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In conjunction with the optimality of single-stage reverse osmosis (SRO) system, this work addresses the economic competence of prominent seawater desalination reverse osmosis systems with permeate reprocessing and recycle using differential evolution as global optimization tool. The optimization approach refers to nonlinear programming formulation consisting of mass balances and design specifications as equality constraints and other design specifications as inequality constraints. Further, MATLAB optimization toolbox-based analysis was conducted to compare the obtained solutions with deterministic optimization methods. Among all considered alternatives such as two stages reverse osmosis (TRO) series arrangement with retentate reprocessing and permeate recycle (TRO-TSRR-PR), SRO, TRO series arrangement with permeate bypass and permeate reprocessing and TRO with permeate reprocessing series arrangement processes, TRO-TSRR-RP process configuration has been evaluated to competitive with the SRO process with an optimal cost of 0.9527$/m3obtained with DE-SQP. While the SRO remains the simplest cost-effective system in terms of topological complexity, the TRO-TSRR-PR process has been evaluated to be 5.75% better than the optimal freshwater production cost of SRO process reported in the literature with an optimal decision variable set values [68.51 bar, 7688, 5881.7 m3/h, 259.8 ppm, 2422, 322.9 m3/h and 1764.9 ppm] for [P1F, NM1, WRORF, C1RP, NM2, W2RP, C2RP]. [ABSTRACT FROM PUBLISHER]

This work targets the identification of optimal rate-enhancement technique for the electroless fabrication of silver–ceramic porous membranes. The membranes were fabricated with porous ceramic supports of 4.5 µm and porosity of 19.3% and with alternate electroless plating (ELP) processes including conventional (CEP), sonication (SOEP), and surfactant (SIEP) plating baths. The alternate processes were evaluated based on the process (conversion, plating efficiency (η), average plating rate) and membrane characteristics (percent pore densification (PPD), metal loading index (MLI)), and their combinations (η/(MLI.PPD)). Among alternate processes, SOEP has been evaluated to be the best to yield silver–ceramic membranes. [ABSTRACT FROM PUBLISHER]

Using low-cost clay supports as substrates, ceramic–LTA zeolite composite membranes (Z1–Z4) were fabricated with hydrothermal crystallization. The composite membranes were achieved with variations in the sequential zeolite depositional steps. For Z1–Z4 membranes, various characterization techniques such as thermogravimetric (TG), particle size distribution (PSD), X-ray diffraction (XRD), and field emission scanning electron microscopic (FE-SEM) analysis were applied. For the Z1–Z4 membranes, the pure water permeability, porosity, and average pore size varied from 1.22 × 10−7to 1.19 × 10−8m3/m2s kPa, 30–23%, and 215–76 nm, respectively. For the Z4 membrane, ultrafiltration experiments were conducted at a pH of 2.5 and transmembrane pressure differential of 207 kPa using aqueous bovine serum albumin (BSA) solutions. The optimal flux and rejection correspond to 4.54 × 10−7m3/m2s and 80%, respectively. [ABSTRACT FROM AUTHOR]

This work addresses the effect of palladium solution concentration on combinatorial plating characteristics of surfactant and sonication coupled electroless plating baths for the fabrication of dense palladium films on porous stainless steel substrates. All plating experiments were carried out using palladium solution concentration of 0·005 and 0·01M plating baths with cetyltrimethylammonium bromide surfactant at four critical micelle concentrations and loading ratio of 203 cm² L-1. The evaluated combinatorial plating characteristics include selective conversion, plating efficiency, plating rate, Pd film thickness and per cent pore densification. The enhancement in palladium solution concentration was found to be insignificant to provide better combinatorial plating characteristics, and the plating bath consisting of 0·005M Pd solution concentration has provided 99·98% per cent pore densification with a Pd film thickness of 8·81 mm and plating efficiency of 80·69%. [ABSTRACT FROM AUTHOR]

This work addresses the development and identification of optimal low cost membrane morphologies for bacteria separation applications. Using uniaxial dry compaction method, ceramic membranes (CM1–CM3) were prepared using kaolin, quartz, calcium carbonate, sodium carbonate, boric acid, sodium metasilicate, and poly-vinyl alcohol (PVA) precursors. The fabricated membranes possessed diverse pore morphologies (0.7-4.5 μm average pore size and 39.4–19.3% porosity). Amongst all membranes, the CM3 membrane with wide pore morphology (average pore size of 4.5 μm and porosity of 19.3%) provided the best performance during the direct-flow MF of syntheticEscherichia coli(DH5α strain) solutions. The CM3 membrane provided a trans-membrane flux varying from 1.21 × 10− 2–3.51 × 10−3m3/m2.s after 10 minutes of direct-flow MF for a variation in feed concentrations of 0.004 –14.9 × 106CFU/mL. Corresponding bacterial removal efficiency and log10reduction value (LRV) values varied from 99-99.9999% and 2-6 respectively. Further, various fouling models have been evaluated for their use in measuring flux decline data. The results indicated that both membrane pore morphologies and concentration ofE. colistrains significantly influenced the measured transmembrane flux, fouling index, and separation efficiency. [ABSTRACT FROM PUBLISHER]

