Study on the optimization of adsorption of Cu2+ by chaff using quadratic orthogonal rotation combination design

The effects of conditions including chaff dosage( X₁),p H value( X₂),adsorption time( X₃) and the initial concentration of Cu²⁺( X₄) on the adsorption properties of Cu²⁺were studied by single factor experiments.On the basis of single factor experiments,four main experimental conditions for the adsorption of Cu²⁺were optimized using quadratic orthogonal rotation combination design.A quadratic orthogonal regression model was established.According to the modal,the highest theoretical adsorption efficiency was obtained( 94.02%) under the conditions as follows: the initial concentration of Cu²⁺+5.04 mg·L⁽- 1),chaff dosage 3.84 g·L^-1,p H value 5.48 and reaction time42.85 min.Through repeatedly experimental test under this condition,the average adsorption rate reached 93.28%,which proved that the test was reliable.