This paper examines the impact of shadow economy and environmental policy stringency on energy consumption and economic growth in the case of China for the period 1993 to 2019. Asymmetric ARDL empirical findings show that positive shocks in shadow economy and environmental policy stringency have a significant and positive impact on energy consumption and economic growth in the long run. However, the negative shocks in shadow economy exert positive and significant impacts on energy consumption and economic growth in the long run, but magnitudes are small compared to positive shocks. The long-run findings report no significant effect of negative shock in environmental policy stringency on energy consumption and economic growth. China should use environmental policy stringency as economic tools to maintain green economic growth and clean energy demand for sustained economic expansion. Policymakers should focus on the inclusion of environmental policy stringency in any future environment strategy.

Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous solutions. The material presented a highly porous texture, a surface area of 938 m² g⁻¹, and certain functional groups, which were key factors to uptake naproxen from effluents. The maximum adsorption capacity predicted by the Langmuir model for naproxen was 176 mg g⁻¹. The thermodynamic study revealed that the adsorption process was endothermic and spontaneous. The linear driving force (LDF) model presented a good statistical adjustment to the experimental decay data. A suitable interaction pathway of naproxen adsorption onto activated carbon was proposed. The adsorbent material was highly efficient to treat a synthetic mixture containing several drugs and salts, reaching 95.63% removal. Last, it was found that the adsorbent can be regenerated up to 7 times using an HCl solution. Overall, the results proved that the activated carbon derived from grape branches could be an effective and sustainable adsorbent to treat wastewaters containing drugs.

The presence of heavy metal and organic pollutants in wastewater effluents, flue gases, and even solid wastes from petrochemical industries renders improper discharges liable to posing threats to the ecological environment and human health. It is beneficial for pollution control to find out the regional distribution of contaminated sites. This study explored the relationship between the petrochemical contaminated areas and natural, socio-economic, and traffic factors. Ten indicators were selected as input variables, and the MaxEnt model was conducted to identify the potentially contaminated areas. Moreover, among these 10 variables, the factors that have the great impact on the results were determined according to the contribution of variables. The results showed that the MaxEnt model performed well with AUC of 0.981 ± 0.004, and 90% of the measured contaminated sites was located in areas with medium and high probability of contamination in the prediction results. The map of potentially contaminated areas indicated that the areas with high probability of contamination were distributed in Yangtze River Delta, Beijing, Tianjin, southern Guangdong, Fujian coastal areas, central Hubei and northeast Hunan, central Sichuan, and southwest Chongqing. The responses of variables presented that high probability of petrochemical contamination tended to appear in cities with developed economy, dense population, and convenient transportation. This study presents a novel way to identify the potentially contaminated areas for petrochemical sites and provides a theoretical basis to formulate future management strategies.

Nurturing pressure and unemployment affect our production and life in many ways. The aim of this study is to examine the potential effects of nurturing pressure and unemployment on global CO₂ emissions, by using the panel data of 77 countries and regions from 1991 to 2020 and a STIRPAT-based theoretical framework. The results show that at the global level, both nurturing pressure and unemployment overall have negative effects on CO₂ emissions. While at the regional level, it becomes a different situation. An increase in nurturing pressure leads to an increase in CO₂ emissions in the Americas and the Middle East and a decrease in CO₂ emissions in Africa, Europe, and Asia–Pacific. Unemployment has a positive effect on CO₂ emissions in the Middle East and a negative effect on CO₂ emissions in Africa, Americas, Europe, and the Asia–Pacific regions. There is no evidence that unemployment has certain effects on CO₂ emissions in the Middle East and the Asia–Pacific regions.

Macroinvertebrate community in the intertidal setup plays an important role in coastal ecosystem functions and biogeochemical cycle. However, different land use pattern may influence on their community structure, diversity, and composition in the coastal ecosystems. Using Van-Veen grab sampler, 60 sediment samples were seasonally collected from mangroves-dominated, aquaculture-dominated, and anthropogenically affected area in the lower intertidal zone of the Kohelia channel of Bangladesh, the Northern Bay of Bengal. We have tasted the variation in sediment properties across three land-use types in this intertidal habitat. To understand the patterns of benthic macroinvertebrate distribution, a neutral community model was applied. Our results showed that community composition and biodiversity of the benthic macroinvertebrate communities varied significantly between mangrove-dominated area with anthropogenically affected areas among the four seasons. The neutral community model revealed that community assembly of benthic macroinvertebrates in the lower intertidal habitats is structured by stochastic processes while sediment properties have significant influence on species distribution and interactions. Results suggested that land-use changes altered sediment properties and could change the diversity and distribution of the macroinvertebrate communities in the lower intertidal habitats.

The applicability of cellulose nanofibrils (CNFs) has received attention due to their attractive properties. This study proposes the functionalization of açai CNFs with copaiba oil and vegetal tannins to produce films with potential for packaging. Bio-based films were evaluated by vapor permeability, colorimetry, and mechanical strength. CNFs were produced by mechanical fibrillation, from suspensions of bleached açai fibers and commercial eucalipytus pulp. Moreover, copaiba oil and vegetal tannin were added to the CNFs to produce films/nanopapers by casting from both suspensions with concentrations of 1% (based on CNF dry mass). The bulk densities of the eucalyptus CNF films were higher (1.126–1.171 g cm⁻³) compared to the açai CNF ones. Films from eucalyptus and açai pulps containing copaiba oil and tannins presented higher Tonset and Tmax, respectively (312 and 370 °C). Films with açaí CNFs functionalized with copaiba oil and tannin showed the lowest permeability value (370 g day⁻¹ m⁻²). Films produced with eucalyptus pulp, and eucalyptus pulp functionalized with copaiba oil highlighted by superior mechanical strength, achieving 133.8 and 121.4 MPa, respectively. The evaluation of colorimetry showed a greater tendency to yellowing for açai films, especially those functionalized with vegetal tannins. Besides the low cost, functionalized vegetal-based nanomaterials could have attractive properties, with potential for application as some kind of packaging, for transporting basic products, such as breads, flours, or products with low moisture content, enabling efficient utilization of forest wastes.

