Application of response surface methodology (RSM) for optimization of color removal from POME by granular activated carbon

Abstract

Color is one of the major remaining contaminants in the palm oil mill effluent (POME) following the conventional treatment of POME. The removal of color from POME using adsorption on activated carbon was investigated. The adsorption experimental design was performed using the standard response surface method (RSM) design that is central composite design to determine the optimum process variables for color removal by using the Design-Expert software (version 7.0. Stat-Ease, trial version). Besides obtaining optimum values, RSM also has the advantage of studying the interaction between various experimental parameters compared to one-factor-at-a-time. The equilibrium experimental data were analyzed by Langmuir and Freundlich isotherms. The statistical analysis showed that the quadratic model as well as the model terms was significant. The model had very low probability value (0.0003). The R 2 for the model was 0.9184 and the adjusted R 2 was 0.8380. The validation of the model showed experimental value and predicted value of 0.124 and 0.106, respectively. The optimum conditions suggested by the model for the process variable were 87.9 min, 4.05 and 7.86 g, for time, pH and granular activated carbon dose, respectively. The maximum removal obtained at these conditions was 89.95 %. The adsorption isotherm data were fitted well to the Langmuir isotherm compared to Freundlich isotherm with R 2 value of 0.850 for the former and 0.273 for the later.

Application of response surface methodology for optimization of biosorption of fluoride from groundwater using Shorea robusta flower petal

“…This design can easily be constructed by augmenting the fractional factorial design that was used for estimating the first-order model (Khuri 1996;Myers et al 2005). The advantages of CCD lie in its use in sequential experimentation (Myers et al 2005;Kumar et al 2006;Garg et al 2008;Bhatti et al 2011;Alkhatib et al 2015;Rehman et al 2015). In the present study, the experimental design for calcium impregnation was done using the response surface methodology (RSM).…”

“…where a o was the constant coefficient, a i was the linear coefficient, a ii was the quadratic coefficients, a ij was the interaction coefficients (Ozer et al 2009;Alkhatib et al 2015). The validity of the proposed polynomial equation was assessed by the values of R 2 , R 2 Adj and R 2 Pred .…”

“…Fluoride solutions of desired initial concentration were prepared by diluting stock solution using requisite amount of water. Several parameters such as initial concentration of fluoride, adsorbent dose, pH, particle size and temperature generally affect the kinetics of adsorption process (Alkhatib et al 2015;Chakrapani et al 2010;Rehman et al 2015) and the success of adsorption process depends on the proper selection of key parameters and their ranges. In the present case, since fluoride was the most electronegative element in the periodic table, its removal through adsorption greatly depends on electrostatic interaction between sorbent and sorbate.…”

“…This is possible by designing experiments statistically using statistical techniques such as response surface methodology (RSM) (Bhaumik et al 2013). Besides getting optimum conditions, RSM has the advantage of studying the interaction between various input parameters at a time compared to one-factor-at-a-time (OFAT) analysis (Alkhatib et al 2015). Such method involves (1) designing experiments in which the process parameters are varied statistically according to a set of experimental trials and determination of the output parameters; (2) analyzing the data and predicting empirical model using analysis of variance (ANOVA) and (3) numerical optimization (Yadav et al 2013).…”

Adsorption kinetic studies for removal of methylene blue using activated carbon prepared from sugar beet pulp

“…Among the numerous techniques, adsorption is the procedure of choice and gives the best results as it can be used to remove different types of dyes, simultaneously. Currently, adsorption by activated carbon (AC) has been considered to be the most widely used and effective physical method (Alkhatib et al 2015;Kaur et al 2015;Thitame and Shukla 2016).…”