Enhancing removal and recovery of magnesium from aqueous solutions by using modified zeolite and bentonite and process optimization

Seyed Saeid Hosseini,Mohammad Amin Alaei Shahmirzadi,Nicolas Raymond Tan 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.12

Natural and modified zeolite and bentonite are investigated and characterized for extraction of magnesium from aqueous solutions. Magnesium removals as high as 85.21% and 81.73% were achieved by calcined bentonite and microwave radiated zeolite, respectively. The effects of various operational parameters were studied and optimized using selected isotherms. Maximum Mg (II) adsorption capacities of 26.24 and 35.67mg·g−1 were obtained on pristine and calcined bentonites, respectively. Thermodynamic studies suggest that magnesium adsorption on natural bentonite is spontaneous and endothermic (9.13 kj·mol−1). Also, desorption study of natural bentonite demonstrates that HNO3 is more effective by offering 89.11% desorption than other desorptive counterparts.

Fabrication, tuning and performance analysis of polyacrylonitrile (PAN)-derived microfiltration membranes for bacteria removal from drinking water

Seyed Saeid Hosseini,Hadi Khodadadi,Bita Bakhshi 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

Removal of bacterial contaminations from water using advanced technologies is one of the essential steps in improving human health. The present study’s aim was to develop high performance microfiltration membranes from polyacrylonitrile (PAN) for bacteria removal from drinking water. The characteristics and performance of membranes were tuned through exploring the variation of prominent fabrication and operating parameters. The findings reveal that increasing PAN concentration in dope and addition of citric acid were successful in tailoring membrane microstructure. Bacteria rejection in modified membranes improved by exhibiting high log removal values (LRV) ranging from 3.92 (99.87%) to 5.57 (99.99%) while permeate fluxes were in the range of 35.83-58.62 L·m2·h1. The trends are explained by taking into account the structural characteristics of bacterial strains. Exploring the effect of operating parameters on the performance of membranes revealed that increase in feed concentration from 103 to 107 cfu·ml1 improved membrane rejection. The largest rejection (5.57) was observed toward Staphylococcus aureus at feed concentration of 107 cfu·ml1. Similarly, rejection improved upon reducing operating pressure from 3.5 to 1.5 bar. Also, shifting of feed pH to 7.4 and 9.4 enhanced membrane rejection to as high as 4.60 and 5.66 toward E. coli and Staphylococcus aureus, respectively. This was attributed to the zeta potential and isoelectric point values of the membranes and involved strains. Overall, the findings revealed that the developed PAN membranes are more effective in removal of gram-positive strains and their rejection is strongly dependent on the peptidoglycan layer of strains.

Gas permeation and separation in asymmetric hollow fiber membrane permeators: Mathematical modeling, sensitivity analysis and optimization

Seyed Saeid Hosseini,Javad Aminian Dehkordi,Prodip Kumar Kundu 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.11

Mathematical modeling is useful for analysis of process design and performance and is widely used for membrane separation and other important technologies in the energy sector. This study presents the results of our investigations on the mathematical modeling and optimization of hollow fiber membrane permeators specifically used for air separation as well as natural gas purification. The governing equations and mathematical models are developed based on the consideration of ideal and non-ideal conditions often involved in the separation of gas mixtures using membrane permeators. The influence and consequences of adoption of two distinct numerical methods for solving governing equations are investigated in details. The results obtained by using the models as well as the effect of numerical method type are examined and compared to the experimental data. The findings highlight the important role of the solution method on the validity and accuracy of the models. Moreover, the effect of variations in the operating conditions and physical geometries of the membrane are investigated through comprehensive sensitivity analysis. Accordingly, a set of optimal input parameters is determined using an appropriate statistical method. The findings provide useful information for the design and development of high performance membrane permeators and processes particularly in the case of binary gas mixtures for energy applications.

Polystyrene derivative-blended nanocomposite membranes for pervaporation dehydration of hydrazine

Seyed Saeid Hosseini,Ehsan Mehralian,Mohammad Hossein Ekbatan,Pei Li 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.3

Hydrazine is an inorganic chemical that has found use in various applications, such as fuel for jets, rockets, missiles and space shuttles. In the present study, polystyrene (PS) based membranes were developed and explored for hydrazine dehydration by pervaporation process. In addition to the separation performance, the physiochemical and morphological characteristics of the membranes were assessed and correlated to the findings. Investigation of the effects of structural and operating parameters revealed that increase in the membrane thickness enhanced selectivity and separation index (PSI) to 18.79 and 61, respectively. In addition, raising feed temperature from 36 o C to 56 o C caused increments in membrane flux, selectivity and PSI. However, increasing feed flow rate only improved water flux. Membranes exhibited reasonable flux and separation performance for the wide range of studied feed compositions. Two modification methods were employed to tailor the characteristics of PS membranes. Blending PS with acrylonitrile butadiene styrene (ABS) led to 27% improvement in total flux while selectivity and PSI reached to as high as 14.3 and 104.6, respectively. Also, nanocomposite membranes containing 2 wt% TiO2 exhibited total flux of 30.9 (g/m2 ·h) and PSI of 175.9.

