Ramgopal Uppaluri

Treatment of Oily Waste Water Using Low-Cost Ceramic Membrane: Flux Decline Mechanism and Economic Feasibility

Abstract 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

An Inverse Analysis for Parameter Estimation Applied to a Non-Fourier Conduction–Radiation Problem

/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

Manufacture of Nickel-Ceramic Composite Membranes in Agitated Electroless Plating Baths

/m3 feed for treating 100 m3/day feed with oil concentration of 50 mg/L.

Simultaneous Retrieval of Parameters in a Transient Conduction-Radiation Problem Using a Differential Evolution Algorithm

Retrieval of parameters in a non-Fourier conduction and radiation heat transfer problem is reported. The direct problem is formulated using the lattice Boltzmann method (LBM) and the finite-volume method (FVM). The divergence of radiative heat flux is computed using the FVM, and the LBM formulation is employed to obtain the temperature field. In the inverse method, this temperature field is taken as exact. Simultaneous estimation of parameters, namely, the extinction coefficient and the conduction–radiation parameter, is done by minimizing the objective function. The genetic algorithm (GA) is used for this purpose. The accuracies of the estimated parameters are studied for the effects of measurement errors and genetic parameters such as the crossover and mutation probabilities, the population size, and the number of generations. The LBM-FVM in combination with GA has been found to provide a correct estimate of parameters.

Effect of surfactants on performance of electroless plating baths for nickel–ceramic composite membrane fabrication

Nickel hydrazine electroless plating baths with membrane stirring as a mass transfer enhancement is considered to evaluate the membrane morphological dependence on metal solution concentration, loading ratio (membrane area per unit volume of plating solution), and stirrer speed. Inexpensive sintered ceramic supports with an average pore size of 275 nm were used for all experimental investigations. Other parametric investigations include conversion and plating efficiency. It was observed that the loading ratio significantly influenced metal film thickness but not the nominal pore size of the membranes. On the other hand, effect of stirrer speed is significant for solutions with 0.04 mol/L metal solution concentrations, moderate for solutions with 0.08 mol/L solution concentration, and insignificant for 0.16 mol/L concentration. Based on several experimental investigations, it is inferred that the optimal choice of the agitated plating process are 0.08 mol/L initial nickel solution concentration, 393 cm2/L of loading ratio, and 100 rpm stirrer speed.

Influence of Sintering Temperature on the Properties of Porous Ceramic Support Prepared by Uniaxial Dry Compaction Method Using Low-Cost Raw Materials for Membrane Applications

This article deals with the application of the differential evolution (DE) algorithm for the inverse analysis of a transient conduction-radiation heat transfer problem. Thermophysical properties and/or optical properties of the medium are simultaneously retrieved with a known temperature field. The conducting-radiating planar enclosed medium bounded by diffuse-gray boundaries is absorbing, emitting, and scattering. In both the direct and inverse methods, the energy equations are 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 DE algorithm. Any two sets of parameters, viz., the extinction coefficient, the scattering albedo, emissivity and conduction-radiation parameter, are simultaneously retrieved. The effects of key DE algorithm parameters, such as the weighting factor and the crossover constant on the quality of solutions, are studied. Measurement errors are accounted. The accuracy of the DE algorithm is compared with the genetic algorithm. The DE algorithm is significantly faster, and it yields the global optimum for a wide range of parameters.

Pd(II) adsorption characteristics of glutaraldehyde cross-linked chitosan copolymer resin.

Abstract Nickel–ceramic microfiltration membranes were prepared by electroless deposition of nickel on the activated ceramic membrane substrates having a nominal pore size of 275 nm. Two different surfactants, namely sodium dodecyl sulphate (SDS) and cetyltrimethyl ammonium bromide (CTAB), were studied for their ability to alter the performance characteristics of plating baths as well as composite membranes. Parameters evaluated include the bath conversion, plating efficiency, metal film thickness, average pore size of the composite membranes and per cent pore densification. The overall plating rate was found to increase up to 32% with the addition of SDS and 45% with the addition of CTAB. Addition of surfactants not only resulted in increased film thickness (4–5 μm) but also accounted for considerable reduction in average pore size of the composite membrane. CTAB was found to be more effective and efficient than SDS for nickel membrane fabrication.

Equilibrium and Kinetic Studies of Ni (II) Adsorption using Pineapple and Bamboo Stem Based Adsorbents

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

Effect of Ultrasound on the Performance of Nickel Hydrazine Electroless Plating Baths

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.

Simultaneous Reconstruction of Thermal Field and Retrieval of Parameters in a Cylindrical Enclosure

Deliberating upon the role of solution chemistry in influencing the Pd(II) adsorption and desorption characteristics using chitosan based resins, this work addresses the competence of glutaraldehyde cross-linked chitosan (GCC) co-polymer resin for the removal and recovery of Pd(II) from synthetic electroless plating solutions. GCC copolymer adsorbent was prepared by grafting of fixed weight ratio (1/17) of medium molecular weight chitosan and glutaraldehyde (25% in H2O). Within the adsorption parametric range of 2-10pH, 60-300min contact time, 10-50mg adsorbent dosage and 50-500mg/L initial Pd(II) concentration, the solution chemistry associated to synthetic ELP solution has been evaluated to strongly reduce the adsorption capacity of the GCC resin. Batch equilibrium adsorption studies inferred upon the fitness of Langmuir isotherm with a monolayer adsorption capacity of 166.67mg/g. Adsorption kinetics and thermodynamic parametric evaluations affirmed pseudo-second-order kinetics and spontaneous exothermic Pd(II) adsorption on the resin. Further, speciation analysis provided valuable insights by indicating greater favourability of Pd(NH3)42+ species (at pH=8) than PdEDTA-2 (at lower pH) to foster chemisorption with the GCC resin. In summary, the observations affirmed that solution chemistry needs to be addressed in laboratory investigations to further industrial application and competitiveness of alternate resins.