This work addresses the preparation and characterization of inexpensive adsorbents for the removal of Ni (II) from aqueous solutions. Activated carbon based adsorbents have been prepared from plant based biomass resources, namely Pineapple stem (Ananas Comosus) and Bamboo Stem (Bambuseae). Adopting phosphoric acid and heat treatment techniques, it has been observed that the bamboo stem activated charcoal (BSAC) and pineapple stem (PS) adsorbents had a BET surface area of 116 and 11.47 m2/g, respectively. FTIR analysis indicated that various surface functional groups (such as C ≡ N stretching, stretching vibration of C = O, –CH3wagging and C–O stretching vibration) contribute towards Ni (II) adsorption. Batch mode adsorption experiments were conducted for these adsorbents in the range of 50–300 mg/L Ni (II) solution concentration, 2–10 pH, 15–300 min. contact time, and 0.02–0.1 g/50 mL dosage. The BSAC adsorbent has been characterized with a metal uptake and %removal of 121.72 mg/g and 92.47, respectively, which corresponds to 45% higher metal uptake than corresponding bamboo based adsorbents presented in the literature. Further experimentation with BSAC enabled to achieve activated charcoal with surface area values similar to that of the commercial activated carbon adsorbent. The bamboo adsorbent has also been evaluated to perform similar to the commercial activated carbon for the removal and recovery of Pd (II) from synthetic electroless plating solutions. Also, a conceptual cost analysis indicated and affirmed towards the potential of the BSAC adsorbents for waste water treatment applications. [ABSTRACT FROM AUTHOR]

Based on a hierarchial methodology, the article presents the comparative efficacy of Vim commercial detergent for the purpose of surfactant enhanced oil recovery of Assam crude oil in Indian reservoirs. Suitable technical and economic indices were defined to explore the economic competence with other surfactants such as sodium dodecyl benzene sulfonate and sodium dodecyl sulfonate. It was evaluated that the detergent formulation provided the following performance characteristics: IC = 13.43 mN/m.g/L surfactant solution, surfactant sustainability index = 3.88 x 10-3 mN/m.$/L surfactant solution, cost ratio = 0.32 - 0.52 $ surfactant/$ crude oil recovered and 14.7-15.1% tertiary recovery with respect to original oil in place. Further ultralow interfacial tension formulations were also achievable with the commercial detergent. [ABSTRACT FROM AUTHOR]

Using the uniaxial compaction method, ceramic disk type microfiltration membranes were fabricated using mixtures of clays to yield membranes M1, M2, and M3. These were obtained with distinct compositions of raw materials at a sintering temperature of 900°C. Membrane characterization was conducted using thermogravimetric analysis (TGA), particle size distribution (PSD), X-ray diffraction (XRD), and scanning electron microscope analysis (SEM). Morphological characterization of these membranes includes the evaluation of average porosity, pore size, mechanical stability, chemical stability, and hydraulic permeance. With varying composition of the raw materials, it is observed that the average porosity and pore size of the membrane varied between 23–30% and 0.45 to 1.30 µm. For all membranes, the flexural strength varied within the range of 10-34 MPa. Chemical stability tests indicate that the membranes are stable in both acidic and basic media. The hydraulic permeance of M1, M2, and M3membranes is about 3.97 × 10−6, 2.34 × 10−6, and 0.37 × 10−6 m3/m2 s kPa, respectively. Further, the performance of these membranes was studied for the microfiltration of synthetic oily wastewater emulsions. Amongst all membranes, membrane, M2performance is satisfactory as it provides oil rejection of 96%, with high permeate flux of 0.65 × 10−4 m3/m2 s at a lower transmembrane pressure differential of 69 kPa for the oil concentration of 200 mg/L. [ABSTRACT FROM AUTHOR]

