In this study, chrysin as a natural flavonoid was encapsulated in nanoliposomal structures, and the synthesized nanoliposome-loaded chrysin (NLC) was further characterized for its physical properties and cytoprotective effects in mice that received cadmium-containing water. The results showed that the synthesized NLC is possessed spherical structure with the size of 185.1 nm and negative surface charge of − 26 mV with a poly dispersity index of 0.26. The mice received cadmium (2 mg/kg body weight/day) through drinking water showed weight loss and decease in the feed intake significantly (p ≤ 0.05). The cadmium notably (p ≤ 0.05) increased the liver enzymes including aspartate aminotransferase, alanine transaminase, and alkaline phosphatase; altered the liver metal deposition (cadmium, copper, manganese, selenium, and zinc); and induced hepatic oxidative stress (inducible nitric oxide synthase, catalase, superoxide dismutase, and glutathione peroxidase genes) with no remarkable histopathological changes. Furthermore, the cadmium impaired the morphology of jejunum through reducing villus height and villus width and increasing the crypt depth. Providing NLC as a dietary supplement at the concentrations of 2.5 and 5 mg/kg mice body weight significantly (p ≤ 0.05) improved the feed intake and body weight gain, modulated the liver enzymes, and alleviated the hepatic oxidative stress. The NLC also improved the antioxidant mineral deposition in the liver and morphohistological structure of jejunum. Consequently, the NLC is suggested as a potential dietary supplement to alleviate the symptoms of cadmium-induced toxicity in mice.

In this work, the synthesized slow pyrolysis biomass pine cone (Pinus radiata)–based biochar was acid activated, characterized, and tested for its effectiveness in the adsorptive removal of aqueous-phase Pb²⁺ metal ions. The adsorbent surface modification was conducted by treatment with H₂SO₄ and H₃PO₄ and was characterized by BET surface area, pore volume, pore size, C-H-N-S analysis, the presence of various functional groups through FT-IR (Fourier Transform- Infrared), the crystallinity of the material and presence of minerals by XRD (X-ray diffraction spectrum), and surface morphology by FESEM. The specific surface area after acid modification has been increased from 145 to 472 m²/g. Also, acid treatment causes an increase of the COO⁻ functional group on the adsorbent surface which are responsible for adsorption. All three types of biochar, namely BC (raw biochar without modification), AC1 (modified by H₃PO₄), and AC2 (modified with H₂SO₄) were used for the removal of aqueous-phase Pb²⁺ by batch adsorption and compared. Various physicochemical process parameters such as initial solution pH, initial metal ion dose or adsorbate concentration, adsorbent dose, and system temperature and their effect on metal ion adsorption mechanism have been identified and optimized here. Maximum Pb ²⁺ adsorption capacities were obtained as 251, 283 mg/g and 321 mg/g for BC, AC1, and AC2 respectively which are very much comparative with other reported adsorbents including commercial activated carbon under similar experimental conditions. This study indicated that pine cone biochar was an environment-friendly and cost-effective adsorbent in sustainable solution for water and wastewater treatment.

The Kaban Lakes Integrated Assessment Model (KLIAM) was enhanced in order to assess the possible content of antibiotics in the Kaban lakes, located within the city borders of Kazan City, Tatarstan Republic in the Russian Federation, and potential for adverse environmental effects. The Kaban Lakes Integrated Assessment Model simulations suggest that the concentrations in the Nizhniy Kaban lake and Sredniy Kaban lake may exceed the predicted no effect concentration (PNEC) and low-risk limits set by EU and the WHO. Many missing data could be assumed or approximated, and simulation runs were conducted. The results are consistent with other global studies in terms of average concentrations observed elsewhere in rivers and lakes. The results suggest that the study should be followed up with lake water analysis and an assessment of antibiotic loads to the Kaban lakes. It is concluded that the results are too uncertain to initiate any policy action at the present moment and that an assessment supported by measurements would be warranted.

Environment-economic growth nexus is one of the main concerns of the researchers in the modern era. Although there are several studies in this field, discussions are far from being reached a consensus. The main purpose of this study is to investigate the role of economic growth, renewable and non-renewable energy consumption, oil prices, and trade openness on CO2 emissions in 25 Organization for Economic Co-operation and Development (OECD) countries over the period 1990–2014. We provide a comparative panel data evidence using both the first- and second-generation estimation methods. The Fully Modified Ordinary Least Squares (FMOLS) and Dynamic Ordinary Least Squares (DOLS) estimations indicate that the Environmental Kuznets Curve (EKC) hypothesis is valid in OECD countries. However, the Augmented Mean Group (AMG) estimator revealed that the EKC hypothesis is invalid. The AMG estimator is a second-generation estimator and provides robust results under cross-sectional dependence compared to the first-generation methods; therefore, the EKC hypothesis is invalid. Our additional findings show that rising renewable energy consumption and oil prices mitigate CO2 emissions while non-renewable energy consumption increases it according to all estimators. No significant relationship is found between trade openness and CO2 emissions.

