This study aims to examine the impact of economic growth, financial openness, trade openness, and energy intensity on the ecological footprint of BRICS countries for the period 1996–2016 in the framework of the environmental Kuznets curve (EKC). In the research phases, the effects of financial openness and trade openness on ecological footprint were examined both individually and as a whole using three models. The results indicate that the EKC hypothesis is not valid in all BRICS countries. Specifically, the individual results demonstrate that the EKC model using financial openness is valid only for India, while the EKC model using trade openness is valid both for India and South Africa. Furthermore, financial openness has reduced environmental pollution in India and South Africa. Trade openness has reduced environmental pollution in China and India, while it has increased in South Africa. Lastly, energy intensity has increased environmental pollution in all countries except Russia for both models. Overall, policy-makers should develop policies to reduce energy intensity in BRICS countries.

This study examines the relationship between foreign direct investment inflows and economic growth in a carbon function, by incorporating the role of urbanization, and coal consumption as additional variables to avoid omitted variable bias. The different order of integration from the unit root test suggested the adoption of a dynamic autoregressive distributed lag bounds testing procedure. The results confirmed the existence of a long-run equilibrium relationship between the outlined series within the period under investigation, with a high speed of convergence. The ARDL equilibrium relationship shows that coal consumption is the largest emitter of carbon dioxide emissions in both short- (0.77%) and long-run (0.86%). Economic growth was found to escalate CO₂ emission by approximately 0.27% (in the short-run) and 0.19% (in the long-run). The Granger causality test indicates a non-causal effect between FDI inflow and economic expansion in South Africa, which implies that FDI is not a driver of economic advancement. The empirical study shows a bidirectional causal effect between urbanization and foreign direct investment. This suggests that urban development stimulates foreign direct investment in South Africa. The findings reveal a one-way link from GDP to coal consumption, suggesting economic prosperity promotes coal consumption. The study underscores that economic development and the attraction of more economic investments is in part dependent on the conservative policy, development of urban centers through infrastructural improvement, and establishing industrial zones.

In this study, a new adsorbent of silicon-doped magnesium oxide (SMG) was developed for the recovery of nutrients from wastewater. The adsorption conditions including adsorbent dosage, initial solution pH, contact time, coexisting substances, N/P molar ratios, and reaction temperature were investigated. Analysis of field emission scanning electron microscopy-energy dispersive spectrometer (FESEM-DES) and specific surface areas (BET) showed that SMG was a mesoporous adsorbent with SBET of 108.31 m²/g. The recycled sediment (RS) was identified as almost pure struvite via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The recovery efficiencies of SMG reached 43.25% of ammonia nitrogen and 97.31% of phosphate at dosage of 0.3 g/L, initial solution pH of 7.0, contact time of 20 min, and temperature of 298 K. Under the optimal reaction conditions, the maximum adsorption capacities of SMG were 170.93 mg/g of ammonia nitrogen and 420.89 mg/g of phosphate at N/P molar ratio of 1.5:1. Coexisting humic acid (HA), calcium (Ca²⁺), acetic acid (AA), and ferric ions (Fe³⁺) in nutrient solution hindered the struvite ordered precipitation. The adsorption process followed pseudo-second-order and Elovich kinetic models and was well described by both the Langmuir and Freundlich isotherms at room temperature. All results indicated that the most likely mechanism of nutrients recovery from wastewater was chemical precipitation and proved that SMG was a high-efficiency adsorption material in a wide pH range of 3.0–9.0 for simultaneous recovery of nutrients from wastewater.

