97 research outputs found
Fabricating robust thin film composite membranes reinforced on woven mesh backing fabric support for pressure assisted and forward osmosis: A dataset
© 2018 The Authors The data presented in this paper are produced as part of the original research article entitled “Thin-film composite membrane on a compacted woven backing fabric for pressure assisted osmosis” (Sahebi et al., 2017). This article describes how to fabricate a defect free membrane for forward osmosis (FO) and pressure assisted osmosis (PAO) on the woven mesh backing fabric support. Casting polymer on backing fabric support may limit the interfacial polyemirization due to wrinkled membrane surface. This paper presents data obtained from two different backing fabrics used as support for fabrication of thin film composite FO membrane. Backing fabric support were woven polyester mesh with different opening size. The data include the characterization of the intrinsic properties of the membrane samples, SEM and their performance under FO process. The structural parameters (S value) of the substrate were computed from thickness and porosity of the substrates. Thin film composite (TFC) membrane achieved a water flux of 8.1 L m2 h−1 in FO process and 37 L m2 h−1 using 0.5 M NaCl as draw solution (DS) and deionised (DI) water as the feed solution (FS) when applied hydraulic pressure was 10 bar
Risk assessment of hot and humid environments through an integrated fuzzy AHP-VIKOR method
Working in hot and humid environments can jeopardize the health and safety of the workers and reduce their efficiency. Different physical, environmental, and human factors can influence the risk level of working in these atmospheres. Therefore, the risk assessment of such atmospheres must be carried out from a holistic point of view. This paper aims to introduce a novel risk assessment and prioritization model, using hybrid AHP and VIKOR methods in a fuzzy environment. The AHP method was adopted to determine the importance (weight) of the risk influencing parameters. Also, the VIKOR as a compromise solution method was applied to rank the different working stations against the risk criteria. Fuzzy set theory was used to handle the inherent ambiguity and vagueness of the data encountered in the evaluation process. Furthermore, the fuzzy TOPSIS was adopted to further represent the efficacy of the proposed model. To demonstrate the applicability of the model, a small size foundry shop was selected as the real case and a sensitivity analysis was performed to confirm the validity of the model. The results revealed that the “Environment” has the most contribution to the risk level of hot environments (WE = 0.615). That is followed by “Temperature” (WDBT = 0.268), “Air velocity” (WAV = 0.170), “Safety training” (WST = 0.161), “Mean radiant intensity” (WMRT = 0.110), “Humidity” (WH = 0.066), “Seniority structure” (WSS = 0.063), “Work intensity” (WWI = 0.058), “PPE” (WPPE = 0.047), “Work nature” (WPPE = 0.034), and “ Work duration” (WT = 0.022), in sub-factors. Using the F-VIKOR method, the “melting furnace” workstation was determined as the compromise solution with the index value of Q = 1
Modification of Chlorella vulgaris carbon with Fe3O4 nanoparticles for tetracycline elimination from aqueous media
Skin rash is one of the most common complications during childhood. Viral agents play an essential role in the development of such symptoms. Present study aims to determine the prevalence and genetic variability of Human Herpesvirus 6 and 7 (HHV-6 and HHV-7) infections and their subtypes in children under 5 years of age with skin rash and negative for rubella and measles. We used serum and throat swap samples from 196 children with skin rash and fever. ELISA and IFA tests were performed to detect antibodies against HHV6/7. Sequencing was performed using Sanger sequencing, and BioEdit and MEGA10 software were used for sequence analysis. According to the results, 66% and 40% of cases were positive for HHV-6 IgM and HHV-7 IgM, respectively. According to the molecular analysis, HHV-6 Nested-PCR was positive in 18% of cases, however, HHV-7 Nested-PCR was positive in 7.7% of cases. On the other hand, HHV-6 IgG and HHV-7 IgG were positive in 91% and 55% of study cases, respectively. For HHV-6, we found some genetic variabilities resulting in antigenic changes compared to reference strains. HHV-7 isolates showed no genetic differentiation and had a stable gene sequence. Based on the results, the detection of some cases of HHV6/7 primary infection and the presence of specific symptoms of roseola in the study population needs continuous evaluation of HHV6/7 frequency and distribution, also genetic variabilities of HHV6. This can pave the way for investigating HHV6 immune evasion and vaccine research and studying the relationship between viral genetic variations and other factors like disease severity. Furthermore, it is necessary to determine the relation between HHV6 genetic changes and latent infection to be considered in possible future vaccines and antiviral drug development
Dataset of the aqueous solution and petrochemical wastewater treatment containing ammonia using low cost and efficient bio-adsorbents
