Industrialization and urbanization process has brought both economic development and a series of environmental problems. Hebei Province is a high haze area and one of the key areas of China’s “Blue Sky Defense” policy. As carbon emission is one of the most important factors causing haze, it is necessary to screen the influencing factors effectively to make quantitative analysis and predict carbon emissions in different degrees of coordination. Faced with the new situation of Beijing-Tianjin-Hebei coordinated development and more environmental constraints, this paper designs a system for predicting carbon emissions in Hebei Province innovatively using the data during 1990–2016. In the first step, 7 influence factors are determined by “graded screening.” Then, this paper improved the traditional support vector machine (SVM) by improved gray wolf optimizer (IGWO), and established IGWO-SVM model. Finally, the carbon emissions in Hebei Province from 2017 to 2025 are predicted under three stages of different cooperative development speed of 7 influence factors by the improved intelligent algorithm model. Based on the forecasting results, this paper put forward some pertinent opinions to provide theoretical basis for formulating relevant policies on carbon emissions in Hebei Province to effectively control carbon emissions from the source.

Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly toxic Cr(VI) based on oxidation. The efficient decomplexation of Cr(III) complexes and simultaneous abatement of Cr with low Cr(VI) accumulation would be desirable in treatment of Cr(III)-complexed wastewater. Here, we found efficient degradation of Cr(III)-EDTA and simultaneous removal of Cr by forming Cr₂O₃ precipitate from simulated solution as well as an electroplating effluent under UV irradiation. The results showed a complete degradation of Cr(III)-EDTA after reaction time of 60 min and 70–80% of TOC mineralization within 180 min as well. About 90% of Cr(III) precipitated as Cr₂O₃ simultaneously, with the residual total Cr below 1.5 mg/L. The degradation of Cr(III)-EDTA was a stepwise de-acetate group process, as proven by the obvious attenuation of peaks related to carboxyl groups and C–C bond from FT-IR spectra of Cr(III)-EDTA and significant mineralization of TOC after UV irradiation. Based on negligible accumulation of Cr(VI) (less than 0.1 mg/L) under N₂-sparged condition, the C-centered radicals from the β-fragmentation of O-centered radicals formed by photo-induced ligand-to-metal charge transfer were responsible for the in situ reduction of intermediate Cr(VI), resulting in the low accumulation of Cr(VI). The addition of 20 mg/L Fe²⁺ was capable of removing the remaining Cr(VI) and total Cr, with Cr(VI) and total Cr less than 0.1 and 1.0 mg/L, respectively. Moreover, the photo-oxidation process combined with Fe²⁺ addition were efficient in removing other Cr(III) complexes, such as Cr(III)-citrate and those from a realistic electroplating effluent. We believe that this study would provide an alternative option for efficient degradation of Cr(III) complexes and simultaneous abatement of Cr from contaminated water.

Electronic waste (E-waste) can be considered as challenging solid waste streams especially in some developing countries, including Iran. Several alternatives for collecting and processing E-waste have been developed and applied throughout the world. In this research, a model was developed according to fuzzy-AHP approach for the evaluation of different alternatives for E-waste’s collection and processing in Tehran, Iran. Three alternatives for processing section (including recycling, exporting, landfilling) and three alternatives for collection section (door-to-door, special event, permanent drop-off) were studied in terms of different economic, social, technical, and environmental criteria. To establish a database in the current research, a questionnaire survey was performed and then the relative importance of each alternative in terms of each criterion was evaluated. The obtained results indicated that in the section of collection and processing of E-waste, permanent drop-off and recycling have the highest priorities among studied alternatives, respectively. Also, economic and environmental criteria were determined as the most significant ones in collection and processing sections, respectively. Furthermore, the developed model can be considered as a practical tool that will help the decision makers to determine the most appropriate E-waste management alternatives when diverse criteria are partially or completely in conflict.