In this study, mature seeds of Zea mays (Malka 16) were irrigated with untreated and UASB-treated wastewater with combination of 50% textile and 50% sewage at hydraulic retention times (HRTs) of 0, 5, 10, and 15 h. Four other treatments diluted with distilled water (DW) were also evaluated. Eight-week analysis of irrigation revealed very small differences in the results of plant biomass and growth parameters of control and those irrigated with 15 h (HRT) treatments. The values of both types of water were observed as chlorophyll a and b contents, 5.9, 3.4, vs 5.5, 3.1 mg g⁻¹, total chlorophyll 9.4 vs 8.8 mg g⁻¹, carotenoids 9.5 vs 8.7 mg g⁻¹, spad values 61.4 vs 56.3, net photosynthetic rate (A) 15.6 vs 14.5 μmol m⁻² S⁻¹, transpiration rate (E) 3.98 vs 3.8 μmol m⁻² S⁻¹, stomatal conductance 5.9 vs 5.8 μmol m⁻² S⁻¹, water use efficiency 10.3 vs 9.7 mmol Cmm⁻¹ H₂O, electrolyte leakage 115 vs 98% and total soluble proteins 385 vs 354 in leaves and 260 vs 231 g⁻¹ FW in roots. While this stress enhanced H₂O₂ 92 vs 115 and 195 vs 224 Units g⁻¹, MDA 6.8 vs 9.1 and 5.9 vs 8.3 Units g⁻¹, activities of enzymatic antioxidants SOD 25 vs 63 and 54 vs 63 Units g⁻¹, POD 1170 vs 1310 and 570 vs 650 Units g⁻¹, CAT 570 vs 820 and 880 vs 1040 Units g⁻¹, and APX 235 vs 278 and 134 vs 187 Units g⁻¹ in leaves and roots, respectively. Heavy metals (Cd, Cr, Cu, and Zn) in such plants were mostly within or about permissible limits of NEQS. The results obtained were more close to that of control. This practice may lead to clean environment and its reuse shall also reduce the stress on fresh water. Early researches transpire a little work done on the reuse of UASB-treated textile wastewater with co substrate, for irrigation purpose.

The fluidity of arsenic (As) in soil used for rice cultivation under flooding conditions is the main reason for its high accumulation in rice, which poses a serious threat to human’s health. Biochar can immobilize heavy metal (for example lead) of soil because of the strong binding of heavy metals to the inner biochar particles. We conducted a pot experiment to evaluate the effects of biochar (BC) and Fe-Mn-Ce oxide–modified biochar composites (FMCBCs) on the morphology, As accumulation, and grain quality of rice grown in As-contaminated soils. The biochar and FMCBC treatments significantly increased the dry weight of roots, stems, leaves, and rice grains grown in As-contaminated soil (P < 0.05). The As concentration in different parts of rice was significantly lower with treatment FMCBC₃₋₂ (BC, Fe, Mn, and Ce weight ratio of 24:2:3:10) than with the BC and control (no BC) treatments. The application of FMCBC₃₋₂ maximized the yield and quality of rice grains: rice grain yields were 61.45–68.41% higher over control and the proportion of essential amino acids in the rice grains was 31.01–44.62%. The application of FMCBCs also increased the concentration of Fe-Mn plaques, which prevent the uptake of As by rice, thereby mitigating the toxic effects of As-contaminated soil on rice. In summary, Fe-Mn-Ce oxide–modified BC composites fixed As, reducing its fluidity and the As concentration in rice. Our results show that FMCBC₃ could play an important role in reducing As accumulation and increasing the grain yield and quality of rice, thus ensuring food safety in regions contaminated with As.

By collecting daily data on measles cases, air pollutants, and meteorological data from 2005 to 2009 in Chengguan District of Lanzhou City, semi-parametric generalized additive model (GAM) was used to quantitatively study the impact of air pollutants and meteorological factors on daily measles cases. The results showed that air pollutants and meteorological factors had effect on the number of daily measles cases, and there was a certain lag effect. Except for SO₂ and relative humidity, other factors showed statistically significant associations with daily measles cases: NO₂ lag 6 days, PM₁₀ and maximum temperature lag 5 days, minimum temperature and average temperature and average air pressure lag 4 days, visibility, and wind speed lag 3 days had the greatest impact on the number of daily measles cases. Under the optimum lag conditions, the number of daily measles cases increased by 15.1%, 17.6%, 7.0%, 116.6%, 98.6%, 85.7%, and 14.4% with the increase of 1 IQR in SO₂, NO₂, PM₁₀, maximum temperature, minimum temperature, average temperature, and wind speed; with the increase of 1 IQR in average pressure, relative humidity, visibility, and daily measles cases decreased by 12.8%, 9.7%, and 13.1%, respectively. And different factors showed different seasonal effects. The effects of SO₂ and temperature factors on daily measles cases were greater in spring and winter, but PM₁₀ in summer.