In the last few years, neurodegenerative diseases like Alzheimer’s disease (AD) and Parkinson’s disease (PD) have attracted attention due to their high prevalence worldwide. Environmental factors may be one of the biggest reasons for these diseases related to neuronal dysfunctions. Most of neuronal disorders are strongly associated with pre- and postnatal exposure to environmental toxins released from industries. Some of the neurotoxic metals such as lead, aluminum, mercury, manganese, cadmium, and arsenic as well as some pesticides and metal-based nanoparticles have been involved in AD and PD due to their ability to produce senile/amyloid plaques and NFTs which are the main feature of these neuronal dysfunctions. Exposure to solvents is also majorly responsible for neurodegenerative disorders. The present review highlights the impact of omnipresent heavy metals with some other neurotoxins on human health and how they give rise to neuronal dysfunctions which in turn causes socio-economic consequences due to increasing pollution worldwide. Graphical abstract

Well-defined targets for nitrogen (N) release into the local environment are essential for water management in creeks, but difficulties often arise from working with data that are too sparse to achieve reliable evaluations. Here, a simulation–optimization approach based on the QUAL2K model was developed to put forward strategies for nitrogen pollution control in a creek with sparse data in Shixi Creek, southeast China. The model showed good agreement with field observations from 22 sampling sites sampled over the period from March 2017 to February 2019, with normalized objective function (NOF) less than 0.360. Based on this model, the water pollutant sources in the creek were distinguished and analyzed. Rural sewage discharge in Shixi Creek was the major factor threatening water quality in the stream. Seasonal variations may influence the transformation of riverine N. To make more than 80% of the area in Shixi Creek meet the water quality standard of grade III, an optimized approach is to reduce more than 55% of the N pollution from point source pollution and 10% from nonpoint source pollution. This study proposed an approach that can effectively evaluate strategies for water management in a creek watershed with sparse data.

Antibiotics are among the most extensively used pharmaceuticals worldwide. They are natural or synthetic drugs with the capacity to kill or inhibit the growth of microorganisms. Several antibiotics have been detected in aquatic environments, but little is known about their effects on non-target organisms, especially fish. The aim of this study was to evaluate the effects of the antibiotic nitrofurantoin (NTF) using zebrafish embryos as model organisms. To assess mortality and development effects, the embryos were exposed to 0, 4, 9, 44, 100, 223 and 500 mg/L of NTF. A sub-lethal range of concentrations (0, 0.001, 0.02, 0.32, 5.62 and 100 mg/L) was used for biomarker analyses, namely cholinesterase, lactate dehydrogenase, glutathione S-transferase and catalase. The results indicated low toxicity of NTF to zebrafish, with a 168 h-LC₅₀ value of 129.2 mg/L. The main effect on development was the loss of equilibrium related to the uninflated swim bladder (168 h-EC₅₀ = 96.72 mg/L). Biomarker activity was induced in concentrations as low as 0.02 mg/L (cholinesterase, lactate dehydrogenase, glutathione S-transferase). Exposure to NTF induced no significant effects on zebrafish larvae behaviour. In summary, short-term exposure of zebrafish embryos to NTF induced developmental alterations only at high concentrations. However, biochemical changes occurred at lower levels of exposure, suggesting long-term effects on fish populations. Graphical Abstract

