Substrate Langmuir Parameters Freundlich Parameters qmax [mg/g] a R2 n KF R2 Cd2+ ZCR40 95.238 0.0004 0.997 - - 0.285       Cu2+       ZCR40 107.527 0.0003 0.917 - - 0.801 Cd2+(Cd2++Cu2+) ZCR40 36.764 0.016 0.920 - - 0.657 Cu2+(Cd2++Cu2+) ZCR40 53.763 0.001 0.993 - - 0.660 Cd2+(Cd2++Cu2++Ni2+) ZCR40 18.657 0.04 0.978 - - 0.652 Cu2+(Cd2++Cu2++Ni2+) ZCR40 13.774 0.001 0.970 - - 0.896 Ni2+(Cd2++Cu2++Ni2+) ZCR40 26.525 0.066 0.999 - - 0.665

Table 7: Adsorption isotherm parameters.