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The purpose of the present study is to evaluate the effects of financial development, human capital, globalization, and renewable energy consumption on ecological and carbon footprint. For this purpose, the data was collected from four countries i.e. Brazil, Russia, India, and China for 20 years (1997–2016). The 20 years panel data collected for these countries was analyzed through "auto-regressive distributed lag" (ARDL). Findings of this study reveal that human capital is a significant positive determinant of environmental degradation in short run and long run while renewable energy consumption is a significant negative determinant of environmental degradation in short run and long run. Findings further reveal that globalization significantly reduces environmental degradation in short run and long run. Furthermore, findings show that the financial development significantly positively affects the environmental degradation in short run and long run. Therefore, renewable energy consumption and globalization are found to be negative predictors of ecological footprint and carbon footprint while human capital and financial development are found to be positive predictors of ecological footprint and carbon footprint. These findings are expected to be great contribution to the literature and practice, as they will help researchers and policymakers to realize the relative importance of energy, educational, economic, and trade policies in determining the environmental degradation. • This study evaluates the effects on ecological and carbon footprint. • 20 years' panel data collected through ARDL. • This finding will help in determining the environmental degradation. [ABSTRACT FROM AUTHOR]

A biocompatible and novelly-defined adsorption membrane for rapid removal of fluoride was prepared. Both adsorption and membrane techniques were used in this research. Al(OH) 3 nanoparticles modified hydroxyapatite (Al-HAP) nanowires were developed and made into Al-HAP membrane. The adsorption data of Al-HAP adsorbent could be well described by Freundlich isotherm model while the adsorption kinetic followed pseudo-second-order model. The maximum of adsorption capacity was 93.84 mg/g when the fluoride concentration was 200 mg/L. The adsorption mechanism was anion exchanges and electrostatic interactions. The contribution rates of HAP nanowires and Al(OH) 3 nanoparticles in fluoride removal were 36.70% and 63.30%, respectively. The fixed-bed column test demonstrate that the Al-HAP was biocompatible and in a good stability during the process of water treatment. The fluoride removal abilities of Al-HAP membrane with 0.3 mm thickness could reach 1568 L/m 2 when fluoride concentrations were 5 mg/L. This study indicated that the Al-HAP membrane could be developed into a very viable technology for highly effective removal of fluoride from drinking water. [ABSTRACT FROM AUTHOR]

A novelly-defined adsorption membrane for rapid removal of fluoride from drinking water was prepared. Both zirconium metal-organic frameworks (Zr-MOFs) adsorbent and membrane with large specific surface area of 740.28 m 2 /g were used for fluoride removal for the first time. For adsorption technique, fluoride adsorption on Zr-MOFs was studied on a batch mode. The adsorption data could be well described by Langmuir isotherm model while the adsorption kinetic followed pseudo-second-order model. The maximum of adsorption capacity was 102.40 mg/g at pH 7.0 when the initial fluoride concentration was 200 mg/L. The FT-IR and XPS analyses of Zr-MOFs revealed that both surface hydroxyl groups and Zr(IV) active sites played important roles in fluoride adsorption process. The as-prepared Zr-MOFs adsorbent was suitable for practical treatment of drinking water and regeneration by sodium hydroxide solution (3 wt%). For membrane experiments, Zr-MOFs membrane supported on Alumina substrate could remove fluoride efficiently through dynamic filtration. The fluoride removal capability of Zr-MOFs membrane depended on flow rate and initial concentration of fluoride. The fluoride removal abilities of Zr-MOFs membrane with 20 μm thickness could reach 5510, 5173, and 4664 L/m 2 when fluoride concentrations were 5, 8 and 10 mg/L, respectively. This study indicated that Zr-MOFs membrane could be developed into a very viable technology for highly effective removal of fluoride from drinking water. [ABSTRACT FROM AUTHOR]