In this experimental study on self-compacting concrete (SCC), the Manufactured sand (M-sand) and Fly ash (FA) were utilised for partial replacement of Natural sand (N-sand) and Ordinary Portland Cement (OPC), respectively. N-sand was partially replaced by M-sand at various percentage levels, after the dose of FA in the mix was optimised. In terms of compressive strength, the optimum replacement level of OPC by FA was 20%, whilst for replacement of N-sand by M-sand it was 50%. Two types of mixes were prepared to compare the macro and micro level properties of SCC, i.e., SCC-I (100%OPC + 100%N-sand) and SCC-II (80%OPC + 20%FA + 50%N-sand + 50%M-sand). The characteristics of fresh concrete mixes were determined using Slump flow, T₅₀ time, V-funnel, L-box, U-box, and J-ring tests. After 28 days of curing in tap water, both types of specimens were exposed to a solution of ammonium sulphate [(NH₄)₂SO₄] containing sulphate salt concentration of 2.0 g/l for 360 days to test their durability. Loss in compressive strength, weight change, sorptivity, and micro-structural changes (XRD, SEM, and EDS) all were evaluated for up to 360 days. It was found that the use of FA and M-sand in concrete makes it more environmental-friendly and durable, as well as have better performance in a sulphate environment.

A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward chemical procedure. The as-obtained nanomaterial (Imo-nZVI) was characterized using transmission electron microscopy (TEM), electrophoretic mobility (EM), and vibrating sample magnetometry (VSM). The prepared Imo-nZVI was superparamagnetic at room temperature and could be easily separated by an external magnetic field. Sorption batch experiments were performed for single- and multicomponent systems and demonstrated that Hg²⁺ and Pb²⁺ could be quantitatively adsorbed at pH 3.0. For multicomponent systems, maximum adsorption capacities of 61.6 mg·g⁻¹ and 76.9 mg·g⁻¹ were obtained for Hg²⁺ and Pb²⁺ respectively. It was observed that the functional groups in Imo-nZVI interact preferentially with analytes according to the Misono softness parameter. The higher performance of Imo-nZVI compared with Imo and nZVI is related to the increased number of adsorption sites in the functionalized nanomaterial. The sorption equilibrium data obeyed the Langmuir model, while kinetic studies demonstrated that the sorption processes of Hg²⁺ and Pb²⁺ followed the pseudo-second-order model. This study suggests that the Imo-nZVI composite can be used as a promising sorbent to provide a simple and fast separation method to remove Hg and Pb ions from contaminated water.

Acrylamide (AA) exposure is associated with a range of adverse health effects. However, whether AA exposure is related to hypertension in adolescents remains unclear. The associations of blood hemoglobin biomarkers of AA (HbAA) and its metabolite glycidamide (HbGA) with hypertension risk, diastolic blood pressure (DBP), and systolic blood pressure (SBP) were evaluated by multivariate logistic regression and linear regression. We identified a potential positive association between blood HbGA and hypertension risk in adolescent females (OR 1.81, 95% CI 1.00–3.30; P for trend = 0.022); however, there was no correlation in the non-linear model (P = 0.831). In the sex-stratified linear models, blood HbGA level had a strong positive association with SBP in adolescent females (beta 0.84, 95% CI 0.13–1.55, P = 0.020). Mechanistically, a one-unit increase in blood HbGA (ln transformed) was associated with a 2.83 mg/dL increase in total cholesterol (TC) among females in the fully adjusted model. Mediation analysis showed that TC mediated 24.15% of the association between blood HbGA level and the prevalence of hypertension in females. The present results provide epidemiological evidence that exposure to AA, mainly its metabolite glycidamide, is positively associated with the prevalence of hypertension or increased SBP in adolescent females.

In China, innovation plays an important role in achieving economic development with green growth, but innovation activities are inhibited by the spread of haze pollution (also called smog). Using panel data on 265 cities in China at the prefectural level from 2001 to 2018, this paper investigates the relationship between haze pollution and urban innovation. The conclusions are as follows. First, haze pollution has a significant inhibitory effect on urban innovation. After we consider endogeneity, eliminate extreme values, replace variables, and incorporate spatial correlation, we find that the negative impact of haze pollution on urban innovation still exists. Second, the channels through which haze pollution affects urban innovation are mainly attributed to production efficiency, willingness to consume, and entrepreneurial activity. Third, the inhibitory effect of haze pollution on innovation has a spatial spillover effect. Fourth, among the different regions in China, the most serious inhibitory effect of haze pollution on innovation is in the central region, while that of the eastern and western regions is insignificant. Moreover, across diverse Chinese cities, the significant inhibitory effects of haze pollution on innovation are mainly in cities that are abundant in natural resource. Accordingly, the efficient management of haze pollution is a critical prerequisite and effective guarantee for increasing urban innovation, such as promoting clean energy, strengthening technological innovation, and improving human capital.

Leachate produced from hazardous waste landfills has been observed to exhibit very complex characteristics including the presence of a high amount of refractory organics and toxic elements which make it unfit for conventional treatment. This study is focused on the characterization and treatability of “hazardous waste landfill leachate” through electrocoagulation for the reduction of chemical oxygen demand (COD). Effect of different operating parameters, such as electrode material, interelectrode distance (IED), current density (CD), and electrolysis time (ET), has also been studied. For galvanized iron (GI) electrodes, a significant reduction in phenolic compounds, cadmium, lead, and zinc concentration was observed and more than 80% reduction in COD and color was achieved on a bench-scale reactor for a CD value of 41.64 A/cm² at IED of 1.5 cm and for ET equating to 240 min. Substantiated by experimental results and statistical analysis like ANOVA and post hoc analysis, it appears that electrocoagulation is a proficient technology for the treatment of hazardous waste landfill leachate which has a huge potential for further research.

