In the current study, the toxicity bioassay of three pollutants abamectin (ABM), thiamethoxam (TMX), and acrylamide (ACR) against land snails Theba pisana was measured. Also, the ecotoxicological effects of dietary exposure to sublethal concentration (1/20 LC₅₀) of these pollutants for 2-week exposure and 1-week recovery on some physiological endpoints evaluated as feeding activity, growth response, and carbonic anhydrase activity as a marker in charge of shell formation and seromucoid level as a marker in charge of mucus synthesis of the snails were studied. The results exhibited that the 48-h LC₅₀ values were 0.91, 313.8, and 45.7 μg/g dry food for ABM, TMX, and ACR, respectively. The sublethal concentrations of these pollutants in the diet after 2-week exposure were found to reduce the food consumption and inhibit growth rate of the snails. Also, the data illustrated that carbonic anhydrase activity was significantly decreased. On the other hand, there was a significant increase in the seromucoid level as a marker responsible for mucus synthesis in ABM- and TMX-exposed snails, while ACR showed significantly decreased level when compared to control. After 1-week recovery, the tested endpoints of treated snails were slightly repaired but still less than that of the untreated animals. The overall outcome of this investigation suggests the utility of this animal as a good bioindicator organism for ABM, TMX, and ACR exposure in pollution monitoring studies.

Silver nanoparticles (AgNPs) were prepared by reacting Kyllinga brevifolia extract (KBE) with AgNO₃ aqueous solution at room temperature (22 ± 3 °C). The phytochemical constituents in KBE responsible for the reduction process were identified as carbohydrate, protein, and plant sterols (stigmasterol and campesterol). KBE was also found to function as a capping agent for stabilization of AgNPs. The AgNPs were stable at room temperature and had a quasi-spherical shape with an average particle size 22.3 nm. The use of KBE offers not only eco-friendly and non-pathogenic path for AgNPs formation, it also induced rapid formation of the AgNPs. Methylene blue (MB) removal was then done on the AgNPs in the presence of either KBE or NaBH₄. Ninety-three percent removal of MB was achieved with a rate of reaction 0.2663 min⁻¹ in the solution with KBE+AgNPs (pH 2). However, in NaBH₄+AgNPs system, 100% MB removal was achieved at pH 8–10. The reaction rate was 2.5715 min⁻¹ indicating a fast removal rate of MB dye. The process of reduction occurs via electron relay effect whereas in KBE+AgNPs system, sedimentation occurred along with the reduction process. Nevertheless, the use of KBE+AgNPs system is preferred as the reducing agent is more benign to the environment.

The goals of this paper are to examine whether the environmental Kuznets curve (EKC) holds and to investigate whether renewable energy consumption can decrease CO₂ emissions in the USA using monthly data spanning the period 2000:M01–2018:M07. For these purposes, the paper employs a cointegration test with a regime shift and observes the long-run coefficients before and after the regime shift. The findings support the presence of the EKC. The findings also indicate that renewable energy consumption has negative effects on CO₂ emissions, while these effects are greater when the share of renewable energy consumption in total energy consumption is higher in the USA. Theoretical and practical implications for these findings are discussed.

Herein, activated carbon (AC) and carbon nanotubes (CNTs) were synthesised from potato peel waste (PPW). Different ACs were synthesised via two activation steps: firstly, with phosphoric acid (designated PP) and then using potassium hydroxide (designated PK). The AC produced after the two activation steps showed a surface area as high as 833 m² g⁻¹ with a pore volume of 0.44 cm³ g⁻¹, where the raw material of PPW showed a surface area < 4 m² g⁻¹. This can help aid and facilitate the concept of the circular economy by effectively up-cycling and valorising waste lignocellulosic biomass such as potato peel waste to high surface area AC and subsequently, multi-walled carbon nanotubes (MWCNTs). Consequently, MWCNTs were prepared from the produced AC by mixing it with the nitrogen-based material melamine and iron precursor, iron (III) oxalate hexahydrate. This produced hydrophilic multi-wall carbon nanotubes (MWCNTs) with a water contact angle of θ = 14.97 °. Both AC and CNT materials were used in heavy metal removal (HMR) where the maximum lead absorption was observed for sample PK with a 84% removal capacity after the first hour of testing. This result signifies that the synthesis of these up-cycled materials can have applications in areas such as wastewater treatment or other conventional AC/CNT end uses with a rapid cycle time in a two-fold approach to improve the eco-friendly synthesis of such value-added products and the circular economy from a significant waste stream, i.e., PPW. Graphical abstract .

