Thermally induced characterization and modeling of physicochemical, acoustic, rheological, and thermodynamic properties of novel blends of (HEF + AEP) and (HEF + AMP) for CO 2 /H 2 S absorption Abstract CO2 and H2S removal from flue gases is indispensable to be done for protection of environment with respect to global warming as well as clean air. Chemical absorption is one of the most developed and capable techniques for the removal of these sour gases. Among the many solvents, ionic liquids (ILs) are more capable due to their desirable green solvent properties. However, ILs being usually costlier, the blends of ILs and amines are more suggestive for absorption. In the present work, various essential characterization properties such as density, viscosity, sound velocity, and refractive index of two ionic liquid–amine blend systems viz. (1) 2-Hydroxy ethyl ammonium formate (HEF) + 1-(2-aminoethyl) piperazine (AEP) and (2) 2-Hydroxy ethyl ammonium formate (HEF) + 2-Amino-2-methyl-1-propanol (AMP) are reported. The temperature range for which all the measurements were conducted is 298.15 to 333.15 K. For both systems of (HEF + AEP) and (HEF + AMP), HEF mass fractions were varied from 0.2 to 0.8.The density and viscosity results were correlated as a function of temperature and concentration of ionic liquid and amine with Redlich-Kister and Grunberg-Nissan models, respectively. Moreover, feed forward neural network model (ANN) is explored for correlating experimentally determined sound velocity and refractive index data. The measured properties are further analyzed to estimate various thermodynamic as well as transport properties such as diffusivity of CO2/H2S in the (HEF + AEP) and (HEF + AMP), thermal expansion coefficients, and isentropic compressibility, ΔG0, ΔS0, ΔH0, using the available models in the literature.

Correction to: Ginkgo biloba mitigates silver nanoparticles-induced hepatotoxicity in Wistar rats via improvement of mitochondrial biogenesis and antioxidant status The original publication of this paper contains a mistake. The correct image of figure 3 is shown in this paper.

Ameliorative effect of selenium nanoparticles against aluminum chloride-induced hepatorenal toxicity in rats Abstract The present study evaluated the possible ameliorative efficacy of selenium nanoparticles (SeNPs) on AlCl3-induced hepatorenal injury in rats. Animals were randomly divided into four groups (n = 6): group 1, the control; group 2, received SeNPs (0.4 mg/kg b.wt) for 21 days; group 3, injected with three doses of AlCl3 intraperitoneally (30 mg/kg/body weight) every 5 days; group 4, received SeNPs for 7 days prior to AlCl3 and then received SeNPs concurrently with AlCl3 for the following 14 days. It was observed that AlCl3 increased the levels of AST, ALT, ALP, LDH, total bilirubin, creatinine, urea, uric acid, and MDA significantly; as well as the reduction in the levels of GSH, SOD, GPx stores in comparison with the control group. These biochemical alterations were accompanied and confirmed by the lesion appeared in histological sections in addition to the increase in the expression of caspase-3 and the decrease of the Bcl-2expression. Treatment with SeNPs ameliorates the hepatorenal dysfunction, replenishes the endogenous antioxidant system, downregulates the expression of caspase-3, and upregulates the expression of Bcl-2. This hepatorenal ameliorative role may be due to the ability of SeNPs to equilibrate the oxidant/antioxidant system besides its ability to attenuate apoptosis process.

In situ anodic induction of low-valence copper in electro-Fenton system for effective nitrobenzene degradation Abstract To achieve superior advanced oxidation processes (AOPs), transitional state activators are of great significance for the production of active radicals by H2O2, while instability limits their activation efficiency. In this study, density functional theory calculation (DFT) results showed that Cu+ exhibits excellent H2O2 activation performance, with Gibbs free energy change (ΔG) of 33.66 kcal/mol, two times less than that of Cu2+ (77.83 kcal/mol). Meanwhile, an electro-Fenton system using Cu plate as an anode was proposed for in situ generation of Cu+. The released Cu with low-valence state can be well-confined on the surface of the exciting electrode, which was confirmed by X-ray photoelectron spectroscopy (XPS), Raman, and UV-vis spectroscopy. The hydroxyl radicals in this Cu-based electro-Fenton system were determined by the electron spin resonance (ESR). The nitrobenzene degradation ratio was greatly increased by 43.90% with the introduction of the proposed in situ electrochemical Cu+ generation process. Various characterization results indicated that the production of Cu+ was the key factor in the highly efficient Cu-based electro-Fenton reaction.