The adsorption potential of layered double hydroxides (LDH) of nickle–zinc–iron (NiZnFe) and its composites with single-wall carbon nanotubes (CNTs) and banana biochar (Bb) was investigated for divalent copper (Cu²⁺) removal in a batch system. Field emission scanning electron microscopy and FT-IR spectra confirmed the adsorption of Cu²⁺ onto LDH (NiZnFe) and its composites with Bb (LDH/Bb) and CNTs (LDH/cnt). The optimum equilibrium contact time was determined to be ~ 30 min, with LDH/Bb displaying the maximum uptake and removal efficiency (95%) for an initial Cu²⁺ concentration of 20 mg L⁻¹. Pseudo-second-order kinetic models presented high R² values (1.0) for all adsorbents, indicating good agreement between the theoretical adsorption capacities with experimental values. Multistep adsorption with both the surface and pore diffusion mechanism was suggested as well based on the intraparticle diffusion kinetic model. An optimum pH of 5.0 was considered with an increase in the uptake of Cu²⁺ and its removal efficiency, wherein LDH/Bb presented a greater removal efficiency and higher Cu²⁺ uptake compared with that of LDH (NiZnFe) and LDH/cnt. A gradual increase in Cu²⁺ uptake was observed in association with an increase in adsorbent dose from 0.2 to 0.5 g, with insignificant changes upon further increasing the dose of the adsorbent from 0.5 to 0.9 g. An increase in the initial Cu²⁺ concentrations from 10 to 100 mg L⁻¹ resulted in a decrease in the removal efficiency, whereas Cu²⁺ uptake increased almost linearly in the Cu²⁺ concentration range of 10–60 mg L⁻¹. Results of experimental data fitting using the Langmuir and Freundlich isotherm models suggest a dominance of monolayer adsorption, although multilayer adsorption appears to occur onto adsorbents with heterogeneous surfaces. Notably, chemisorption was also proposed to occur owing to the values of mean free energy of adsorption falling in the 8–16-kJ mol⁻¹ range, as calculated using the Dubinin–Radushkevich isotherm model. Importantly, the use of the SIP isotherm model indicated LDH/Bb to exhibit higher energy of adsorption and degree of heterogeneity than other two adsorbents. Thus, biochar or CNTs composited NiZnFe-LDH could serve as efficient adsorbents for Cu²⁺ removal from wastewater streams.

In the process of identifying groundwater pollution sources, in order to solve the problem that the monitoring data of monitoring wells was insufficient or the correlation between monitoring data and model parameters was weak, a monitoring well optimization method based on Bayesian formula and information entropy was proposed. Two-dimensional phreatic groundwater solute transport model was built and solved by using GMS software. To reduce the computational load of calling the numerical model repeatedly in the optimization design of the monitoring schemes and the identification process of the pollution sources, the Kriging method was used to establish the surrogate model of the numerical model. Under the condition of single well monitoring and determined monitoring frequency, with the target of optimization of monitoring position number D and monitoring time interval ∆t, both the single-objective monitoring scheme with the minimum information entropy of the model parameter posterior distribution and the multi-objective monitoring scheme with the minimum information entropy and the shortest monitoring time were optimized respectively. According to the above-optimized monitoring schemes, the delayed rejection adaptive Metropolis algorithm was used to identify the pollution source parameters. The case study results showed that under the condition of pre-set single well monitoring with monitoring frequency of 10 times, the single-objective optimized monitoring scheme was D = 37 and Δt = 20 days. Under this monitoring scheme, the mean errors of inversion pollution source parameters α = (XS, YS, T₁, T₂, QS) were 0.09%, 0.4%, 4.72%, 2.43%, and 9.29%, respectively. The multi-objective optimized monitoring scheme was D = 37 and Δt = 2 days. Under this monitoring scheme, the mean errors of the inversion parameters α = (XS, YS, T₁, T₂, QS) were 12.76%, 3.77%, 5.13%, 1.36%, and 7.68%, respectively. Compared with the monitoring scheme based on the single-objective optimization, although the inversion mean error of the five parameters based on the multi-objective optimized monitoring scheme increased by 2.75%, the monitoring time significantly reduced from 180 to 18 days.

This paper shows the possibility of using steam pretreatment to improve the efficiency of membrane recovery chemical cleaning. Before applying chemicals to clean a fouled membrane, steam pretreatment was employed to loosen the structure of the foulant layer and weaken the attachment of those foulants on the membrane. Although longer steam contact times would lead to even better cleaning efficiency, the steam pretreatment duration was limited to less than 2 min to maintain membrane integrity. When cleaning fouled membranes with 1 mol/L HCl, the cleaning efficiency without steam pretreatment went from 83.3 to 90.2% as cleaning time increased from 30 to 180 min. As for 90-s steam pretreatment, the cleaning efficiency showed high values of more than 93% regardless of cleaning time. When the concentration of HCl was decreased to 0.2 mol/L, the cleaning efficiencies with a 90-s steam pretreatment was 78.6% and 92.6% for relatively short cleaning times of 30 and 60 min, respectively; this is much higher than the 62.2% and 76.7% achieved when cleaning without steam pretreatment. In addition, when using alkaline solution as the cleaning chemical, similar results were obtained. This implies that the application of steam before chemical cleaning is effective in improving cleaning efficiency, and so, this technique has the potential to reduce the amount of cleaning chemical required for membrane recovery cleaning.