Answer to Question #169048 in Physical Chemistry for Robin

Question

Atrazine can be removed from water by adsorption to activated carbon. The Freundlich {q=KC^(1/n)} parameters for atrazine are K = 182 mg/g (L/mg)^1/n and 1/n = 0.18. What is the adsorbed concentration of the contaminant (units of mg chemical per gram of activated carbon) if you want the aqueous phase concentration at equilibrium to be 10 μg/L? Round off to nearest integer.

Answer 1

To investigate the adsorption mechanism on atrazine removal, the effect of solution pH and ionic strength was studied. A 2.0-mg PA6/PPy NFM was immersed into 2 mL of 10 mg/L atrazine aqueous solution in a 10-mL glass conical flask with cover for 12 h at 293 K.

The effect of pH value on the adsorption of atrazine using PA6/PPy NFM was tested by varying solution pH from 3 to 11. The pH of the solution was adjusted using 0.1 M HCl or 0.1 M NaOH. Meanwhile, to study the effect of ionic strength on the adsorption of atrazine, a series of experiments was carried out with the concentrations of NaCl changed from 2.5% to 10% and the pH of the initial solution remained at 7.

The adsorption capacities of PA6 NFM and PA6/PPy NFM were also tested for comparison purpose under the same experimental conditions. A 2.0-mg PA6/PPy NFM was added into 2 mL of atrazine solutions at two initial concentrations of 1 and 10 mg/L. The adsorption experiment was carried out at 293 K and continued for 12 h to reach adsorption equilibrium