Cu2+ removal in simulated and actual EDTA–Cu wastewater EDTA–Cu solution was prepared with Cu2+ and EDTA according to a molar ratio of 1:1. CuSO45H2O (3.932 g) and disodium EDTA
(5.862 g) were weighed accurately and dissolved in distilled water, then settled to 1000 mL (the concentration of Cu2+ was 1000 mg/L). DTC–TBA (30 g) was dissolved in distilled water and settled to 1000 mL (the concentration of DTC–TBA was 30 g/L), while 1‰ PAM solution was prepared with 1.0 g PAM and 1 L distilled water.
Simulated EDTA–Cu wastewater (100 mL) was diluted to 100 mg Cu2+/L and added to a conical flask. After pH of the solution was adjusted to 1–9 with 0.1 mol/L H2SO4 and 0.1 mol/L NaOH, DTC–TBA was added to each sample quantitatively. Followed by oscillation for 3 min at 283–303 K with rotational velocity of 120 rpm in a thermostat box, PAM solution was dosed to the samples. With continued oscillation for 2 min, sediment occurred if left to stand. The concentrations of Cu2+ in supernatants were determined.