Thallium as a highly toxic metal element has been listed as one of priority drinking water contaminants. In this study, manganese oxide nanoparticles were synthesized through a simple hydrothermal method and applied for the removal of thallium(I). The adsorbent was composed of numerous needle-like nanorods and had an average volume diameter of 230 nm after heat-drying procedure. The crystal form of adsorbent was determined as α-MnO₂. The adsorbent exhibited a much faster adsorption rate than most of previously reported adsorbent, achieving over 66.4% of equilibrium adsorption capacity in the first 10 min. The adsorption process was found to be highly affected by solution pH and higher than 100 mg/g of adsorption capacity could be obtained in a wide pH range of 6.0–10.0. The isotherm study indicated that the adsorption of Tl(I) on the adsorbent was favorable and governed by a chemisorption process, with the maximum adsorption capacity of 505.5 mg/g at pH 7.0. The adsorption process was confirmed to be thermodynamically spontaneous and endothermic. The presence of Na⁺, K⁺, Mg²⁺, Ca²⁺, and Cu²⁺ cations had certain negative effects on the uptake of Tl(I). Based on the batch experiments and XPS analysis, the deprotonated hydroxyl groups that bonded to manganese atoms worked as the binding sites for the effective removal of Tl(I) ions and no redox reaction occurred during the adsorption process.

This study aims to investigate the dynamic relationship between renewable and non-renewable energies, CO₂ intensity and economic growth for the period of 1990–2016 using a case study of Myanmar. Autoregressive distributed lag, dynamic OLS, fully modified OLS and Gregory–Hansen co-integration are applied to analyse a time series dataset over the specified time period. The analysis shows that total energy use plays an insignificant role in promoting economic growth. However, decomposition analysis reveals that only renewable energy use significantly promotes, whereas non-renewable energy negatively influences, economic growth. Furthermore, non-renewable energy use is counterproductive in the presence of technological inefficiency, and the size of the overall labour force fosters economic growth. Overall results are robust under different estimation scenarios, including structural break, endogeneity and mixed order of integration. This study presents a new avenue of knowledge by investigating the role of decomposed energy use and technological efficiency in promoting economic growth in the context of Myanmar. Results emphasise the production and use of renewable energy to achieve sustainable economic development in Myanmar.

An uncertainty in the relationship between aerosol optical depth (AOD) and fine particulate matter (PM₂.₅) comes from the uncertainty of AOD by aerosol models and the estimated surface reflectance, a mismatch in spatiotemporal resolution, integration of AOD and PM₂.₅ data, and data modeling. In this study, an integrated geographically temporally weighted regression (GTWR) and RANdom SAmple Consensus (RANSAC) models, which provide fine goodness-of-fit between observed PM₂.₅ and AOD data, were used for mapping of PM₂.₅ over Taiwan for the year 2014. For this, dark target (DT) AOD observations at 3-km resolution (DT₃K) only for high-quality assurance flag (QA = 3) were obtained from the scientific data set (SDS) “Optical_Depth_Land_And_Ocean”. AOD observations were also obtained from the merged DT and DB (deep blue) product (DTB₃K) which was generated using the simplified merge scheme (SMS), i.e., using an average of the DT and DB highest quality AOD retrievals or the available one. The GTWR model integrated with RANSAC can use the effective sampling and fitting to overcome the estimation problem of AOD-PM₂.₅ with the uncertainty and outliers of observation data. Results showed that the model dealing with spatiotemporal heterogeneity and uncertainty is a powerful tool to infer patterns of PM₂.₅ from a RANSAC subset samples. Moreover, spatial variability and hotspot analysis were applied after PM₂.₅ mapping. The hotspot and spatial variability of PM₂.₅ maps can give us a summary of the spatiotemporal patterns of PM₂.₅ variations.