At first, naked TiO₂ was prepared by sol-gel method. Silver nitrate and thiourea were respectively used as silver source and sulfur source added to form a TiO₂ sol and Ag₂S polymer blend system. Then, the properties of Ag₂S-TiO₂ was one-step synthesized and investigated by photocatalytic experiment and material characterization. According to the characterization results, Ag₂S-TiO₂ is anatase with a band gap of 3.14 eV, a specific surface area of 39.80 m²/g, and an average pore diameter of 3.56 nm. The results of photocatalytic experiments show that Ag₂S-TiO₂ can efficiently remove ethyl paraben within 2 h. Quenching experiments show that both •OH and photogenerated holes have a large effect on photocatalytic performance.

Nanoscale zero-valent iron (nZVI) was prepared and used as a heterogeneous Fenton-like catalyst for the degradation of nuclear-grade cationic exchange resin. The properties of nZVI before and after reaction were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) surface area analysis. The results showed that nZVI–H₂O₂ system exhibited the enhanced degradation of cationic resins, compared with Fe²⁺–H₂O₂, Cu⁰–H₂O₂, and Fe⁰/Cu⁰–H₂O₂ systems. The effects of initial temperature, nZVI dose, and H₂O₂ concentration were studied, and the higher temperature and nZVI dose with relatively low H₂O₂ concentration brought faster degradation rate. The degradation of cationic resins followed the pseudo-first-order kinetics with the apparent activation energy of 53.29 kJ/mol. According to the experimental and calculated infrared and UV-visible spectra, the carbon skeleton of cationic resins was broken with the detachment of benzene ring and the desulfonation of resin polymer by hydroxyl radicals (•OH), generating long-chain alkenes. These intermediates were further oxidized through the hydroxyl substitution, hydrogen abstraction, ring cleavage, or carbonylation reactions, finally forming carboxylic acids remained in solution.

Street dust and soil samples were collected from three study areas in Jinhua, China: a commercial area and two urban districts. The concentrations of nickel (Ni), lead (Pb), copper (Cu), cadmium (Cd), and particularly zinc (Zn) in street dust exceeded soil background values and Chinese soil screening safe levels in some areas. Zn and Cd concentrations in street dust appeared to pose health concerns in the majority of sample sites, but their levels in soils were noticeably lower, indicating possible contamination from atmospheric deposition. Of the three areas, the most severe pollution occurred in Jindong (JD) District. Practically all the samples from JD District showed contamination to some degree. Based on pollution indices, the contamination levels of heavy metals among the studied sites were ranked in the following descending order: JD District > commercial area (CA) > Wucheng District. Source metal identification assessment revealed that the majority of metals in street dust from Jinhua were significantly related to industrial and traffic activities. Health risk assessment was performed based on the US-Environmental Protection Agency model, and the results showed that virtually, no health risk existed from exposure to individual metals in dust particles. However, the noncarcinogenic risk exponentially increased through exposure to various metals in dust. Thus, the majority of hazard index values surpassed the acceptable level. For carcinogens, the carcinogenic risks of each metal did not supersede the acceptable range for children. This observation demonstrates that although the carcinogenic risk is acceptable, the noncarcinogenic risk remains a genuine health concern for local children.

Understanding the controlling factor of groundwater quality could certainly enhance the promotion of the sustainable development of groundwater resources. In fact, during the last decades, the coastal aquifer of Mahdia–Ksour Essef that belongs to the semi-arid region of Tunisia has been marked by an increase of groundwater extraction for irrigation and water for drinking. Moreover, the water quality shows deterioration due to the septic tanks and intensive agricultural activities especially in the coastal side of the aquifer. This study aimed to (1) assess the water quality using Piper Diagram, Box Plot, ions scatter diagrams, (2) understand the processes of mineralization acquisition in the aquifer, and (3) identify the chemical processes and their spatial distribution in the study area. To solve these objectives, the multivariate statistical analysis such as multiple correspondence analysis and hydrochemical analysis was performed. Accordingly, two types of groundwater are identified through the hydrochemical analysis as Na-Cl and Ca-SO₄. According to multiple correspondence analysis, three water groups are determined (G1, G2, and G3). Indeed, the groundwater quality is controlled by the water-rock interactions and affected by the seawater intrusion and agricultural activities. The generated results would be helpful to provide a managing model highlighting the threatened locations. It could be considered as a basis for future monitoring programs that aspire to protect water resources.