Red mud is a solid waste of bauxite processing by Bayer process which involves caustic digestion of Al-containing mineral for alumina production. The global inventory of red mud waste reached an estimated amount of 4 billion tons in 2015, increasing at an approximate rate of 120 million tons per year. Therefore, its management is becoming a global environmental issue for the protection of environment, and the need for awareness in this regard is becoming crucial. Although red mud is not considered as a hazardous material in many countries, its high alkalinity and fine particle size may pose significant environmental threat, and it is found to be an interesting material for environmental remediation purposes due to rich iron content. This paper provides a review of possible remedial applications of red mud in various environmental compartments. Modification of red mud creates novel opportunities for cost-effective and efficient removal of metal ions, inorganic anions, dyes, and phenols from wastewater and acid mine drainage. Re-vegetation of red mud disposal sites, treatment of metal-contaminated acidic soils presents the usefulness of this material but less research has been done so far to investigate its use in the stabilization of polluted sediments. On the other hand, leaching and eco-toxicological tests have also revealed that red mud does not pose high toxicity to the environment making it suitable for the treatment of contaminated media. Nevertheless, neutralization of red mud is recommended for its safe disposal and secure application in any environmental media.

A novel porous coordination polymer adsorbent (BTCA-P-Cu-CP) based on a piperazine(P) as a ligand and 1,2,4,5-benzenetetracarboxylic acid (BTCA) as a linker was synthesized and magnetized to form magnetic porous coordination polymer (BTCA-P-Cu-MCP). Fourier transform infrared (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope(FESEM), energy-dispersive X-ray spectroscopy(EDS), CHN, and Brunauer–Emmett–Teller(BET) analysis were used to characterize the synthesized adsorbent. BTCA-P-Cu-MCP was used for removal and preconcentration of Pb(II) ions from environmental water samples prior to flame atomic absorption spectrometry(FAAS) analysis. The maximum adsorption capacity of BTCA-P-Cu-MCP was 582 mg g⁻¹. Adsorption isotherm, kinetic, and thermodynamic parameters were investigated for Pb(II) ions adsorption. Magnetic solid phase extraction (MSPE) method was used for preconcentration of Pb(II) ions and the parameters influencing the preconcentration process have been examined. The linearity range of proposed method was 0.1–100 μg L⁻¹ with a preconcentration factor of 100. The limits of detection and limits of quantification for lead were 0.03 μg L⁻¹ and 0.11 μg L⁻¹, respectively. The intra-day (n = 7) and inter-day (n = 3) relative standard deviations (RSDs) were 1.54 and 3.43% respectively. The recoveries from 94.75 ± 4 to 100.93 ± 1.9% were obtained for rapid extraction of trace levels of Pb(II) ions in different water samples. The results showed that the BTCA-P-Cu-MCP was steady and effective adsorbent for the decontamination and preconcentration of lead ions from the aqueous environment.

For the last three decades, both China and India are considered as the largest emerging market economies in the world. Both of these economies play an essential role in the global economy in terms of economic output and CO₂ emissions. Hence, these countries are expected to play an important role in setting up environmental and sustainable development policies. Therefore, our paper aims to examine the role of natural gas and renewable energy consumptions on CO₂ emissions and economic growth during 1965–2016 within a multivariate framework. The autoregressive distributed lag bounds testing approach to cointegration and vector error correction model (VECM) is employed to explore the long-run and causal nexus among the natural gas consumption, renewable energy consumption, coal and petroleum consumption, CO₂ emissions, and economic growth, respectively. The empirical results show existence of long-run equilibrium association among the variables. The Granger causality results indicate that the short-run bidirectional causality between renewable energy consumption and economic growth in India, while no causality is found between these two variables in China. However, natural gas consumption causes economic growth in China whereas no causality is confirmed in India in the short-run. The findings further suggest that there is long-run bidirectional causality among the considered variables in both countries. Our paper addresses several important policy implications.

