Comparative Analysis of Linear and Nonlinear Methods of Estimating the Pseudo-Second-Order Kinetic Parameters for Sorption of Malachite Green onto Pretreated Rice Husk

2011 ◽  
Vol 15 (4) ◽  
pp. 181-188 ◽  
Author(s):  
Shamik Chowdhury ◽  
Papita Das Saha
2011 ◽  
Vol 8 (s1) ◽  
pp. S363-S371 ◽  
Author(s):  
C. Theivarasu ◽  
S. Mylsamy

The removal of malachite green (MG) by cocoa (Theobroma cacao) shell activated carbon (CSAC) was investigated in present study. Adsorption studies were performed by batch experiments as a function of process parameters such as initial pH, contact time, initial concentration and adsorbent dose. A comparison of kinetic models applied to the adsorption of MG on CSAC was evaluated for the pseudo-first order and pseudo-second order kinetic models. Results showed that the pseudo-second order kinetic model was found to correlate the experimental data well. The experimental equilibrium adsorption data was represented with Langmuir, Freundlich, Tempkin, Dubinin-Radushkevich and Flory-Huggins isotherms. The experimental data obtained in the present study indicated that activated carbon developed from cocoa shell can be attractive options for dye removal from waste water.


2012 ◽  
Vol 560-561 ◽  
pp. 1174-1177 ◽  
Author(s):  
Dimitar Petrov Georgiev ◽  
Bogdan Iliev Bogdanov ◽  
Yancho Hristov ◽  
Irena Markovska

In this study, the sorption of Cu(II) ions in aqueous solutions of Zeolite NaA by performing batch kinetic sorption experiments. The equilibrium kinetic data were analyzed using the pseudo-second-order kinetic model. A comparison was made of the linear least-squares method and nonlinear method of the widely used pseudo-second-order kinetic model for the sorption of Cu(II) ions of Zeolite . Four pseudo-second-order kinetic linear equations are discussed. Kinetic parameters obtained from the four kinetic linear equations using the linear method differed but they were the same when using the non-linear method. Kinetic parameters obtained from four kinetic linear equations using the linear method differed. Equation type 1 pseudo-second-order kinetic model very well represented the kinetic of the adsorption Cu(II) ions by Zeolite NaA. Equation type 4 exhibited the worst fit. Present investigation showed that the non-linear method may be a better way to determine the kinetic parameters.


2014 ◽  
Vol 16 (4) ◽  
pp. 676-689 ◽  

<div> <p>In the present study, batch adsorption studies were performed for the removal of malachite green and acid blue 161 dyes from aqueous solutions by varying parameters such as contact time, waste marble dust amount, initial dye concentration and temperature. The equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin adsorption isotherm models. The Langmuir and Freundlich adsorption models agree well with experimental data. The pseudo-second order, intraparticle intraparticle diffusion and Elovich kinetic models were applied to the experimental data in order to describe the removal mechanism of dye ions by waste marble dust. The pseudo-second order kinetic was the best fit kinetic model for the experimental data. Thermodynamics parameters such as Δ<em>G</em>, Δ<em>H</em> and Δ<em>S </em>were also calculated for the adsorption processes. The experimental data were used to construct an artificial neural network (ANN) model to predict removal of malachite green and acid blue 161 dyes by waste marble dust. A three-layer ANN, an input layer with four neurons, a hidden layer with 12 neurons, and an output layer with one neuron is constructed. Different training algorithms were tested on the model to obtain the proper weights and bias values for ANN model. The results show that waste marble dust is an efficient sorbent for malachite green dye and ANN network, which is easy to implement and is able to model the batch experimental system.</p> </div> <p>&nbsp;</p>


2021 ◽  
Author(s):  
Vani Gandham ◽  
UMA Addepally ◽  
Bala Narsaiah T

Abstract Malachite Green (MG), a cationic synthetic dye is considered hazardous when discharged into the water bodies without any adequate treatment. It can affect the multiple segments of the environment leading to irreversible persistent changes. So, there is a need for remediation with cost-effective method to remove dyes from effluents. Adsorption is one such technique to remove dyes from wastewater and is effective and economical. The present study describes the removal of MG cationic dye from wastewater using eco-friendly and biodegradable lignin extracted from hydrothermally treated rice straw by adsorption process. Functional group analysis and morphological characterisation was done to the extracted lignin after quantification. The maximum percent removal of MG 92 ± 0.2 % was observed from a series of batch experiments at optimum process parameters of: contact time 80 min, initial dye concentration 50 ppm, lignin dosage 0.25g, pH 7, temperature 300c and with 100 rpm agitation speed. The adsorption kinetics and isotherms were determined for the experimental data using four kinetic models (pseudo-first-order, second order, pseudo-second-order and intra-particle diffusion model) and two isotherm models (Langmuir and Freundlich). The results suggested that the kinetics data fit to the pseudo-second-order kinetic model with the maximum adsorption capacity 36.7 mg/g and the two isotherm models were applicable for the adsorption of MG onto the lignin. Additionally, the thermodynamic parameters ΔSo, ΔHo and ΔGo were evaluated. Therefore, lignin which is an environmental friendly and low cost carbon material that can be used as an adsorbent for dye removal.


2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Xia Luo ◽  
Sabrina Jedlicka ◽  
Kristen Jellison

ABSTRACT Cryptosporidium parvum oocysts are able to infect a wide range of mammals, including humans, via fecal-oral transmission. The remobilization of biofilm-associated C. parvum oocysts back into the water column by biofilm sloughing or bulk erosion poses a threat to public health and may be responsible for waterborne outbreaks; thus, the investigation of C. parvum attachment mechanisms to biofilms, particularly the physical and chemical factors controlling oocyst attachment to biofilms, is essential to predict the behavior of oocysts in the environment. In our study, biofilms were grown in rotating annular bioreactors using prefiltered stream water (0.2-μm retention) and rock biofilms (6-μm retention) until the mean biofilm thickness reached steady state. Oocyst deposition followed a calcium-mediated pseudo-second-order kinetic model. Kinetic parameters (i.e., initial oocyst deposition rate constant and total number of oocysts adhered to biofilms at equilibrium) from the model were then used to evaluate the impact of water conductivity on the attachment of oocysts to biofilms. Oocyst deposition was independent of solution ionic strength; instead, the presence of calcium enhanced oocyst attachment, as demonstrated by deposition tests. Calcium was identified as the predominant factor that bridges the carboxylic functional groups on biofilm and oocyst surfaces to cause attachment. The pseudo-second-order kinetic profile fit all experimental conditions, regardless of water chemistry and/or lighting conditions. IMPORTANCE The cation bridging model in our study provides new insights into the impact of calcium on the attachment of C. parvum oocysts to environmental biofilms. The kinetic parameters derived from the model could be further analyzed to elucidate the behavior of oocysts in commonly encountered complex aquatic systems, which will enable future innovations in parasite detection and treatment technologies to protect public health.


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