Optimization and mechanisms of biosorption process of Zn(II) on rape straw powders in aqueous solution Abstract The different part powders of rape straw as adsorbents were performed to remove zinc ions from aqueous solution in this work. The various factors on influencing removal efficiency of Zn(II) were investigated, and the operational conditions were optimized using the Box–Behnken design of response surface methodology (RSM). Under the optimum conditions obtained, the removal rates of Zn(II) were attained to 100.00%, 78.02%, and 17.00% by straw pith core, seedpods, and shell of rape straw, respectively. Equilibrium and kinetic models were applied to evaluate the adsorption behaviors of Zn(II) on the adsorbents. The equilibrium data were best described by the Langmuir isotherm model, which indicated that the adsorption behaviors were favorably monolayer adsorption processes. The biosorption capacities of Zn(II) were 34.66 mg g−1, 36.41 mg g−1, and 36.74 mg g−1 of rape straw pith core; 23.33 mg g−1, 23.85 mg g−1, and 24.30 mg g−1 of seedpods; and 11.19 mg g−1, 11.23 mg g−1, and 11.27 mg g−1 of shell, respectively, at the various temperatures of 20 °C, 30 °C, and 40 °C based on Langmuir isotherm equation. The pseudo-second-order kinetic model was well to determine the adsorption kinetics, which suggested that ion exchange were occurred during adsorption processes of Zn(II). The characteristics of adsorbents before and after adsorption of Zn(II) were measured using the methods of scanning electron microscope (SEM), zeta potential classes, energy dispersive spectrometer (EDS), and Fourier transform infrared spectroscopy (FT-IR), respectively. The results provided evidences for the adsorption mechanisms of Zn(II) including electrostatic attraction, ion exchange, and functional group involvement on the three part powders of rape straw in aqueous water.

Characteristics of cohort studies of long-term exposure to PM 2.5 : a systematic review Abstract This study systematically reviewed all the cohort studies investigating the relationship between long-term exposure to PM2.5 and any health outcome until February 2018. We searched ISI Web of Knowledge, Pubmed, and Scopus databases for peer-reviewed journal research articles published in English. We only extracted the results of the single-pollutant main analysis of each study, excluding the effect modifications and sensitivity analyses. Out of the initial 9523 articles, 203 articles were ultimately included for analysis. Based on the different characteristics of studies such as study design, outcome, exposure assessment method, and statistical model, we calculated the number and relative frequency of analyses with statistically significant and insignificant results. Most of the studies were prospective (84.8%), assessed both genders (66.5%), and focused on a specific age range (86.8%). Most of the articles (78.1%) had used modeling techniques for exposure assessment of cohorts’ participants. Among the total of 317 health outcomes, the most investigated outcomes include mortality due to cardiovascular disease (6.19%), all causes (5.48%), lung cancer (4.00%), ischemic heart disease (3.50%), and non-accidental causes (3.50%). The percentage of analyses with statistically significant results were higher among studies that used prospective design, mortality as the outcome, fixed stations as exposure assessment method, hazard ratio as risk measure, and no covariate adjustment. We can somehow conclude that the choice of right characteristics for cohort studies can make a difference in their results.

Hexavalent chromium adsorption on virgin, biochar, and chemically modified carbons prepared from Phanera vahlii fruit biomass : equilibrium, kinetics, and thermodynamics approach Abstract A novel biosorbent Phanera vahlii fruit biomass (PVF) and its biochar and chemically modified forms were studied for the elimination of Cr(VI) from synthetic solutions. Biosorbents were characterized through BET, FTIR, FESEM, EDX, and TGA technique. The parameters influencing biosorption were optimized and found as pH 2.0, temperature 303 K, initial metal concentration 500 mg/L, and biosorbent dosage 0.5 g/L. The ideal contact time was 180 min for all biosorbents. Freundlich isotherm was found to have good correlation with investigational data, which indicated that biosorption takes place in multiple layer style. Langmuir adsorption isotherm yielded the highest biosorption capacity (Qo) to be 159.1, 225.1, 244.1, and 278.5 mg/g for Phanera vahlii fruit biomass, Phanera vahlii biochar, Phanera vahlii phosphoric acid activated carbon, and Phanera vahlii zinc chloride activated carbon, respectively. Experimental data had good correlation with pseudo-second-order kinetic model fitted. Thermodynamic studies indicated the biosorption process to be spontaneous, stable, and endothermic. Thus, it was concluded that Phanera vahlii fruit biomass and the derived activated carbons are promising biosorbents for adsorption of chromium from aqueous solutions. Graphical abstract