We investigated the trophic transfer potential of CuO-NPs from Artemia salina to Amatitlania nigrofasciata. The Cu uptake was investigated by exposure of the instar II nauplii to 0, 1, 10, and 100 mg/L CuO-NPs for 4 h. Dietborne exposure of fish larvae to CuO-NPs was done for 21 days through feeding with pre-exposed nauplii. Thereafter, all survived fish were fed for 21 more days with non-contaminated nauplii. The results showed that NPs could be taken up by nauplii in a concentration-dependent manner. The highest uptake of Cu by nauplii was found to be 50.5 ± 1.4 mg/g dry weight at 100 mg/L. The copper accumulation in fish larvae increased significantly with increasing Cu content in pre-exposed nauplii to different concentrations of CuO-NPs (p < 0.05). At the end of the depuration phase, although the Cu elimination was significantly higher in fish that were fed with more contaminated nauplii, but the survival rate, average final weight, and length of those larvae was still significantly less than the control group (p < 0.05). The accumulated Cu after the depuration phase in cichlid larvae was 25.4 ± 0.5, 29 ± 8.0, 33.9 ± 9.7, and 42.3 ± 4.0 μg/g dry weight at 0, 1, 10, and 100 mg/L of CuO-NPs-treated Artemia. The current findings indicated the ability of manufactured CuO-NPs to be transferred from one trophic level to the next as assessed in the simple food chain consisting of pre-exposed A. salina and A. nigrofasciata.

Montmorillonite grafted polyacrylic acid composite (GNM) was prepared by using ultraviolet radiation grafting method in this work. The synthesized materials were characterized by XRF, SEM, FTIR, XRD, TG, and XPS. The experimental equilibrium data indicates that the adsorbent is suitable for the Langmuir model and belongs to the pseudo-second-order kinetic model. The entire adsorption process is spontaneous, endothermic, and chaotically enhanced by thermodynamic analysis. The maximum adsorption capacity of La(III) by GNM was 280.54 mg/g at 313.15 K. In addition, the regeneration experiment shows that the adsorbent has good reusability and stable desorption efficiency. This study demonstrates that GNM has high adsorption performance and La(III) adsorption and regeneration capabilities to solve the water pollution caused by rare earth ions and regeneration capabilities for La(III).

Chlorpyrifos (CPF) is a widely used organophosphate insecticide with several harmful effects. N-acetylcysteine (NAC) represents an ideal antixenobiotic; it can directly enter endogenous biochemical processes and is used as adjunctive treatment for psychiatric disorders. We aimed to evaluate the neuroprotective effect of NAC as an antioxidant drug against CPF-induced neurotoxicity in adult male albino rat brains. Twenty-eight male Wister rats were allocated into four groups (n = 7) and were administered the following for 28 days: group I (control group), physiological saline (0.9% NaCl); group II (CPF group), 10 mg/kg body weight (BW) CPF; group III (NAC group), 100 mg/kg BW NAC; and group VI (CPF+NAC group), NAC 1 h before CPF. CPF intoxication resulted in acetylcholinesterase inhibition, reduced glutathione content, and elevated levels of malondialdehyde and nitric oxide, which are oxidative stress biomarkers. CPF also depleted the activity of antioxidant enzymes, superoxide dismutase and catalase, and levels of inflammatory mediators, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β. Levels of vascular endothelial growth factor, Bax, and the proapoptotic caspases-3 also increased, while brain-derived neurotrophic factor level decreased. Additionally, CPF significantly diminished Bcl-2 (an antiapoptotic protein) in rat brain cortical tissue. NAC treatment was found to protect brain tissue by reversing the CPF-induced neurotoxicity. Our results show the antioxidant, antiinflammatory, and antiapoptotic effects of NAC on CPF-induced neurotoxicity in rat brain tissue.

This study applied the logarithmic mean Divisia index (LMDI) model to identify and discuss the main drivers of Pakistan’s CO₂ emissions over the period 1990–2016. The study examined the effects of five factors based on Pakistan’s three main economic sectors while considering the 11 types of fuels consumed in that country. The results showed that the energy structure effect is the greatest driving force of CO₂ emissions in this country, followed by scale effect and economic structure effect. Energy intensity is the main contributor to reducing Pakistan’s carbon emissions throughout the study period. A comparative review at the sectoral level shows that the industrial sector for which coal is the main source of energy supply is the one that contributes the most to CO₂ emissions in Pakistan. Alongside this sector is the tertiary sector, where the transport sub-sector imposes rules of conduct based on a growing Pakistani population. Meanwhile, deforestation would be the main cause of CO₂ emissions from the agricultural sector in Pakistan, as energy consumption in this sector remains very low. Improving energy efficiency through the intensification of clean energy is urgently needed if Pakistan’s environmental goals are to be achieved.