Enhancing performance of polyacrylonitrile membranes for pervaporation dehydration of ethanol by tailoring morphology and process parameters

Seyed Mohammad Hosseini Nejad,Amir Hossein Mostafavi,Seyed Saeid Hosseini,Haoze Zeng,Lu Shao 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

Development of high performance membranes for ethanol (EtOH) dehydration constitutes one of the main applications of pervaporation technology. In the present study, the properties of membranes derived from PAN were examined for this purpose. Heat treatment and variation of operational parameters were explored as viable strategies for enhancing the process performance. The characteristics of the membranes including morphology, thickness and sorption behavior were investigated in detail to identify their roles. Application of heat treatment with regards to polymer Tg resulted in membranes with distinct morphological and sorption characteristics. Increase in operational temperature was found effective for optimizing the opposing trends of permeate flux and separation factor. The maximum PSI value for the pristine PAN membrane was 5,564.0 g·m−2h−1, which occurred for operation at 50 °C. Also, application of heat treatment led to drop in flux and increase in separation factor by which PSI reached 41.3 kg·m−2h−1, which was 7.5 times than that of pristine PAN membrane. This study demonstrates successful implementation of facile strategies for tuning the characteristics and performance of membranes derived from PAN for efficient dehydration of EtOH via pervaporation process.

Fabrication of modified PVDF membrane in the presence of PVI polymer and evaluation of its performance in the filtration process

Kamran Valizadeh,Amir Heydarinasab,Seyed Saeid Hosseini,Saeed Bazgir 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

In this research, to prepare a polymer membrane with hydrophilic nature that has anti-fouling and antiadhesionproperties first, polyvinyl imidazole (PVI) Polymer was bonded as a surface modifier of fluorinatedpolyvinylidene (PVDF) membranes by Atom transfer radical polymerization (ATRP) method. Therefore, to confirm the chemical changes of the hydrophilic membrane surface such as PVI polymerchain bonding and to investigate the uniform distribution of the polymer in the modified membranepores and surface, experiments such as attenuated general reflectance (ATR-FTIR), nuclear magnetic resonance(H-NMR), Water contact angle (WCA) and scanning electron microscopy (SEM), zeta potential,Atomic force microscopy (AFM) spectroscopy, Thermo-gravimetric analysis (TGA), X-ray energy scattering(EDX), X-ray diffraction (XRD) patterns were performed. The results showed that the WCA for M1membrane was about 83.37 ± 1.77 and Mb6 membrane was about 35.45 ± 1.45, which improved theWCA rate ofMb6 membrane surface by about 57.10%.Therefore, the total Anti-fouling rate and Flux recoveryratio (FRR) and rejection oil rate increased by about 35.2%, 18.65% and 10%, respectively. This studyaimed to investigate the surface modification of membranes prepared with hydrophilic polymer PVI toseparate oil from the oil-in-water emulsion, which is a suitable method and potential approach in controllinglarge-volume oil-in-water emulsion effluents.

Insights into the significance of membrane structure and concentration polarization on the performance of gas separation membrane permeators: Mathematical modeling approach

Javad Aminian Dehkordi,Seyed Saeid Hosseini,Prodip K. Kundu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.67 No.-

This study presents a mathematical modeling approach for developing models based on non-idealconditions related to the membrane structure including porous supporting layer and deformation underpressure. Comparison of thefindings with experimental data reveal the importance of considering theresistance in porous supporting layer though the effect of concentration polarization in the permeatestream could be neglected. Investigations on deformation offibers under pressure ascertain that at largerfiber inner radius to outer radius ratios, increasing driving force may lead to an initial increase inpermeability. After that, the effects of deformation dominates and thus permeability may be decreased.

Pectin extraction from citron peel: optimization by Box–Behnken response surface design

Bahare Pasandide,Faramarz Khodaiyan,Zeinab Mousavi,Seyed Saeid Hosseini 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.4

In this study, the effect of acidic extraction conditions (time of 30–90 min, temperature of 75–95 C and pH of 1.5–3) on the yield and degree of esterification (DE) of citron peel pectin was investigated applying Box– Behnken design. The highest production yield of pectin (28.31 ± 0.11%) was achieved at extraction time of 90 min, temperature of 95 C and pH of 1.5, as optimal extraction conditions, which was close to the predicted value (29.87%). Under optimum extraction conditions, the DE and the emulsifying activity were 51.33 and 46.2%, respectively. In addition, the emulsions were 93.9 and 93.5 stable at 4 C, 93.7 and 93.1 at 23 C after 1 and 30 days, respectively. The determination of flow behavior showed that the pectin solutions had a Newtonian behavior at low concentrations (\1.0% w/v), while this behavior was changed to pseudoplastic with increasing concentration.

Investigating the effect of dianhydride type and pyrolysis condition on the gas separation performance of membranes derived from blended polyimides through statistical analysis

Vahid Pirouzfar,Mohammad Reza Omidkhah,Abdolsamad Zarringhalam Moghaddam,Seyed Saeid Hosseini 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.3

In this study, properly designed experiments are utilized to improve and optimize the main parametersincluding the selection of precursors with different molecular structures, blend composition ofprecursors and conditions of carbonization. Optimum conditions are met for UIP-R/PBI, at blendcomposition of 94% and pyrolysis temperature of 620 ℃ at 10-7 Torr. Under such conditions, the modelestimated permeability of CH4 and CO2 equal to 26.7 and 310 Barrer, while measured selectivityresponses of CO2/CH4 is 77.5, respectively. As a result, greater values of separation efficiency are achievedin the range of 0.88–0.97 polyimide content in these blends.