This study was carried out to evaluate the effects of dietary supplementation of aqueous extract of Withania somnifera (W. somnifera) against cadmium chloride–induced toxicity in the Nile tilapia, Oreochromis niloticus. Five experimental groups were designed: group (I) was free from cadmium chloride and W. somnifera and served as a control, group (II) was exposed to 1.775 mg L⁻¹ of cadmium chloride only (which is equivalent to 1/4 96-h LC50), while groups (III), (IV), and (V) were exposed to 1.775 mg cadmium chloride L⁻¹ with co-supplementation of dietary W. somnifera in doses of 1.0, 2.0, and 3.0 mL kg⁻¹ body weight (bwt), respectively. The experiment lasted for 4 weeks. In the second and fourth weeks of the experiment, the following indicators were evaluated: hematological (hemogram and blood protein profile), biochemical (activities of serum liver enzymes, namely alanine transaminase (ALT) and aspartate transaminase (AST)), immunological (immunoglobulin M (IgM), serum lysozyme), and tissue antioxidant changes (malondialdehyde (MDA) levels and activities of catalase (CAT) and superoxide dismutase (SOD)). Additionally, gene expressions of glutathione-S-transferase (GST) in the liver were assessed. At the end of the experiment, all fish in all groups were experimentally challenged with Aeromonas hydrophila and the relative protection survival (RPS) was demonstrated. The results revealed that groups exposed to cadmium chloride toxicity and co-supplemented with dietary aqueous extract of W. somnifera at high doses showed significant ameliorative effects in hemogram parameters, total protein, globulin, IgM, and lysozyme against cadmium chloride–induced toxicity compared to the control group and the group exposed to a sublethal dose of cadmium chloride without co-suplemntation of W. somnifera. The results showed also that groups supplemented orally with W. somnifera at high doses have higher antioxidant activities of CAT and SOD and reduction of MDA formation. Levels of gene expressions of GST in the liver were higher in W. somnifera extract-supplemented groups more than those in the group exposed to cadmium chloride–induced toxicity without W. somnifera supplementation. In addition, the results revealed improved RPS with the dietary supply of W. somnifera extract in high doses. In conclusion, this study showed that the dietary supplementation of W. somnifera extract to diets of O. niloticus could be suggested as an effective way to overcome cadmium chloride–induced toxicity because it improves blood parameters and antioxidants, and it can be used as an immunostimulant against the invading bacterial pathogens.

The complex mixtures of antibiotics and heavy metals are commonly existed in livestock and poultry breeding wastewater. Effective and simultaneous removal of these toxic compounds by microorganisms, especially single strains, remains a considerable challenge. In this study, a novel functional strain SDB4, isolated from duck manure and identified as Bacillus sp., has been shown to possess high removal capabilities for both sulfamethoxazole (SMX) and Zn²⁺. The maximum removal efficiency achieved 73.97% for SMX and 84.06% for Zn²⁺ within 48 h in the single pollution system. It has great potential for eliminating SMX along with Zn²⁺, 78.45% of SMX and 52.91% of Zn²⁺ were removed in the 20 mg·L⁻¹ SMX and 100 mg·L⁻¹ Zn²⁺ binary system. Furthermore, the SMX-biotransformation capability of SDB4 was enhanced at low concentrations of Zn²⁺ (below 100 mg·L⁻¹). The SMX biotransformation and Zn²⁺ adsorption data fitted well with the pseudo-first-order kinetic model, indicating that the two pollutants were in accordance with the same removal rule. N⁴-acetyl-SMX was identified as the main stable transformation product during SMX removal. FTIR analyses revealed that OH, NH₂, C=O, C-N/N-H, and C-O-C played major roles in the adsorption of Zn²⁺. Our study of the dually functioning strain SDB4 provides a potential application for the simultaneous biological removal of antibiotics and heavy metals.

