Olefin plant spent caustic wastewater treatment using electro-Fenton technique

The aim of this research was to reduce the chemical oxygen demand (COD) and sulfide from a spent caustic wastewater using electron-Fenton technique. The experiments were applied to evaluate the effect of several parameters such as pH, reaction time, current density mA/cm², H₂O₂/Spent Caustic Wastewater (SCW) (ml/l), H₂O₂/Fe²⁺ molar ratio on the performance of the process. The response surface methodology (RSM) was applied to minimize the number of runs and investigate the optimum operating conditions. Five independent variables were carefully considered and optimized in this paper. The optimum conditions were found at pH of 2.96, reaction time of 70.67 min, current density of 58.85 mA/cm², H₂O₂/SCW of 1.59 ml/l, H₂O₂/Fe²⁺ molar ratio of 3.47 for 81.20 COD removal while the optimum conditions were found at pH of 2.87, reaction time of 65.52 min, current density of 55.47 mA/cm², H₂O₂/SCW of 1.38 ml/l, H₂O₂/Fe²⁺ molar ratio of 3.21 for 99.9998 sulfide removal.     

Adhesion Molecule Targeted Therapy for Non-Infectious Uveitis

Non-infectious uveitis (NIU) is an inflammatory eye disease initiated via CD4⁺ T-cell activation and transmigration, resulting in focal retinal tissue damage and visual acuity disturbance. Cell adhesion molecules (CAMs) are activated during the inflammatory process to facilitate the leukocyte recruitment cascade. Our review focused on CAM-targeted therapies in experimental autoimmune uveitis (EAU) and NIU. We concluded that CAM-based therapies have demonstrated benefits for controlling EAU severity with decreases in immune cell migration, especially via ICAM-1/LFA-1 and VCAM-1/VLA-4 (integrin) pathways. P-selectin and E-selectin are more involved specifically in uveitis related to vasculitis. These therapies have potential clinical applications for the development of a more personalized and specific treatment. Localized therapies are the future direction to avoid serious systemic side effects.     

Economic growth, CO2 emissions, and fossil fuels consumption in Iran

Environmental issues have attracted renewed interest and more attention during recent years due to climatic problems associated with the increased levels of pollution and the deterioration of the environmental quality as a result of increased human activity. This paper investigates the causal relationships between economic growth, carbon emission, and fossil fuels consumption, using the relatively new time series technique known as the Toda-Yamamoto method for Iran during the period 1967–2007. Total fossil fuels, petroleum products, and natural gas consumption are used as three proxies for energy consumption. Empirical results suggest a unidirectional Granger causality running from GDP and two proxies of energy consumption (petroleum products and natural gas consumption) to carbon emissions, and no Granger causality running from total fossil fuels consumption to carbon emissions in the long run. The results also show that carbon emissions, petroleum products, and total fossil fuels consumption do not lead to economic growth, though gas consumption does.     

Synthesis,Characterization, and Properties of Sulfonated CNT-Doped Poly(aniline-co-carbazole)-PVA Conductive Films

Conductive flexible films are successfully synthesized from polyvinyl alcohol matrix and poly(aniline-co-carbazole) charge carrier. To improve the mechanical properties of polyvinyl alcohol and promote charge transition in the conductive copolymer, dual purpose sulfonated multiwall carbon nanotube is added. Conductivity is enhanced via sulfonic acid protonic dopant and mechanical property is increased by its hexagonal nanorods. Nanocomposites are prepared by adding 0.025, 0.050, and 0.075 g of carbon nanotube which is added at 1%, 3%, and 5% loads to the polymer matrix. Films are characterized by infrared, UV–vis, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. Conductivity is measured by the four-probe technique and mechanical property is assessed through tensile tests and dynamic mechanic thermal analysis. A 5 × 10⁻⁶ S cm⁻¹ conductivity and 116 MPa tensile strength are recorded for the conductive film with optimum dopant/nanocomposite loads. The electrochemical property and corrosion resistance are studied by cyclic voltammetry and Tafel curves, respectively. The conductive films show an increase in corrosion potential and a decrease in corrosion current referring to a reliable corrosion protection film. The water uptake and contact angle of the films are measured to be 157% and 80.1° respectively to confirm its required hydrophilic property.     

