PMC:4764609 / 18514-20409 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/4764609","sourcedb":"PMC","sourceid":"4764609","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4764609","text":"Adsorption kinetics\nThe kinetics of adsorption of copper at different contact times was found out using the pseudo-first order, pseudo-second order, and intra-particle diffusion models. The pseudo-first order equation is4 logqe-qt=logqe-K1/2.303twhere q e and q t are the amount of metal adsorbed at equilibrium and at time t; K 1 is the rate constant of pseudo-first order (min−1).5 The pseudo-second order equation ist/qt=1/K2qe2+1/qe(t)where K 2 (min−1) is the pseudo-second order rate constant.\nIntra-particle diffusion equation is6 qt=Kintt1/2+Cwhere K int is intra-particle diffusion rate constant (mg/g min1/2) and C is the boundary layer thickness.\nThe pseudo-first order, pseudo-second order and intra-particle diffusion kinetic plots are given in Fig. 2a–c respectively. In the pseudo-first order, the K 1 and q e values were 0.0582 (min−1) and 1.2103 (mg/g) respectively with a correlation coefficient (R 2) of 0.9586. In the pseudo-second order, the K 2 and q e values were 0.1104 (min−1) and 3.2362 (mg/g) respectively with a correlation coefficient (R 2) of 0.9989. The intra-particle diffusion, a plot of solute sorbed against square root of contact time, should normally yield a straight line passing through the origin but the line in the present case, did not pass through the origin and the values of K int and C were 0.1341 (mg/g min½) and 2.0427 (mg/g) respectively with a correlation coefficient (R 2) of 0.8942. From the experiments, q e obtained was 3.1308 mg/g which is suggestive that the adsorption of copper by DNES–CH composite could be by chemisorption, appropriately explained by the pseudo-second order model.\nFig. 2 a Pseudo-first order kinetics for adsorption of copper using DNES–CH composite. b Pseudo-second order kinetics for adsorption of copper using DNES–CH composite. c Intra-particle diffusion kinetics for adsorption of copper using DNES–CH composite","divisions":[{"label":"title","span":{"begin":0,"end":19}},{"label":"p","span":{"begin":20,"end":498}},{"label":"label","span":{"begin":220,"end":221}},{"label":"label","span":{"begin":382,"end":383}},{"label":"p","span":{"begin":499,"end":656}},{"label":"label","span":{"begin":535,"end":536}},{"label":"label","span":{"begin":1642,"end":1648}}],"tracks":[]}