Vegetation is an important factor affecting nutrient enrichment ratio in runoff sediments but few studies have been examined in the effects of different vegetation scenarios on the monthly evolutions of particulate nitrogen (N) and phosphorus (P) loss. In this study, a vegetation correction coefficient was innovatively embedded in a dynamic particulate nutrient loss model to evaluate the monthly trends of particulate N and P loss in a small highly erodible watershed. Results indicate that (i) the monthly sediment yield from June to August 2013 accounted for the dominant percentage in this extreme hydrological year, which was consistent with the monthly trends of rainfall erosivity. The largest monthly sediment yield rate under four different vegetation scenarios all occurred in July with the values of 530.56, 258.09, 579.69, and 370.74 t km⁻². (ii) Particulate N and P loss from April to September changed significantly under different vegetation scenarios, and they were mainly concentrated in June and July 2013; only the N and P loss loads in July accounted for > 70% of annual load. However, the loads in January, February, March, October, November, and December were considered as zero because there was no erosive rainfall during the above 6 months. (iii) The reduction efficiency of particulate N and P loss by scenario 1 was about 1.7 times higher than scenario 3, which shows that forestland in sediment reduction was stronger than grassland and cropland in Zhifanggou Watershed. Results provide the underlying insights needed to guide vegetation reconstruction and soil conservation planning in loess hilly regions.

The objective of the present investigation was to consider the effectiveness of exogenous silicate supplementation in reviving the arsenate imposed alterations on pigment content, Hill activity, photosynthetic parameters, sugar metabolism, polyamine, and ion contents in wheat (Triticum aestivum L. cv. PBW-343) seedlings. Experiments were conducted under different levels of arsenate (0, 25 μM, 50 μM, and 100 μM) in combination with silicate (0, 5 mM) in a hydroponic environment with modified Hoagland’s solution for 21 days to determine the ameliorative role of silicon (Si). Arsenate exposure led to a decline in chlorophyll content by 28% and Hill activity by 30% on an average along with photosynthetic parameters. Activity of starch phosphorylase increased causing a subsequent decrease in starch contents by 26%. Degradation of starch enhanced sugar contents by 61% in the test cultivar. Dose-dependant increments in the activities of carbohydrate metabolizing enzymes viz., sucrose synthase, sucrose phosphate synthase, and acid invertase were also noted. Putrescine content was significantly enhanced along with a consequent decline in spermidine and spermine contents. The macro- and micronutrient contents declined proportionally with arsenate imposition. Conversely, silicate amendments irrespective of all arsenate concentrations brought about considerable alterations in all parameters tested with respect to arsenate treatment alone. Marked improvement in pigment content and Hill activity also improved the gas exchange parameters. Soluble sugar contents decreased and starch contents were enhanced. Increase in polyamine contents improved the ionic balance in the test cultivar as well. This study highlights the potentiality of silicon in ameliorating the ecotoxicological risks associated with arsenic pollution and the probable ability of silicon to offer an approach in mitigating arsenate-induced stress leading to restoration of growth and metabolism in wheat seedlings.

The alginate extraction residue (RES) from the Brazilian Sargassum filipendula was successfully employed as biosorbent in this binary equilibrium study, revealing a greater affinity and selectivity for Cr(III) than for Zn(II). Experimental results also revealed that the process is of endothermic nature and well adjusted by Langmuir–Freundlich binary model. The X-ray photoelectron spectroscopy (XPS) analysis revealed that coordination with hydroxyl groups of RES prevailed in Cr removal, followed by carboxyl-metal complexation. As far as Zn(II) is concerned, ion exchange with carboxylate groups of RES was the largest contributor. Nevertheless, scanning electron microscopy coupled with Fourier transform infrared spectroscopy indicated the participation of sulfate functions in a minor degree.