In this dataset, the removal of ammonia from synthetic and real wastewater was studied using the Ziziphus spina-christi activated carbon (ZSAC) and the biochar of Sargassum oligocystum (BSO). Several analyses such as FTIR, SEM, EDS, XRD, and BET were used to determine the physical and surface properties of the adsorbents. The BET analysis showed a high specific surface area of 112.5 and 45.8 m2/g for ZSAC and BSO, respectively. Also, the results indicated that the highest adsorption of ammonia from synthetic wastewater using ZSAC and BSO were obtained 97.9% and 96.2%, at contact time of 80 min, 25 °C, pH 8, and adsorbent dosage of 5 g/L. In addition, the adsorption results of real wastewater from Asaluyeh Pardis Petrochemical Company demonstrated that both adsorbents had the removal efficiency of approximately 90%, which indicates high adsorption efficiency using two adsorbents. Moreover, equilibrium studies showed that the adsorption process of ammonia from wastewater using both adsorbents follows the Freundlich model and the maximum adsorption capacity using the Langmuir isotherm were calculated to be 25.77 mg/g and 7.46 mg/g for ZSAC and BSO, respectively. Furthermore, the thermodynamic study showed that the adsorption process using the bio-adsorbents was spontaneous and exothermic
Phenol red dye removal from wastewater using TiO2-FSM-16 and Ni-FSM-16 photocatalysts
In this study, the performance of Ni-FSM-16 and TiO2-FSM-16 photocatalysts in phenol red removal was explored. The XRD, FE-SEM, and BET tests were used to characterize the catalysts. All experiments were performed at ambient temperature and under UV (20 W). The parameters including dye concentration (20–80 mg/L), photocatalyst concentration (0–8 g/L), UV exposure duration, and contact time (0–160 min) were optimized using RSM software. BET values of Ni-FSM-16 and TiO2-FSM-16 were 718.63 m2/g and 844.93 m2/g, respectively. TiO2-FSM-16 showed better performance in dye removal than Ni-FSM-16. At pH 3, the maximum dye removal by TiO2-FSM-16/UV and Ni-FSM-16/UV was obtained 87% and 64%, respectively. The positive hole species had the main role in photocatalytic phenol red removal. The reusability study was done for up to 7 cycles, but the catalysts can be reused effectively for up to 3 cycles. The synergistic factor for the TiO2-FSM-16 and TiO2-FSM-16/UV processes were calculated to be 1.55 and 2.12, respectively. The dye removal efficiency by TiO2-carbon and Ni-carbon was slightly lower than those obtained by the FSM-16 ones. The TiO2-FSM-16 and Ni-FSM-16 catalysts had a suitable surface and acceptable efficiency in phenol red removal. © 2023 The Author
MIL-101(Cr)-cobalt ferrite magnetic nanocomposite: synthesis, characterization and applications for the sonocatalytic degradation of organic dye pollutants
In this study, for the first time, a novel magnetically recyclable MIL-101(Cr)/CoFe2O4nanocomposite was preparedviaa facile solvothermal method. The morphology, structural, magnetic and optical properties of the nanocomposite were characterizedviafield emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), UV-visible spectroscopy (UV-visible) and BET surface area analysis. Furthermore, the sonocatalytic activity of the MIL-101(Cr)-based magnetic nanocomposite was explored for the degradation of organic dye pollutants such as Rhodamine B (RhB) and methyl orange (MO) under ultrasound irradiation in the presence of H2O2. Under optimized conditions, the degradation efficiency reached 96% for RhB and 88% for MO. The sonocatalytic activity of MIL-101(Cr)/CoFe2O4was almost 12 and 4 times higher than that of the raw MIL-101(Cr) and pure CoFe2O4, respectively. The improved sonocatalytic performance of the as-prepared binary nanocomposite can be attributed to the relatively high specific surface area of MIL-101(Cr) and magnetic property of CoFe2O4, as well as the fast generation and separation of charge carriers (electrons and holes) in MIL-101(Cr) and CoFe2O4. In addition, the trapping tests demonstrated that ·OH radicals are the main active species in the dye degradation process. Moreover, the most influencing factors on the sonocatalytic activity such as the H2O2amount, initial dye concentration and catalyst dosage were investigated. Finally, the nanocomposite was magnetically separated and reused without any observable change in its structure and performance even after four consecutive runs
Design a new photocatalyst of sea sediment/titanate to remove cephalexin antibiotic from aqueous media in the presence of sonication/ultraviolet/hydrogen peroxide: Pathway and mechanism for degradation