This study deals with the pollution impact of biomedical waste (BMW) generation due to the COVID-19 pandemic at both the global and national levels. This discussion is important in light of clear scientific evidence that, apart from the airborne transmission of the disease, the virus also survives on different surfaces and poses the risk of infection. Moreover, an investigation is conducted on BMW generation in tons/day in India during the COVID-19 period, with implications for future projection. Additionally, a pioneering study was conducted to estimate the usage of facemasks during the COVID-19 pandemic in India. This paper also provides a feasible solution, by adopting a modern perspective, towards managing BMW generated in the context of SARS-CoV-2 at isolation wards and crematoriums. Strategical approaches have been suggested for segregating and safely disposing BMW. The latest availability of disposal facilities is discussed based on source data provided by the Central Pollution Control Board (CPCB), India. Among the many disposal methods, incineration technologies are examined in depth. The impact of existing incineration technology on the environment and human health has been extensively studied. This study suggests strategies for controlling BMW generation during the COVID-19 pandemic.

This study proposes to explore solid waste material (SWM) reuse of the riverway silt and sediment, and examines the impacts of chemical composition on road construction through sensitivity analysis. Considering the characteristics of silt mixture, it is necessary to investigate the modified materials to improve the mechanical feasibility for subgrade filling. In this study, the water content of riverway silt and sediments was found to be important to determine the selection and content of modified materials. Specifically, the riverway silt and sediment with low water content could be improved effectively with 6 to 8% lime. Compared to the original sludge, the improved mixture had better particle size and permeability, and the carrying capacity also grew 2 to 3 times. On the other hand, the reuse of riverway silt and sediment with high water content over 40% was provided with multiple schemes. Among them, the modification scheme of construction waste or garbage slag showed well mechanical properties and environmental benefits in the sensitivity analysis, especially for the high water content sludge modified by the mixture of garbage slag and lime. The California bearing ratio (CBR₂.₅) was 2 to 5 times higher than the original silt, which would promote the reuse of multiple solid wastes in road construction. Finally, this study puts forward engineering measures to prevent heavy metals from polluting the water and soil environment by silt-improved soil roadbeds, and the improved riverway silt and sediment roadbeds were proved to be safe and reliable for the environment during service.

The eutrophication of reservoirs can change the physicochemical parameters of water, thus affecting the migration and transformation of heavy metals. At present, there is insufficient research on the coupling mechanisms between nutrients and heavy metals, especially between heavy metals in suspended particles. In this paper, spatial and temporal distribution characteristics of nutrients dissolved heavy metals, and heavy metals in suspended particles were analyzed in a seasonally stratified reservoir. Combined with the nitrogen and phosphorus biogeochemical process, the coupling mechanisms between heavy metals and nutrients were discussed. The results showed that the Aha Reservoir had temperature and dissolved oxygen stratification in April and July. The reduction and dissolution of Fe and Mn oxide/hydroxide and the resuspension of sediments might result in a simultaneous increase in the concentrations of nutrients, dissolved heavy metals and heavy metals in suspended particles in hypolimnion in July and October. In the presence of dissimilatory iron-reducing bacteria (DRIB), the dissolution of iron-bound phosphorus in sediments and suspended particulate matter (SPM) might lead to the simultaneous release of iron and phosphorus into the water. The dissolution of metal sulfides in the sediments and SPM under the action of dissimilatory nitrate reduction to ammonium (DNRA) bacteria might lead to the simultaneous release of ammonia nitrogen and heavy metals into the water. Due to the coupling between nitrogen and phosphorus and heavy metals, seasonal stratified reservoir may face the risk of periodic simultaneous pollution of eutrophication and heavy metals in summer and autumn. This research provides theoretical support for the treatment of heavy metal and eutrophication combined pollution in karst areas.

Based on the input–output table and considering the terms of import and export trade at the national level, this paper calculates China’s annual direct carbon emissions and total carbon emissions from 2005 to 2015. On the one hand, the actual direct carbon emissions and actual complete carbon emissions at the national level are calculated by MRIO model; on the other hand, according to the 5-year emission reduction targets set in the Eleventh Five-Year Plan and the outline document of the Twelfth Five-Year Plan, the emission reduction targets for each year are determined by equal distribution over the years. Hence, the annual carbon intensity emission reduction targets for 2006–2010 and 2011–2015 can be determined to be 4% and 3.4%, respectively, to calculate the target direct carbon emissions and target goal for complete carbon emissions. The smaller of the two is taken as the total quota. Taking 2015 as an example, the total direct carbon quota and complete carbon quota calculated are 87.87 million tons and 71.85 million tons, respectively, which is the total amount to be allocated for inter-provincial direct carbon quota and inter-provincial complete carbon quota. Findings of the study hold pivotal implications for policy development.