Suspended solids (SS) and phosphorus (P) losses in rainfall generated runoff can lead to the deterioration of surface water quality. Simulated rainfall experiments were conducted to investigate the effects of rainfall intensity (30, 50, 65, and 100 mm h⁻¹) and land slope (0°, 5°, and 10°) on SS and P losses in runoff from experimental rigs containing bare land soil and soil planted with grass (tall fescue). In addition, total phosphorus (TP), particulate phosphorus (PP), and dissolved phosphorus (DP) losses in runoff were also measured. Results showed that tall fescue could reduce loads of SS by 86–99.5%, PP by 92–98.5%, and TP by 55–89.8% in runoff compared with losses from bare soil; this is due to a combination reduced raindrop kinetic energy at the soil surface, reduced soil erodibility in the presence of plant roots and shoots, and an increase in roughness and consequently reduced overland flow velocity resulting in the trapping of particles. Linear relationships between losses of SS and TP and between TP and PP in runoff were significant (R² > 0.93) in both bare soil and grass. In addition, SS and TP losses increased greatly significantly with rainfall intensity and slope. The influence of rainfall intensity on SS and P losses was greater than the influence of slope. Simple linear regressions were constructed between losses of SS and P, the rainfall intensity (30 to 100 mm h⁻¹), and land slope (0° to 10°). The multiple regression equations of SS and P losses in runoff established in this study can provide a simple predicting approach for estimating the non-point source pollution load of SS and P arising from rainfall.

Litter decomposition is a complex process that is influenced by many different physical, chemical, and biological processes. Environmental variables and leaf litter quality (e.g., nutrient content) are important factors that play a significant role in regulating litter decomposition. In this study, the effects of adding fungi and using different mesh size litter bags on litter (Populus tomentosa Carr. and Salix matsudana Koidz.) decomposition rates and water quality were investigated, and investigate the combination of these factors influences leaf litter decomposition. Dissolved oxygen (DO), chemical oxygen demand (COD), total phosphorus (TP), and ammonia-nitrogen (NH₃-N) were measured during the 112-day experiment. The salix leaf litter (k = 0.045) displayed faster decomposition rates than those of populous leaf litter (k = 0.026). Litter decomposition was initially slow and then accelerated; and by the end of the experiment, the decomposition rate was significantly higher (p = 0.012, p < 0.05) when fungi were added to the treatment process compared to the blank, and litter bags with different mesh sizes did not influence the decomposition rate. The variations in the decomposition rates and nutrient content were influenced by litter quality and a number of environmental factors. The decomposition rate was most influenced by internal factors related to litter quality, including the N/P and C/P ratios of the litter. By quantifying the interact effect of environment and litter nutrient dynamic, to figure out the revetment plant litter decomposition process in a wetland system in biological physical and chemical aspects, which can help us in making the variables that determine decomposition rates important for assessing wetland function.

The extreme temperatures and uneven distribution of rainfall associated with climate change are expected to affect agricultural productivity and food security. A study was conducted to evaluate the impact of climate change on wheat in southeastern regions of Turkey. The CERES-wheat crop simulation model was calibrated and evaluated with data from eight surveyed farms. The four farms were used for calibration and four for evaluation. Climate change scenarios were developed for the middle (2036–2065) and late 21st century (2066–2095) under representative concentration pathways (RCPs 4.5 and 8.5) for study sites in Islahiye and Nurdagi. Model calibration results showed a good agreement between observed and simulated yield with only a 1 to 11% range of error. The model evaluation results showed good fit between observed and simulated values of all parameters with % error ranged from 0.51 to 13.3%. Future climate change projections showed that maximum temperature (Tmax) will increase between 1.6 °C (RCP4.5) and 2.3 °C (RCP8.5), while minimum temperature (Tmin) will increase between 1.0 °C (RCP4.5) and 1.5 °C (RCP8.5) for mid-century. At the end of the century, Tmax is projected to increase from 2 °C (RCP4.5) to 4 °C (RCP8.5) and Tmin from 1.3 °C (RCP4.5) to 3.1 °C (RCP8.5). Climate change impacts results showed that future rise in temperature will reduce wheat yield by 16.3% in mid-century and 16.8% at the end of the century at Islahiye and for Nurdagi, while 13.0% in mid and 14.4% end of the century. The use of climate and crop modeling technique provides useful information in evaluating the climate change impacts and may assist stakeholders to make decisions to overcome the negative impacts in the near and long term.