This research focuses on the health risks caused by heavy metal (HM) environmental pollution. Soil, water, corn, rice, and patients’ hair samples from Daping Village, Yunnan Province, China, were analyzed for seven selected HMs. Geoaccumulation index (Igₑₒ), pollution indexes (PI), and the Nemerow integrated pollution index (PN) were used to evaluate pollution levels. We employed principal component analysis (PCA), correlation analysis (CA), and spatial distribution to identify the source and distribution characteristics of HMs in soil. Health risks of HMs and exposure pathways were accessed by calculating the hazard quotient (HQ) and hazard index (HI). The Igₑₒ, PI, and PN results show that cadmium (Cd) and arsenic (As) pollution is severe in soil, while other pollution is relatively little. PCA, CA, and spatial distribution show that HMs may be derived from black shale weathering and enrichment. Residents’ drinking water is relatively safe. Arsenic is the element most threatening to local residents (HI = 3.8). Soil (HI = 3.55) ingestion and plant (HI = 1.67) ingestion are the primary exposure pathways to HMs. This unusual disease may be caused by children’s relatively low immunity and long-term exposure to As. We must enhance the protection of children and encourage avoiding soil contact as much as possible. Our results highlight the importance of investigating HM pollution from geological sources and blocking potential exposure pathways.

Grazing animals act as a bioindicator to study the heavy metal status in the pasture lands because excessive amount of toxic metals in the animal diet either disturb their normal activity or deposit the contaminants into their tissues. The aim of this study was to appraise the chromium status in soil and pasture crops with respect to the nutritional requirement of grazing animals. Three different sites were selected to collect soil, forages, and animal samples from District Jhang. All the samples were processed through atomic absorption spectrophotometer to analyze the chromium concentration in them. Chromium concentration was varied as 0.703–4.20 mg/kg in soil, 0.45–2.85 mg/kg in forages, and 0.588–2.37 mg/kg in all collected animal samples. Both the soil and forage samples displayed the maximum chromium concentration in the Capparis decidua, whereas animal samples revealed maximum concentration in animal blood. Results of pollution load index (0.078 to 0.463 mg/kg) exhibited that all the sample values are less than unity while enrichment factor (1.57–8.25mg/kg) showed that significant level of chromium is enriched in these sites. The maximum value of daily intake (0.0007–0.0055mg/kg/day) and health risk index (0.0004–0.00370055mg/kg/day) was observed in the buffalo that feed on the Capparis decidua. Bio-concentration factor (0.398–2.09mg/kg) value was the maximum in the Medicago sativa. It is concluded that all the animal samples showed chromium concentration beyond their standards. Thus, proper measures should be taken to reduce the metal contamination in these areas that ultimately lessen the availability of toxic metals to grazing animals.

This article estimates the ties between green fiscal policies and energy efficiency in COVID-19 era. For this purpose, data envelopment analysis (DEA) approach is considered and applied. The study findings show that green fiscal policies, such as public supports and tax rebates, have significant role in reducing energy poverty of different international countries by advancing energy efficiency. Therefore, a panel data ranging from 2010 to 2020 is used. Our findings indicate that the aggregate degree of green fiscal policies help to decline energy poverty. Renewable energy companies had larger series of net fiscal competence and size efficiency, and their levels of energy efficiency were greater than 0.457%, with the 16% effect of current public supports and 11% effect of taxation rebates supported to diminish energy poverty with 29.7% in different international economies. This is a positive effect by green fiscal policies. The study also presented policy implications suggesting effectively implementing green fiscal policies for more efficient carbon reduction and making climate change supportive for peoples in post COVID-19 period.

In this work, four kinds of covalent organic framework (COF) materials (TpPa-1, TpBD, TpDT, and TFBBD) with different pore sizes or functional groups were synthesized by an ultrasonic method for the adsorption of five sulfonamides. Optimization experiments regarding the adsorption time, vortex speed, and pH were carried out to improve adsorption efficiency. In addition, kinetic and thermodynamic experiments were conducted to explore the adsorption mechanism of the sulfonamides on the different COFs. The adsorption processes of the five sulfonamides on the four COFs fit the pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Additionally, pore filling, hydrogen bond interactions, and electrostatic attraction were found to be the main adsorption mechanisms.

Fluopyram is a novel broad-spectrum fungicide with nematocidal activity, and as an extensively used pesticide, it could cause toxicity in nontarget organisms. The aim of this study was to explore the efficiency of five horizontal subsurface flow (HSF) constructed wetlands (CWs) to remove fluopyram from rinsing water produced during the cleaning of pesticide spraying equipment. Four CWs, namely WG-R, WG-R-P, WG-C, and WG-U, contained fine gravel as porous media. WG-R and WG-R-P were planted with Phragmites australis, WG-C with Typha latifolia, and WG-U was left unplanted. Bioaugmentation with plant growth-promoting rhizobacteria was conducted in WG-R-P unit. The fifth unit (WGZ-R) planted with Phragmites australis and contained gravel and zeolite as porous media. All of CWs were loaded on a daily basis from December 2019 to January 2021 with water fortified with fluopyram. The removal rate follows the pattern of WG-R-P (70.67%) > WGZ-R (62.06%) > WG-C (59.98%) > WG-R (36.10%) > WG-U (25.09%). The most important parameters affecting the fluopyram removal were bioaugmentation, zeolite presence in porous media, and plant species. The WG-R-P unit showed higher fluopyram removal in comparison to the WG-R (increase about 96%), the zeolite increased the fluopyram removal by 72%, and the WG-C unit showed 66% higher fluopyram removal than the WG-R unit.