Source apportionment of urban PM 1 in Barcelona during SAPUSS using organic and inorganic components Abstract Source apportionment of atmospheric PM1 is important for air quality control, especially in urban areas where high mass concentrations are often observed. Chemical analysis of molecular inorganic and organic tracer compounds and subsequently data analysis with receptor models give insight on the origin of the PM1 sources. In the present study, four source apportionment approaches were compared with an extended database containing inorganic and organic compounds that were measured during an intensive sampling campaign at urban traffic and urban background sites in Barcelona. Source apportionment of the combined database, containing both inorganic and organic compounds, was compared with more conventional approaches using inorganic and organic databases separately. Traffic emission sources were identified in all models for the two sites. The combined inorganic and organic databases provided higher discrimination capacity of emission sources. It identified aerosols generated by regional recirculation of biomass burning, secondary biogenic organic aerosols, harbor emissions, and specific industrial emissions. In this respect, this approach identified a relevant industrial source situated at NE Barcelona in which a waste incinerator plant, a combined-cycle power plant, and an industrial glass complex are located. Models using both inorganic and organic molecular tracer compounds improve the source apportionment of urban PM.

Roles of surfactants in pressure-driven membrane separation processes: a review Abstract Surfactants widely exist in various kinds of wastewaters which could be treated by pressure-driven membrane separation (PDMS) techniques. Due to the special characteristics of surfactants, they may affect the performance of membrane filtration. Over the last two decades, there are a number of studies on treating wastewaters containing surfactants by PDMS. The current paper gives a review of the roles of surfactants in PDMS processes. The effects of surfactants on membrane performance were discussed via two aspects: influence of surfactants on membrane fouling and enhanced removal of pollutants by surfactants. The characteristics of surfactants in solution and at solid–liquid interface were summarized. Surfactants in membrane filtration processes cause membrane fouling mainly through adsorption, concentration polarization, pore blocking, and cake formation, and fouling degree may be influenced by various factors (feed water composition, membrane properties, and operation conditions). Furthermore, surfactants may also have a positive effect on membrane performance. Enhanced removal of various kinds of pollutants by PDMS in the presence of surfactants has been summarized, and the removal mechanism has been revealed. Based on the current reports, further studies on membrane fouling caused by surfactants and enhanced removal of pollutants by surfactant-aided membrane filtration were also proposed.

As(V) removal using biochar produced from an agricultural waste and prediction of removal efficiency using multiple regression analysis Abstract Arsenic contamination in drinking water is a matter of concern for many countries. An efficient and low-cost solution for this hazard is essentially needed on urgent basis. Therefore, in this study, banana pith (an agricultural waste) was used for biochar production and later it was modified with iron and applied for arsenic adsorption from aqueous solution. Produced biochar was characterized for proximate, ultimate, and surface analyses. Interestingly, after iron impregnation, the surface area of biochar increased (31.59 m2/g) by nearly 8 times. Morphological analysis showed that iron particles firmly held within the pores after impregnation. Arsenate (As(V)) adsorption behavior of iron-impregnated banana pith biochar was evaluated through a batch study by considering various parameters like dose, concentration, pH, temperature, and competing anions. Compared to impregnated biochar, raw biomass and its biochar showed a lesser affinity for arsenate in aqueous solution. The adsorption isotherm of As(V) on banana pith biochar was covered in the temperature range of 298 to 318 K, and kinetic data of adsorption was experimentally generated at 298 K. Langmuir model for the sorption isotherms and pseudo-second-order kinetic model for the sorption kinetics represented the experimental data. The thermodynamic study showed negative Gibb’s free energy (− 46.88 kJ/mol at 298 K, − 48.58 kJ/mol at 308 K, − 50.73 kJ/mol at 318 K) that suggested spontaneity of the adsorption process. Negative enthalpy (ΔH° = − 10.55 kJ/mol) showed exothermic nature of adsorption of arsenic, while negative entropy (ΔS° = 0.123 kJ/mol.K) suggested enthalpy-driven adsorption process. Mechanism of arsenic adsorption onto iron-impregnated banana pith biochar has also been discussed in detail. Based on the experimental observation, a predictive model for arsenate removal has been developed in this study. The findings of the present study elucidated that iron-impregnated banana pith biochar can be used as a low-cost adsorbing material for As(V) from aqueous solutions.