclusively, SDSs are found to remove pollutants effectively after solar evaporation. The evaporation rate is relatively slower due to high concentration of pollutants that reduce vapor pressure. The COD removal of various real wastewaters, including sludge, kitchen, textile, palm oil, petroleum, water plant, and municipal wastewaters, was 98.13%, 97.85%, 96.84%, 96.71%, 87.99%, 86.99%, and 85.67%, respectively. The reduction rate of salt concentration in real seawater after evaporation in the solar distiller was 99.99%.

The aim of study is to estimate the role of energy financing for energy retrofit in COVID-19, with the intervening role of green bond financing. For this, Kalman technique is applied to infer the empirical findings. It is found that energy financing is significantly dependent on green bonds, and green bonds have a significant role in energy retrofit in E-7 economies specifically. It is further found that E-7 economies gained significant rise in energy efficiency financing green bonds financing, that has supportively extended energy retrofit - before and during COVID-19 crises. It is further found significant that the E-7 nations have to put alot of money into hydro and nuclear energy for energy retrofit, with low carbon emissions. In the light of COVID-19 crises, this study offers policy recommendations for effective energy management. However, such policy recommendations are expected to finely serve the financial intermediaries and national governments of E-7 economies to better optimize energy financing through green bond financing. The novelty of the study exists in topical framework and research directions, talking about the way forwards for energy efficiency financing - which is one of the latest issue of the recent times. Hence, this research provides some empirical verifications about energy financing in COVID-19 crises for energy retrofit, and shares some suggestions for stakeholders.

This systematic review aims to identify the sources of exposure to polychlorinated biphenyls (PCBs), portioning, and human health risk assessment in Iran. The literature was searched in the international databases of Web of Science, PubMed, Scopus, Google Scholar, and the national databases of SID and MagIran up to November 14, 2020. Among all 153 articles, 21 eligible papers were identified. Among them, only one article was related to drinking water, the rest was related to food and soil, and no article was found on ambient air. The corrected portion of each exposure source was determined to be 90% for food, 9% for water, and 1% for air. The total hazard quotient (HQ) was determined to be within an unsafe range, and the total excess lifetime cancer risk (ELCR) was determined to be at a high risk of oral carcinogenesis. It is suggested that a comprehensive study be conducted in a specific period for all sources of exposure in all counties of Iran. Moreover, it is recommended that the policymakers set national standards for this pollutant in near future in some sources of exposure (e.g., drinking water) which have no standards in Iran.

Sunlight active blue emissive zirconium, nitrogen, and sulfur co-doped carbon dots (Zr-N-S-CDs) have been synthesized by microwave-induced pyrolysis for achieving efficient photocatalytic degradation of pollutant malachite green dye (MG) in water. Surface morphology studies using high-resolution transmission electron microscopy confirmed the formation of spherical-shaped CDs with an absorbance peak at 350 nm and emission peak at 437 nm in UV–vis and fluorescence spectroscopy, respectively. Surface functional groups, elemental composition, and metal/non-metal co-doping were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. To understand the photocatalytic performance of Zr-N-S-CDs, various parameters, such as the source of energy, concentration of dye, catalyst dosage, and change in pH, were investigated. MG dye (20 ppm) at a pH 7 with 0.5 mg/mL of Zr-N-S-CDs could be photodegraded efficiently in 90 min under sunlight (99%) compared to dark and artificial light conditions. Moreover, real-time analysis of degradation rate could be conveniently calculated by integrating the colorimetric responses of MG dye with RGB values obtained by the “Color Picker” app of a smartphone. The degradation rate obtained using a smartphone (97.89%) was found to be in agreement with the UV–vis spectroscopy (99%), thus, providing a new, handy, and instrument-free route for speedy and quantitative estimation of the degradation of hazardous MG dye by Zr-N-S-CDs.

In this study, the alginate/hydroxyapatite/graphene oxide (AHGO) nanocomposite hydrogel beads (nhb) were designed, synthesized by an ionotropic gelation technique, and studied as an efficient, environment-friendly adsorbent for cationic dyes. The adsorptive capacities of AHGO nanocomposite toward methylene blue (MB) as a model dye solution were investigated through batch adsorption experiments in which the effects of initial dye concentration, adsorbent dosage, pH, temperature, ionic strength, and contact time on MB removal efficiency were examined. To explore the adsorption mechanisms, adsorption kinetics, isotherm analyses, XRD, FTIR, SEM–EDS, and point of zero charge (pHPZC) were performed. The results showed that AHGO-nhb had a maximum adsorption capacity of 311.81 mg/g for MB. This suggests that AHGO could be a good adsorbent for getting dyes out of water. Adsorption kinetics measurements proved to be closely correlated with both first and pseudo-second order (PSO) kinetics at the start, with the PSO taking control after 75 min, whereas the Sips model best described the MB adsorption isotherm process on AHGO. Based on the thermodynamic values ΔG°, ΔS°, and ΔH°, the process was spontaneous and exothermic in nature for cationic dyes. The mechanism underlying MB removal by AHGO is primarily a surface phenomenon involving electrostatic interaction, n-π interaction, and π-π interaction without intercalation. The process was shown to be a sequence of film diffusion followed by intra-particle diffusion, as demonstrated by the Weber-Moris and Boyed models. The adsorbent still maintains its adsorption ability for up to five cycles and could be a good alternative for treating wastewater.