Plant-based biomass (CFB (carnauba fruit biomass)) obtained from the fruit exocarp of the species Copernicia prunifera (Mill.) H.E. Moore (carnauba) was evaluated for its viability as an adsorbent of potentially toxic metals in aqueous medium. The CFB was characterized by powder X-ray spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and zeta potential to investigate the morphology of the biosorbent and its interaction with water soluble metal ions of Pb and Cd. The biomass presents an amorphous structure, with negative zeta potential (− 2.59 mV), and the presence of functional groups such as O-H, C-O-C, C-H, and C=O. The removal potential of Pb(II) and Cd(II) was performed in a batch system, and monoelement solutions were tested to assess the effects of adsorbent dose and initial metal ion concentration, pH at the point of zero charge (pHPZC), sorption kinetics, and adsorption capacity. The most appropriate adsorbent concentration was 5 g/L, and sorption studies were carried out at pH 5.0 (pHPZC = 4.68), in which the surface of the adsorbent shows negative charges and favors the adsorption of metal ions. Kinetic studies showed that the pseudo-second order model best fit the experimental data, and equilibrium was reached at 120 min of contact time. The experimental sorption capacity (SCₑₓₚ) for Pb and Cd was around 28 and 34 mg/g, respectively, and six different non-linear isotherm models were used to describe the sorption phenomena, among them, four with 2 parameters, i.e., Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (DR), respectively, and two with 3 parameters, namely, SIPS and Hill. The non-linear Temkin and Freundlich isotherm models best fit the experimental data for Pb(II) and Cd(II), respectively. According to the Langmuir model, Qₘₐₓ was 26 mg/g and 58 mg/g for Pb(II) and Cd(II), respectively, indicating the efficiency of CFB as a new alternative to conventional methods for the removal of potentially toxic metals from aqueous medium.

The current water shortage in China is critical. Moreover, the water shortage has become the main bottleneck hindering sustainable economic growth. Against the background of China’s dual control target of total water use and intensity, we choose the Yangtze River Delta (YRD) region as a research object, which encompasses Shanghai, Jiangsu, Zhejiang, and Anhui. Based on the perspective of water-energy-food nexus, we employ the generalized Divisia index method to decompose the change of water use into eight factors, regional economic scale effect, regional energy use scale effect, regional food production effect, regional water technology effect, regional energy technology effect, regional water-energy nexus effect, regional food-energy nexus effect, and regional water technology for food production effect, and analyze the contribution of each driver to identify the key drivers of total water use control. The results showed that the top four influencing factors are GDP, water intensity, energy consumption, and water-energy nexus in the YRD region. Regional economic scale is the first driving factor for increasing water use in the YRD region except for Zhejiang. Water intensity is the primary driving force of water-saving in Zhejiang. Energy consumption is the third driver of increasing water use in Jiangsu and Anhui. The effect of water-energy nexus is the third driving factor that affects the change of water use in Shanghai and Zhejiang. The authorities in the YRD region should vigorously develop water and energy utilization technologies to increase the water intensity and decrease energy consumption. The energy sector should decrease the water use to decrease the water-energy nexus which is also the main driving factor affecting the change of water use.

Passive and semi-passive sulfate-reducing bioreactors (SRBRs) are attracting increasing attention worldwide for the treatment of contaminated mine effluents. This study focuses on the management of post-treatment residues from these bioreactors. The residues of two bioreactors with different medium compositions were studied after they were mixed with different alkaline amendments (25% biomass ash, 30% aluminum red mud, 10% lime kiln dust, or 15% hydroxyapatite). Weathering cell tests showed that aluminum red mud and Bedford lime kiln dust efficiently maintain the leachate at neutral pH (≥ 7.0) and immobilize some metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the post-treatment residues with average dissolved concentrations < 0.5 mg/L for all toxic metals, except for Mn, which are less than 3.2 mg/L. Column tests were also performed on the unamended post-treatment residues under unsaturated, saturated, and immersed conditions. The storage of the post-treatment SRBR residues under saturated and immersed conditions preserved the reducing conditions of the media and the neutrality of the leachate pH and also limited the leaching of metals retained by the bioreactor media.

