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Response surface methodology is successfully utilized for the optimization of the composition of Polycaprolactone based nanocomposite membrane. The amount of nanoclay used as the additive and Polyethylene glycol as the pore former is optimized based on the membrane properties porosity and hydrophilicity. The quadratic equations are obtained using the central composite design and the ANOVA results are validated. The values for the coefficient of determination (R-squared), adjusted R-squared, adequate precision and coefficient of variance describe the significance of the model developed for the responses, porosity and contact angle. Eigen value analysis of the Hessian matrix for each response has been carried out and the nature of optimum is found maximum for porosity and minimum for contact angle. Residual plots have been analysed to validate the obtained models and the combined interaction of the variables was analysed using contour plots and surface plots. The independent variables and their levels have been determined using batch studies with one parameter optimization. Also, the optimized composition obtained using one parameter optimization and RSM analysis is compared and the composition optimized using RSM is found to be less with better membrane porosity and contact angle. [ABSTRACT FROM AUTHOR]

Activated carbon was prepared fromAreca triandrapalm shell (ATPS) by chemical activation with sulphuric acid, and its application for the adsorption of methylene blue dye from aqueous solution was investigated. FTIR spectral analysis and Boehm titrations were used to examine the oxygenated surface functional groups tailored to adsorb cationic toxins from solutions, point of zero charge estimated the surface charge for electronic affinity induced by chemical treatment. BET and SEM analyses revealed mesoporous adsorbent with homogenous pores and the BET surface area is 27.3 m2/g. The influence of process parameters, namely contact time, initial concentration, adsorbent dosage and pH was evaluated by batch adsorption studies. The equilibrium adsorption data were fitted with three isotherm models, among them Langmuir isotherm model best fitted and the maximum adsorption capacity of methylene blue was found to be 312.5 mg/g. The kinetic adsorption data best fitted with pseudo-second-order kinetics out of three kinetic models tested. The thermodynamic parameters, Gibb’s free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) ascertain that the adsorption is a spontaneous endothermic process with high affinity between surface and dye. The results of the present study suggest that the adsorbent prepared from ATPS is a potential adsorbent for the treatment of effluent containing cationic dyes. [ABSTRACT FROM AUTHOR]

Optimization studies on fermentative hydrogen production were investigated using a facultative bacteria namely, Enterobacter species (MTCC 7104). The present study emphasizes the application of mathematical tools such as response surface methodology (RSM) and artificial neural network (ANN) to predict the maximum yield of hydrogen from the optimized carbon and nitrogen source. The key components such as glucose, initial pH, xylose, tryptone, yeast extract, sucrose, and peptone were screened using the Plackett-Burman design. Furthermore, rotatable central composite design and analysis of variance were adopted to investigate the interactive effect of the significant variables (xylose concentration, initial pH, and peptone concentration). Maximum experimental hydrogen yield of 1.94 mol H2/mol xylose was achieved at the optimal points predicted by the RSM. Modeling ability of ANN and RSM has also been evaluated on predicting the maximum hydrogen yield with the estimated values of root mean square error (RMSE), multiple correlation coefficients (R2), and standard error of prediction (SEP). The estimated values of RMSE, R2, and SEP for ANN model and RSM model confirm that fitness and prediction accuracy of ANN model were higher when compared to RSM model. Energy conversion efficiency and energy recovery analysis were performed for hydrogen production process using xylose as the source material. [ABSTRACT FROM AUTHOR]

This work is the first, to the best of our knowledge, to use polycaprolactone (PCL)-based membrane for the treatment of dairy wastewater. PCL is a biodegradable polymer with high biocompatibility and good oil resistance. The chlorine tolerance analysis of PCL-based membranes exhibited a good tolerance against chlorine. The PCL/TiO 2 nanocomposite membrane with the addition of polyethylene glycol was prepared and tested for protein separation. The dependency of contact angle with time was analysed for the membrane, and the contact angle value reduced from 74.5 ± 2° to a steady value of 65 ± 2° in 120 s. The proteins were removed using a cross-flow filtration unit at an operating pressure of 0.4 MPa at room temperature with permeate flux of 10 L/m 2 h and a relative permeate flux of about 0.10. The removal of proteins was measured qualitatively using native polyacrylamide gel electrophoresis (PAGE) and quantitatively using Lowry's test. A percentage rejection of 97.6 was obtained and the native PAGE showed the complete removal of all the major proteins present in the milk sample.