A technique to produce bio-cementation in sandy soil using the microbially induced calcium carbonate precipitation (MICP) process and calcium ions generated from eggshell is presented in this research. This research also focused on the application of S. pasteurii bacteria and L. fusiformis bacteria along with eggshell and calcium chloride cementing chemicals on the strength properties of sand. The experimental variables maintained in this research are bacteria type (S. pasteurii and L. fusiformis), cementing chemical type (eggshell and calcium chloride) and molarity of the cementing chemical (0.25, 0.50, 0.75 and 1.0). The engineering behaviour of bacteria treated sand was estimated by executing the unconfined compression test and permeability test in the laboratory. From the experimental findings, it is identified that the unconfined compressive strength of sand is enhanced and the value is in the range of 650 kPa. In addition to that, the permeability of sand is minimized in the order of two from 6.3 × E⁻³ to 3.2 × E⁻⁵ cm/s. The best improvement of Young’s modulus and calcium carbonate content estimated in this research are 28.9 MPa and 17.9% when the sand is treated with S. pasteurii along 0.50 molarity of eggshell cementing chemical. The experimental findings are validated with the help of microstructural studies of scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). This research showed that bio-cementation technology in the form of S. pasteurii and eggshell can be effectively adopted to enhance the engineering characteristics of sand.

Antibiotic resistance genes (ARGs) widely occur in both anthropogenic and remote environments. Several studies have investigated the distribution of antibiotic resistance in natural environments. However, the occurrence and diversity of ARGs in remote environments at high elevations have not yet been well elucidated. Abundance, diversity, as well as influencing factors of ARGs in different ecosystems on the Qinghai-Tibet Plateau beyond elevation 5,000 m were explored, using high-throughput quantitative PCR. Totally, 197 ARGs and 12 mobile genetic elements (MGEs) were determined with abundances ranging from 3.75 × 10⁶ to 2.39 × 10⁷ and from 2.21 × 10⁴ to 1.62 × 10⁶ copies g⁻¹, respectively. Both the absolute and relative abundances of ARGs in farmland were lower than those in wetland and grassland. The diversity and dominant resistance mechanism of ARG profiles showed obvious differences among these ecosystems. Bacterial communities and MGEs significantly correlated with ARG profiles, while physico-chemical factors showed little impact. The high abundance and strong positive correlation between integron intI-1 and ARGs suggested a high potential horizontal ARG transfer. Based on the results, the Qinghai-Tibet Plateau can be regarded as a considerable ARG gene pool. This study provides insights into the provenance of ARGs at high elevations.

Spatial variations in grain size parameters can reflect river sediment transport patterns and depositional dynamics. Therefore, 22 surficial sediment samples taken from the Heihe River and its cascade reservoirs were analyzed to better understand the impact of cascade reservoir construction on sediment transport patterns in inland rivers in China. The results showed that the longitudinal distribution of sediment grain size in the Heihe River was significantly affected by the influence of the cascade reservoirs. The retention rate in the cascade reservoir of the Heihe River reached 79% (193.53 Mt/year), which caused most of the fine sand to accumulate in the reservoir, and the sediment fining degree reached approximately 50%. However, the water discharged from the dam caused serious erosion of the riverbed and coarsening of the sediment, and the coarsening degree was approximately 500%. The backwater zone of the reservoir was influenced by both backwater and released water, and the coarsening degree of sediment was approximately 101%. Sedimentary environmental analysis revealed that the characteristics of the sediment grain size in an upstream tributary of the Heihe River were more influenced by source material than by hydrodynamic conditions, while the grain size characteristics of the mainstream sediments were controlled mainly by hydrodynamic conditions. The characteristics of sediment transport in different reaches of the Heihe River were studied, and the results may provide references for the operation of cascade reservoirs and the sediment control of reservoirs.

This paper explored the asymmetrical relationships between green and sustainable technology research and environmental sustainability among the BRICS states from 1990 to 2018. The data was analyzed by second- and third-generation economic techniques such as slope heterogeneity and cross-section independence test, unit root test, structural break unit root test, panel cointegration with structural breaks cointegration tests, cross-section autoregressive distributed lags technique, augmented mean group, and Dumitrescu-Hurlin panel causality test. First, the results validated a long-run cointegration among variables. Second, the results showed that renewable energy consumption and positive shocks to green and sustainable technology research are proper to mitigate carbon dioxide emissions (short- and long-run). Third, gross domestic product, foreign direct investment, exports, and negative shocks to green and sustainable technology research increase carbon dioxide emissions. Fourth, the nexus between green and sustainable technology research and carbon dioxide emissions was counter-cyclical during economic expansion and contraction periods. Fifth, the impact of positive shocks to green and sustainable technology research on carbon dioxide emissions was more than the impact of negative shocks to green and sustainable technology research on carbon dioxide emissions.