Chlorophyll-a is a highly measured metric in water quality and plant health monitoring. Current laboratory-based methods exploit spectroscopic techniques and require expensive instrumentation like spectrophotometer or fluorometer. In this work, a rapid approach has been proposed using electrical impedance spectroscopy (EIS) to measure chlorophyll-a that is extracted from lettuce leaves into 95% (v/v) ethanol. Multiple readings of 70 differently concentrated samples were taken, and the corresponding impedances were measured using the proposed EIS system by varying frequency from 1.5 to 7.5 kHz. Pearson coefficient, variance inflation factor (VIF), and backward elimination were used to identify the significant component of the frequency. Finally, a multiple linear regression model with 11 features in the range of 2.3 kHz to 4.7 kHz was chosen based on the lowest root mean square error (RMSE) and mean absolute error (MAE). The results show high index of positive determination of chlorophyll-a with the coefficient of determination being 0.932, RMSE of 1.05 μgL⁻¹, and MAE of 0.904 μgL⁻¹.

The Dawen River Watershed (DRW), an important sub-basin of the Yellow River, has been experiencing substantial climatic and anthropogenic stresses. Identifying how stressors relate to shifts in vegetation growth is critical for maintaining the health and stability of its regional ecosystems. To address this, we constructed a 20-year dataset (1999–2018) reflecting changes in satellite-based normalized difference vegetation index (NDVI), climate variables, and land use in the DRW. We then used time series, principal component, and partial correlation analyses to detect spatial and temporal patterns in vegetation dynamics over time, as well as linkages with temperature, precipitation, and anthropogenic activities. Over 20 years, the DRW exhibited a warming-greening trend and experienced four regime shifts in its climate-vegetation system, roughly centered on 2001, 2006, 2013, and 2016. Both the average and maximum NDVI increased in all seasons, likely due to favorable changes in seasonal climatic conditions. Temperature was the dominant factor promoting vegetative growth in spring, autumn, and throughout the growing season. Precipitation had a considerable positive effect on the average NDVI during the summer. Spatial analyses indicated that 67.94% of the study area exhibited significant increase in NDVI values over time, mainly locating in the mountains and in Dongping County; Significant NDVI decrease was generally located in the urban expansion areas around cities and counties. Land cover types and annual growth cycles appeared to govern spatial patterns and the extent of variation in vegetation growth, followed by land use–related drivers and climate anomalies. These findings offer an insight on appropriate ecological management and climatic adaptation within the Dawen River Watershed.

Climate change mitigation and adaptation are common global challenges, and how to accelerate carbon neutrality and green recovery is a major global issue. Market-oriented emission reduction policy has been widely concerned for its unique advantages, but most of the current market-oriented emission reduction policies are based on the consideration of end-of-pipe governance and lack of effective control of source reduction. Energy quota trading (EQT) is an innovation of an energy-saving and emission reduction system, which is based on the idea of source reduction. However, it is unknown about the evaluation of the effect of the EQT policy from the macro perspective. Based on the related statistical data of energy consumption, combined with the ARIMA model, STIRPAT model, and the synthetic control method (SCM), this paper analyzes the energy consumption distribution in China from 2001 to 2020 and comprehensively evaluates the effect of EQT in the pilots. The results show that: (1) The overall energy consumption in China shows a steady upward trend, and its distribution is unbalanced. (2) In absolute perspective, EQT can realize the “double control” of the total amount and intensity in energy saving and emission reduction, and the intensity control effect is better than the total amount control effect. (3) In relative perspective, EQT can enhance the potential of energy saving and emission reduction in the pilots, in which it needs to take the regional characteristics into account. The policy effect is still significant when eliminating some unobservable factors, which indicate that the policy is effective and can be replicated nationwide. The study comprehensively evaluates the effect of ETS from multiple perspectives, which can effectively avoid the misjudgment of the policy effectiveness caused by the single dimension evaluation, while it can also be used as a reference for the government to perfect the policies of energy management system and emission control system. Furthermore, the development of EQT is an important catalyst for policymakers to coordinate policies to accelerate the achievement of carbon-neutral targets and a more resilient low-carbon development model.

