Copper release kinetics from a long-term contaminated acid soil using a stirred flow chamber: Effect of ionic strength and pH

► Cu release was affected by both pH and the ionic strength. ► For pH below 4.5, the effect of pH was greater than ionic strength effect. ► For pH above 4.5, the effect of pH was less than ionic strength effect. ► Cu release was higher in the presence of Ca than in the presence of Na for the same ionic strength.