Current economic policy planning places much emphasis on balancing development and environmental protection. Hence, it is important to determine the drivers of environment pollution from the theoretical, scientific, and policymaking aspects in the context of continuous economic growth. This paper investigates the factors affecting per capita CO₂ emissions in 30 provinces in Iran from 2009 to 2014 with emphasis on spatial spillover effects using the Spatial Durbin Model. The findings show that per capita CO₂ emissions are positively and significantly affected by per capita GDP, industrialization, and urbanization but negatively affected by changes in population. The results of the spatial section of the model indicate that both the more and the less-polluted provinces tend to cluster together, indicating positive spatial dependence for CO₂ emissions in the provinces. Also, the spatial spillover of per capita GDP and the growth of urbanization have a negative and significant effect on per capita CO₂ emissions in the provinces, while the spatial effect of changes in population is significant but positive. In other words, the economic development and rise in urbanization in one province are the results of changes in pollution levels in neighboring provinces.

One of the most common compounds in pesticide formulations, plastics, and papers is 4-nonylphenol (4-NP). It is contained in agricultural, industrial, and wastewater effluents, which when discharged into surface waters affect aquatic fauna. Therefore, the present study aimed to use Biomphalaria alexandrina snails to evaluate the chronic toxicity of 4-NP. Its concentrations in collected water samples from Giza Governorate ranged from 400 to 1600 μg/l. Based on these environmentally relevant concentrations, laboratory experiments were carried out using standard 4-NP to investigate the effect of three concentrations; namely 400, 750, and 1600 μg/l. Survival rate of the exposed snails to 4-NP concentrations was affected after 4 weeks. Reproduction of the exposed snails to 4-NP concentrations was lower than that of the control at 30 °C, while the exposed snails to 400 μg/l of 4-NP showed maximum reproduction at 15 °C. The lowest hatchability percentage was recorded with egg masses laid by the exposed snails to 400 and 1600 μg/l of 4-NP at 15 and 30 °C, respectively. Furthermore, the results showed fluctuated levels of progesterone, estradiol, and testosterone depending upon the concentration and the temperature, which played a key role in determining the degree of 4-NP toxicity.

Vermicompost, recommended inorganic fertiliser, vermiwash and their combinations were used in the present study to know their impact on the germination, growth, yield, oil content and nutritional status in seeds of two varieties of Linum usitatissimum L. LC-54 and LC-2063. Eight treatments, in 48 plots with three replicates, were studied and compared with control. Application of vermicompost enhanced growth and yield in both varieties of Linum. Vermicompost modulated the ratio of ω-3 and ω-6 fatty acids in seeds of Linseed. Growing degree days (GDD) indicated the significantly shortened of crop life cycle with vermiwash. Vermiwash particularly increased the yield indices. Fatty acid profile through GC-FID showed the increase in polyunsaturated fatty acids (ƩPUFA), monounsaturated fatty acids (ƩMUFA) and saturated fatty acids (ƩSFA) with Integrated Nutrient Management (INM). Different effects on nutritional status of LC-54 and LC-2063 seeds can be attributed to their unique genotypes. INM proved to be nutritionally balanced strategy with enhanced yield leading to better soil health. INM can be hypothesised as a transitional step to the organic agriculture after the green revolution, when compared with recommended inorganic fertiliser treatment and control. In terms of oil yield, highest oil content 34.85% and 33.67% was obtained with Integrated Nutrient Management in both the varieties, whereas treatments with vermicompost and vermiwash produced modulated and most suited ratio of omega-3 and omega-6 in Linseed seeds.