Neonicotinoid insecticides are widely used in agriculture for pest control, but the pesticide residues in environmental and agricultural products were a big threat to the health of non-target organisms. In this study, a new immunochromatographic strip test was established for the rapid detection of imidacloprid residue, a neonicotinoid insecticide, based on up-conversion nanoparticles (UCNPs) coupled with the monoclonal antibody against imidacloprid. Under optimal conditions, the half inhibitory concentration (IC₅₀), detection limit, and the linear range of this strip were 8.37 ng/mL, 0.45 ng/mL, and 0.97–250 ng/mL. The strip test could be completed in 30 min. The average recoveries of imidacloprid spiked in water, Chinese cabbages, cucumber, honey, and tea samples were 70.1~101.8%, with coefficient of variations less than 18.9%. The strip was used to test real samples and verified by UPLC-MS/MS method with the good agreement (R² was 0.9825), indicating this novel strip immunoassay is accurate and reliable.

Malaria is a climate-sensitive infectious disease. Many ecological studies have investigated the independent impacts of ambient temperature on malaria. However, the optimal temperature measures of malaria and its interaction with other meteorological factors on malaria transmission are less understood. This study aims to investigate the effect of ambient temperature and its interactions with relative humidity and rainfall on malaria in Suzhou, a temperate climate city in Anhui Province, China. Weekly malaria and meteorological data from 2005 to 2012 were obtained for Suzhou. A distributed lag nonlinear model was conducted to quantify the effect of different temperature measures on malaria. The best measure was defined as that with the minimum quasi-Akaike information criterion. GeoDetector and Poisson regression models were employed to quantify the interactions of temperature, relative humidity, and rainfall on malaria transmission. A total of 13,382 malaria cases were notified in Suzhou from 2005 to 2012. Each 5 °C rise in average temperature over 10 °C resulted in a 22% (95% CI: 17%, 28%) increase in malaria cases at lag of 4 weeks. In terms of cumulative effects from lag 1 to 8 weeks, each 5 °C increase over 10 °C caused a 175% growth in malaria cases (95% CI: 139%, 216%). Average temperature achieved the best performance in terms of model fitting, followed by minimum temperature, most frequent temperature, and maximum temperature. Temperature had an interactive effect on malaria with relative humidity and rainfall. High temperature together with high relative humidity and high rainfall could accelerate the transmission of malaria. Meteorological factors may affect malaria transmission interactively. The research findings could be helpful in the development of weather-based malaria early warning system, especially in the context of climate change for the prevention of possible malaria resurgence.

The carbonaceous content of rainwater was investigated in samples collected at an urban background site in northern India. Sampling was performed on an event basis during two seasons: pre-monsoon (PM) and monsoon (MN) season covering May–June and July–August, respectively, in 2016. The concentrations of different fractions of water-insoluble organic carbon (WIOC) and elemental carbon (EC) were precisely determined, and the sources of WIOC and EC were also analysed. The result revealed that the average WIOC and EC concentration in rainwater ranged from 0.4 to 52 mgC/L and from 0.1 to 15.3 mgC/L, respectively. The concentrations of WIOC and EC were found to be ~ 9 times and ~ 12 times higher, respectively, in the PM season than MN season. The WIOC/EC ratio indicated higher variation in PM season as compared to that of the MN season, suggesting divergent emission sources during the PM season. The formation of water-insoluble secondary organic carbon (WISOC) has also been identified as one of the causes for the extensive difference in the WIOC/EC ratio in different seasons. Results showed that the WIOC and its fractions were efficiently scavenged through rain. While EC and its fractions were less significantly scavenged, due to its hydrophobicity and fine size. The atmospheric scavenging coefficients of selected carbonaceous components were found significantly correlated with rain intensity (RI) during both the seasons. Higher rain intensity caused greater rates of carbonaceous component wash-out and decreasing concentrations of carbonaceous components in the rain.

The widespread use of pesticides contributes to their existence in the environment. The compounds with photocatalytic activity in environmental matrixes play a significant effect on the photodegradation of pesticides. In order to clear the photolysis effects of the main characteristic inorganic metal elements in the of Panax ginseng field soil on fluazifop-p-butyl, a series of tests were carried out. The obtained results indicated that Mn²⁺ and Sn⁺ exhibited a significant photosensitization on the ultraviolet photodegradation of fluazifop-p-butyl. Also the high content of VO₃– and Mo₇O₂₄⁶– in the photolysis system showed a photoquenching on fluazifop-p-butyl, but the low content is a photosensitive effect. However, in the photolysis system, as the concentration of Co²⁺ and Li⁺ increases, the photoquenching effect on fluazifop-p-butyl becomes obvious, and no photosensitization at any tested concentration of them.