The aim of the current study was directed to develop a new sea sediment/titanate photocatalyst to remove cephalexin from aqueous media in the presence of ultraviolet (UV) light, hydrogen peroxide (H2O2), and ultrasonic waves. The influence of furnace temperature (300, 350, 400, and 500 °C), furnace residence time (1, 2, 3, and 4 h), and ratio of sea sediment: titanium (0–6 v: w) on the physicochemical properties and the cephalexin removal by the sea sediment/titanate photocatalyst was explored. The technique of FTIR, SEM/EDX, XRD, BET, BJH, and Mapping was used to determine the physicochemical properties of the generated photocatalyst. The maximum cephalexin removal (94.71%) was obtained at the furnace temperature of 500 °C, the furnace residence time of 2 h, and the sea sediment: titanium ratio of 1:6 (=12 mL TiO2/2 g sea sediment). According to the acquired results, the surface area of the optimized catalyst, namely Cat-500-2-12, was computed to be 52.29 m2/g. The crystallite size of titanium oxide on the optimum photocatalyst was calculated ~17.68 nm. The FTIR test confirmed the presence of C=C, O-H, C=O, C-S, and C-H functional groups in the photocatalyst. The transformation pathway for the degradation of cephalexin by the developed system was drawn. The present investigation showed that the developed technique (sea sediment/titanate-UV-H2O2-ultrasonic) could be used as a promising alternative for attenuating cephalexin from aqueous solutions
Optimization and characterization of zeolite-titanate for ibuprofen elimination by sonication/hydrogen peroxide/ultraviolet activity
In this study, a photo-catalyst of titanium oxide was coated on zeolite by the sol–gel method. The generation of the zeolite-titanate photo-catalyst was optimized at conditions of calcination temperature (300, 350, 400 and 500 °C), calcination time (1, 2, 3, and 4 h), and titanate content (0, 2, 4, 6, and 8 mL). The catalyst was used for ‘Sonication/UV/H2O2″ activity and finally, eliminating ibuprofen. Physicochemical properties of the as-built photo-catalysts for all optimized conditions were determined using FESEM-EDX-mapping, BET, FTIR, and XRD. The highest percentage of ibuprofen removal (98.9%) was obtained at conditions of zeolite to titanium ratio of 1 g: 2 mL, time in the furnace of 1 h, and temperature of the furnace of 350 °C. The optimum photo-catalytic (namely, Cat-350-1-2) had a surface area value of 39 m2/g and a crystalline size of 4.9 nm. The surface area for all photo-catalysts increased after being used for ibuprofen removal, possibly due to ultrasonic waves. The presence of Ti-O, benzene ring, O-Al-O, O-Si-O, C–H, and O–H in the photo-catalysts structure were confirmed. Growing the calcination time resulted in an increase in the crystallinity of titanium dioxide in the photo-catalysts and, ultimately a reduction in the ibuprofen removal. The consumed energy by the developed system was calculated for the presence (0.094 kJ/g) and absence (17.5 kJ/g) of the ultrasonic wave. The degradation pathway and reaction kinetic are also explored and proposed. The results showed that the ultrasonic-UV-activated H2O2-based technique can be applied as an alternative method for ibuprofen removal from aqueous medi
Ozone-assisted photocatalytic degradation of gaseous toluene from waste air stream using silica-functionalized graphene oxide/ZnO coated on fiberglass: performance, intermediates, and mechanistic pathways
The present study focused on the potential of an ozone-assisted photocatalytic process using the catalyst silica-functionalized graphene oxide/ZnO coated on fiberglass (Si-GO/ZnO-FG) in the removal of toluene from waste air stream. Here, a comparative examination was performed in terms of toluene removal efficiency in the photocatalytic process (UV/Si-GO/ZnO-FG) and photocatalytic ozonation (O3/UV/Si-GO/ZnO-FG). The gaseous intermediates resulting from degradation of toluene by different processes were analyzed using GC-MS. The results of this study indicated that with the addition of ozone to the UV/Si-GO/ZnO-FG process, toluene removal increased significantly from 76.18 to 87.8%. The reason for this incremental efficiency can be explained by the fact that with the addition of ozone, the production rate and the extent of hydroxyl radical (OH•) production grow significantly; thereby, more pathways are developed for toluene degradation. The major byproducts in toluene oxidation by photocatalytic and photocatalytic ozonation processes include formic acid, acetic acid, benzyl alcohol, benzaldehyde, p-cresol, hydroquinone, and benzoic acid. Given the intermediates and the dominant oxidants detected in the aforementioned process, the possible toluene degradation pathway by the utilized process was suggested
The permeability and selectivity of nanocomposite membrane of PEBAx 1657/PEI/SiO2 for separation of CO2, N2, O2, CH4 gases: A data set
The poly ether-block-amide (PEBAx)/Poly-ether-imide (PEI)/SiO2 nanocomposite membranes were fabricated using the solution casting method and utilized for separation of N2, O2, CH4, and CO2 gases. The effect of SiO2 nanoparticles loading on permeability and selectivity of gases using the nanocomposite membranes was tested. The data showed that the permeability of the gases increased with increasing SiO2 nanoparticle content. dBy adding SiO2 nanoparticles (10 wt%), the permeability of N2, O2, CH4, and CO2 gases elevated from 0.39, 1, 1.83 and 11.1 to 2.01, 1.95, 2.98 and 19.83 Barrer unit, respectively (at a pressure of 2 Bar). In contrast, with increasing SiO2 content the selectivity of the studied gases decreased. The morphology, crystallinity and the functional groups of the fabricated membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) techniques. The data presented confirm the influence of the nanoparticles on the membrane structure and thus on the permeability and selectivity of the membranes
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