The polymer flooding tertiary oil recovery technology also produces a large amount of polymer-containing produced water while improving oilfield recovery. The direct discharge of polymer-containing produced water without treatment will cause great damage to the ecological environment. Therefore, the efficient degradation of polymer-containing wastewater has become a research hotspot. In this paper, the degradation of polyacrylamide (PAM) solution by AC/Mn + TiO₂ photocatalyst was generated by dielectric barrier discharge (DBD), and the degradation of PAM solution by different PAM solution concentrations, different discharge voltages, and different numbers of AC/Mn + TiO₂ particles was studied. At the same time, the morphologies of PAM before and after DBD reaction were obtained by environmental electron microscope scanner (ESEM), and AC/Mn + TiO₂ was characterized by ESEM and EDS. The results showed that the soluble degradation rate of DBD to polyacrylamide with a concentration of 1000 mg/L was 74%, while that of 5000 mg/L polyacrylamide was only 53%. The degradation rate of PAM solution was improved by 88%, and the nitrogen oxides generated by DBD reaction can rapidly decrease the pH of PAM solution within 30 min; when the discharge was about 180 min, the PAM molecular chain was obviously broken and gradually mineralized to form water and other inorganic substance thing.

In this modern era, the global warming issue has been on the front burner of almost all countries including Malaysia. This study utilizing time series data spanning from 1970 to 2018. To this end, a linear and nonlinear autoregressive distributed lag model was conducted to reveal the foreign direct investment-growth-environment nexus. The conclusion validates the existence of the pollution haven hypothesis in Malaysia. Specifically, the empirical results of the linear autoregressive distributed lag model indicate that foreign direct investment and real gross domestic product have a significant positive impact on CO₂ emission while carbon damage cost and the interaction term of foreign direct investment and carbon damage cost have a negative impact in the long run and short run. To find the asymmetric behavior of the foreign direct investment our study employed a nonlinear autoregressive distributed lag model. The findings confirmed the asymmetry association of foreign direct investment with CO₂ emission. Interestingly, our results of the interaction term in both models are significant with a negative sign that shows the mediating effect of carbon damage cost that converts the positive effect of foreign direct investment on CO₂ emission to negative. Thus, it is vital to reinforce the use of significant regulation as the Malaysian economy opens up to attract more foreign direct investment.

Cefazolin (CFZ) is an antibiotic widely used in veterinary and human medicine that has been detected in high residual levels in the environment and is therefore considered an emerging contaminant. This work evaluated the adsorption of this contaminant by Spectrogel® type C organoclay, in continuous mode using a fixed-bed column. The fluid dynamics and the effect of the CFZ concentration were evaluated. In addition, prior and post-process organoclay were characterized. The continuous system under the conditions of C₀ = 0.3 mmol/L and Q = 0.1 mL/min presented lower values of mass transfer zone (5.88 cm), whereas the system with C₀ = 0.5 mmol/L and Q = 0.1 mL/min achieved higher CFZ adsorption capacity (20 µmol/g). Phenomenological and mass-transfer models were applied to the experimental data. The dual-site diffusion (DualSD) model better described the breakthrough (BTC) data. Furthermore, density functional theory (DFT) calculation was performed at the molecular level to provide a better comprehension of CFZ adsorption.

Taking into account the complicated and multidimensional nature of financial development, this study aims to investigate the impact of overall financial market development, institution development, and their sub-indices on CO₂ emissions. To advance knowledge about the nexus between financial development and CO₂ emissions, four financial market indices (overall financial market development, FM-access, FM-depth, and FM-efficiency) and four financial institution indices (overall financial institution development, FI-access, FI-depth, and FI-efficiency) are used. The study used two-stage system GMM and panel data of developed and emerging countries over the period 2000–2018. The empirical results reveal that the overall financial market development and its sub-indices (FM-access, FM-depth, and FM-efficiency) reduce CO₂ emissions in developed and emerging countries. The results further show that the overall financial institution development and its sub-indices such as FI-access, FI-depth, and FI-efficiency foster the environment quality in developed economies, while these indices impede the environmental quality in emerging economies. The usage of renewable energy is found to be a viable solution to mitigate the CO₂ emissions in both groups of countries. Additionally, policies related to sustainable development are also discussed in the paper.