According a wide range of relevant literature, the emulsion liquid membrane technique (ELM) is considered an efficient method to separate and recover organic and inorganic contaminants that could otherwise be released into the environment. One important limitation of ELM process concerns the stabilization and de-stabilization of emulsion globules. To address this, over the last few years, a new ELM trend known as the Pickering emulsion liquid membrane (PELM) has been developed. PELM involves nanoparticle concepts to achieve a more stable emulsion for wastewater treatment. In this article, ELM and PELM techniques, preparation methods, characteristics, stabilization methods (i.e., mechanical and ultrasound emulsification), and de-stabilization (i.e., swelling, leakage and coalescence) of the emulsion are reviewed and described. In addition, various parameters that could impact ELM stability, extraction, and recovery, such as emulsification speed and time, surfactant, carrier, internal agent, diluent, stirring speed, internal to membrane ratio, type of organic membrane, and treatment ratio, are also presented and discussed.

With the rapid development of construction industry, consumption of concrete block has increased rapidly in China. As a kind of green building material and resource comprehensive utilization product, autoclaved aerated fly ash and concrete block have better performance in terms of heat preservation, sound insulation, and fire resistance. However, some typical issues are associated with autoclaved aerated fly ash and concrete block production process such as energy and material consumption as well as pollutant emissions. To examine the environmental and economic impacts of its production process is imperative. Choosing 1 m³ of autoclaved aerated fly ash and concrete block product as functional unit and “cradle to gate” as system boundary, a life cycle inventory is developed. The key processes and key materials with significant environmental impact are identified. Results show that the top four environmental impact categories are marine ecotoxicity, freshwater ecotoxicity, freshwater eutrophication, and human toxicity. Key processes are fly ash slurry production, lime grinding, and steam curing processes. These processes account for 46.58%, 26.00%, and 19.62% of the total environmental load respectively. The key materials are cement, lime, and natural gas, which account for 44.91%, 22.79%, and 20.61% respectively of overall environmental impact. Sensitivity analysis shows that the fly ash slurry production should be optimized preferentially, followed by lime grinding and steam curing processes. These findings are helpful to facilitate the sustainable production of autoclaved aerated fly ash and concrete block.

Tricholorethylene (TCE) has been recognized as second common organic pollutant found in groundwater in Taiwan. Several advanced oxidation processes (AOPs) have been applied for TCE removal and photocatalytic is one of promising AOP techniques. In this study, LaFeO₃ is successfully synthesized via sol-gel method and investigated for its photocatalytic oxidation rate toward TCE in water. Experimental results indicate that 95% removal efficiency of TCE can be achieved in aqueous solution with LaFeO₃ (2 g/L) as photocatalyst within 1 h of Xenon lamp illumination. Additionally, the influences of initial TCE concentration, light intensity, photocatalyst loading, and pH value on the TCE removal efficiency are evaluated as well. The highest energy efficiency obtained in this study is 10.8 mg TCE/kWh and the value is higher than those reported in previous studies. Besides, removal mechanisms have been identified and the results indicate that the overall removal efficiency reaches 82%, with adsorption and photolysis accounting for 20% and 39%, respectively.

Attention-deficit hyperactivity disorder (ADHD) of children is one of the most common neurodevelopmental diseases; the etiology remains unclear. We reviewed and meta-analyzed case-control studies to assess the effects of blood lead levels in children on ADHD symptoms. Relevant studies were identified by searching electronic databases. A meta-analysis was performed using the fixed model of Review Manager 5.3 software. Seven relevant studies were identified. The case groups exhibited significant increases in ADHD symptoms [mean difference (MD), 0.59; 95% confidence interval (CI), 0.50–0.68; p < 0.0001]. Subgroup assessment showed that even children with blood lead levels <3 μg/dL exhibited significant increases in ADHD symptoms (MD, 0.47; 95% CI, 0.39–0.56; p < 0.0001). Subgroup assessment also showed that children aged 5–12 years exhibited more significant increases in ADHD symptoms (MD, 1.35; 95% CI, 0.28–2.41; p < 0.0001) than children aged >12 years. Our findings suggest that low blood lead levels may be associated with ADHD symptoms in children. However, caution is needed when interpreting the results because among-study heterogeneity was in play. Primary interventions should focus on children with low blood lead levels.