ABSTRACT This work reports microfiltration (MF) studies of orange juice using low-cost ceramic membrane prepared from locally available inorganic precursors. Characterization of the prepared membrane was carried out using scanning electron microscopy analysis, porosity determination and pure water permeation experiments. The average pore diameter, total porosity and hydraulic resistance of the membrane were evaluated as 0.285 µm, 23.6% and 9.26 × 1011 m2/m3, respectively. Dead-end MF experiments were performed for both centrifuged orange juice (CJ) and enzyme-treated centrifuged orange juice (ETCJ). It was observed that after MF, important properties like total soluble solid, pH, acidity and density of both CJ and ETCJ were almost unaffected. However, significant improvement in juice color, clarity and alcohol insoluble solid was observed. Permeate flux of 5.32 × 10−6 and 13.23 × 10−6 m3/m2.s were observed after 30 min of experimental run at 137.9 kPa trans -membrane pressure drop (ΔP ) for CJ and ETCJ, respectively. Various membrane pore blocking models were used to analyze the observed permeate flux decline. PRACTICAL APPLICATIONS The obtained microfiltration data for ceramic membrane-based clarification of orange juice could be useful to aid process design, development and operation studies for low-cost ceramic membrane technology-based juice processing systems. Pertinent flux decline behavior indicating the relevance of cake filtration model further indicates the applicability of membrane technology for juice processing applications with the fact that reversible membrane fouling is a proximate consequence of cake filtration and suitable cleaning procedures could enable long life span of the membrane. Enzyme treatment followed with membrane-based clarification of orange juice is found to be effective even from preservation and storage perspective. [ABSTRACT FROM AUTHOR]

In this article, we have reported the fabrication of stable macroporous ceramic support using low-cost inorganic raw materials by uniaxial dry compaction technique. The supports were prepared by mixing of inexpensive raw materials such as kaolin, quartz, calcium carbonate, sodium carbonate, boric acid, sodium metasilicate, and polyvinyl alcohol as a binder. The prepared green supports were sintered at different temperatures ranging between 900 and 1000°C. The raw materials and the sintered supports were characterized by thermogravimetric analysis, particle size distribution (PSD), X-ray diffraction, and scanning electron microscopy analysis. The influence of sintering temperature on the membrane structure, porosity, flexural strength, chemical stability, and the pure water permeability was also examined. It was observed that the average pore size and the flexural strength of the sintered supports increase with an increase in the sintering temperature. The porosity of the sintered supports was obtained in the ranges between 22 and 40%. The chemical stability of the sintered supports was found to be good. Based on the results obtained, the support sintered at 950°C (porosity of 30%, mechanical strength of 28 MPa, and average pore size of 3.45 µm) was considered as the optimum support for membrane applications. The ceramic support cost was estimated to be $67/m2 according to the raw material price. Henceforth, these low-cost membrane supports with better properties could be suggested for cheaper application in chemical and biochemical processes. [ABSTRACT FROM AUTHOR]

This article addresses the application the particle swarm optimization (PSO) algorithm as an optimization tool for retrieval of parameters in a combined mode 1-D transient conduction-radiation heat transfer problem. In the chosen problem, the participating medium is absorbing, emitting, and scattering. The boundaries are taken to be diffuse gray. In both direct and inverse methods, the energy equation is solved using the lattice Boltzmann method (LBM) and the finite volume method (FVM) is used to compute the radiative information. In the inverse method, the objective function is minimized using the PSO algorithm. The objective function considered in the inverse formulation is an error function evaluated with the exact and inverse temperature fields for the simultaneous retrieval of the extinction coefficient and the scattering albedo. The inverse analysis constituted the effect of measurement errors on solution efficacies. In addition, the effect of important PSO parameters such as swarm size, inertia factor and constriction factor on the parameter retrieval is considered. For the chosen problem, it is found that the PSO with 20 discrete particles and 50 iterations is adequate for accurate parameter retrieval. The PSO has been found to provide a better accuracy than the genetic algorithm. [ABSTRACT FROM AUTHOR]

Abstract: In this work, experimental investigations were carried out for the identification of optimal membrane morphological parameters (pore size distribution, average pore size and porosity) during microfiltration (MF) of mosambi juice using low cost ceramic membranes. Four different low cost ceramic membranes with different pore diameters (d m) and porosities (ɛ) were subjected to MF studies to evaluate the effect of d m and ɛ on permeation characteristics (permeate flux and juice quality) of centrifuged mosambi juice (CJ) and enzyme treated centrifuged mosambi juice (ETCJ). Subsequently, a convenient factor namely effective permeable area factor (ɛ m d m 2) was evaluated to provide greater insights in the fouling phenomena. Various physio-chemical properties such as colour, clarity, pH, citric acid content, density, total soluble solid (TSS) and alcohol insoluble solids (AIS) were measured for both feed and permeate juice samples to evaluate the effect of ɛ m d m 2 on juice quality. Typical permeate fluxes were observed to vary from 5.78×10−6 to 13.45×10−6 m3/m2 s for CJ and 14.07×10−6 to 60.64×10−6 m3/m2 s for ETCJ at 82.7kPa (ΔP) for different membranes whose ɛ m d m 2 varied from 0.249 to 0.783μm2. Among different membrane pore blocking models, flux decline by cake filtration was found to be the best fitted model. The cake filtration model constant (k c) was found to vary with ΔP and ɛ m d m 2 and was empirically correlated. Phenomenological models were proposed to illustrate the dependency of total hydraulic resistance of membrane on ɛ m d m 2, ΔP and time (t). Based on experimental as well as theoretical investigations, membranes with ɛ m d m 2 up to 0.443μm2 for CJ and 0.294μm2 for ETCJ and a ΔP of 82.7kPa were recommended for MF of mosambi juice. [Copyright &y& Elsevier]