Novel carbon‐nanotube‐based organogels as candidates for oil recovery

A simple method for synthesis of novel organogels based on multiwalled carbon nanotubes (MWCNTs) is reported. Three classes of organogels were synthesized by crosslinking polymerization of dodecyl methacrylate with various weight percentages of 1,4‐butanediol dimethacrylate, vinyl‐group‐modified MWCNTs or pristine MWCNTs in the presence of 2,2‐azoisobutyronitrile as initiator. In this reaction, the carbon nanotubes (CNTs) served simultaneously as an adsorbent, a comonomer and a crosslinking agent. The oil‐absorbent containing CNTs showed much higher swelling capacity in oil and organic solvents compared with that without CNTs. Therefore, CNT‐based organogels can be introduced as a promising candidate for environmental protection and oil recovery. © 2012 Society of Chemical Industry     

Synthesis of sulfur nanoparticles-loaded alumina as a low-cost sorbent for the preconcentration of nickel from real samples

This study reports a simple method for the synthesis of α-sulfur-nanoparticles-loaded alumina as a reliable kind of sorbents in solid-phase extraction (SPE) methods for the preconcentration and determination of trace levels of Ni(II) from real samples. The most important advantage of this technique is not using the ligand as a complexing agent and hence the disadvantages of other SPE methods have been avoided. The calibration graph was linear over the range of 0.66–100 µg/L and the relative standard deviation (RSD) of 1.98% at 50 µg/L was obtained. The limit of detection (LOD) and preconcentration factor (PF) were obtained as 0.22 µg/L and 250, respectively. The maximum adsorption capacity of the adsorbent was found to be 18 mg/g for Ni(II).     

Functional Insights into Silymarin as an Antiviral Agent against Enterovirus A71 (EV-A71)

Enterovirus A71 (EV-A71) is a major neurovirulent agent capable of causing severe hand, foot and mouth disease (HFMD) associated with neurological complications and death. Currently, no FDA-approved antiviral is available for the treatment of EV-A71 infections. The flavonoid silymarin was shown to exert virucidal effects, but the binding site on the capsid was unknown. In this study, the ligand interacting site of silymarin was determined in silico and validated in vitro. Moreover, the potential of EV-A71 to develop resistance against silymarin was further evaluated. Molecular docking of silymarin with the capsid of EV-A71 indicated that silymarin binds to viral protein 1 (VP1) of EV-A71, specifically at the GH loop of VP1. The in vitro binding of silymarin with VP1 of EV-A71 was validated using recombinant VP1 through ELISA competitive binding assay. Continuous passaging of EV-A71 in the presence of silymarin resulted in the emergence of a mutant carrying a substitution of isoleucine by threonine (I97T) at position 97 of the BC loop of EV-A71. The mutation was speculated to overcome the inhibitory effects of silymarin. This study provides functional insights into the underlying mechanism of EV-A71 inhibition by silymarin, but warrants further in vivo evaluation before being developed as a potential therapeutic agent.     

Application of response surface methodology for simultaneous carbon and nitrogen (SND) removal from dairy wastewater in batch systems

The application of batch systems to the direct treatment of dairy wastewater was investigated. Batch experiments were conducted to study the organics removal and simultaneous nitrification and denitrification (SND) process. The experiment was conducted by varying four independent parameters (mixed liquor suspended solids, chemical oxygen demand [COD]/N ratio, aeration time and cycling time), using a central composite design under response surface methodology. The process responses of five dependent parameters (COD, Total kjehldahl nitrogen (TKN), NO₃ ^?, effluent NO₃ ^? and effluent total nitrogen) were studied, and in each case, the percentage removal in batch runs was determined with each process displayed in contour plots. Finally, after optimizing the process conditions, the best treatment of dairy wastewater under optimized conditions was established and the responses were shown. This study shows that microbial granules cultivated under the alternating aerobic/anaerobic conditions in batch systems could efficiently remove organic carbon and convert all the ammonium to nitrogen gas.