This work addresses experimental and modeling studies on the treatment of oily wastewater emulsions using prepared lowcost ceramic membrane. Flat circular disk type membranes (52.5 mm diameter and 4.5 mm thickness) were used for microfiltration (MF) tests possessed a hydraulic pore diameter of 0.77 µm and total porosity of 42%. Synthetic oil-in-water emulsions constituting 50-150 mg/l oil concentrations were subjected to MF in batch mode of operation with varying transmembrane pressure differentials (δP) ranging from 41.37 to 206.8 kPa. Typica permeate flux of 15.05 x 10-6 m³/m²s and a rejection efficiency of 98.51% was observed fo mg/l feed oil concentration at δP of 206.8 kPa. Different pore blocking models such as complete pore blocking, standard pore blocking, intermediate pore blocking and cake filtration were used to gain insights into the nature of membrane fouling during permeation. The observed flux decline data trends infer that the decrease in permeate flux is due to intermediate pore blocking for the initial 1-10 min and later by cake filtration. Linear extrapolation of the data trends reveals that for feed oil concentrations above 250 mg/l, only cake filtration would be the flux decline mechanism. Finally, phenomenological models were proposed to illustrate the dependency of total hydraulic resistance of membrane on δP, initial oil concentration (c) and time (t). [ABSTRACT FROM AUTHOR]

This work addresses the applicability of different membrane pore blocking models for the prediction of flux decline mechanisms during dead end microfiltration (MF) of stable oil-in-water (o/w) emulsions using relatively low-cost ceramic membranes. Circular disk type membranes (52.5 mm diameter and 4.5 mm thickness) were prepared by the paste method using locally available low-cost inorganic precursors such as kaolin, quartz, calcium carbonate, sodium carbonate, boric acid, and sodium metasilicate. Characterization of the prepared membrane was done by SEM analysis, porosity determination, and pure water permeation through the membrane. Hydraulic pore diameter, hydraulic permeability, and hydraulic resistance of the membrane was evaluated as 0.7 µm, 1.94 × 10-6 m3/m2·s·kPa and 5.78 × 1011 m2/m3, respectively. The prepared membrane was used for the treatment of synthetic stable o/w emulsions of 40 and 50 mg/L crude oil concentration in batch mode with varying trans-membrane pressure differentials ranging from 41.37 to 165.47 kPa. The membrane exhibited 96.97% oil rejection efficiency and 21.07 × 10-6 m3/m2·s permeate flux after 30 min of experimental run at 165.47 kPa trans-membrane pressure for 50 mg/L oil concentration. Different pore blocking, models such as complete pore blocking, standard pore blocking, intermediate pore blocking and cake filtration were used to gain insights into the nature of membrane fouling during permeation. The observed trends for flux decline data convey that the decrease in permeate flux was initially due to intermediate pore blocking (during 1 to 10 minutes of experimental run) followed with cake filtration (during 10 to 30 minutes of experimental run). Based on retail prices of the inorganic precursors, the membrane cost was estimated to be 130 $/m2. Finally, preliminary process economic studies for a single stage membrane plant were performed for the application of the prepared membrane in industrial scale treatment of o/w emulsions. A process economics study inferred that the annualized cost of the membrane plant would be 0.098 $/m3 feed for treating 100 m3/day feed with oil concentration of 50 mg/L. [ABSTRACT FROM AUTHOR]

The lattice Boltzmann method (LBM) is applied to solve the energy equation of a transient conduction-radiation heat transfer problem in a 1-D concentric cylindrical participating medium. The finite-volume method (FVM) is used to obtain the radiative information. To study the effectiveness of the LBM-FVM combination to conduction-radiation problems in cylindrical media, the energy equation of the problem is also solved using the finite-difference method (FDM) in which the FVM is used to compute radiative information. The effects of different parameters, such as the conduction-radiation parameter, the scattering albedo, the extinction coefficient, and the radius ratio on temperature distributions in the medium are studied. Results of the present work are benchmarked against those available in the literature. LBM-FVM results are also compared with those obtained by the FDM-FVM combination. In all cases, excellent agreement has been obtained. [ABSTRACT FROM AUTHOR]