Biosorption of Cu2+ onto Biyological Waste Nitrification Organisms

The biosorption of Cu2+ ions from aqueous solutions onto the dry waste nitrification organisms (DWNO) which were enriched in the laboratory was investigated in batch experimental system with respect to the temperature, initial Cu2+ concentrations, pH, and biosorbent doses. Considering the R2 value, qexp and qcal, the adsorption equilibrium was well described by the Langmuir isotherm model which is suggesting that the Cu2+ ions were adsorbed onto the DWNO in a monolayer. The value of qe increased with increasing the temperature while also increases the release of organic matter and NH4-N from the DWNO. The highest sorption of Cu2+ onto DWNO was determined at the initial pH value and temperature of 5.0 and 55°C, respectively. The results confirming that the biosorption reaction of Cu2+ on the DWNO was thought to be endothermic. A comparison of the kinetic models such as pseudo first and second-order kinetics, intraparticle diffusion, and Elovich on the sorption rate demonstrated that the system was best described by the pseudo second-order kinetic model. The value of ΔG° was decreasing with increasing temperature. It indicates that the adsorption process leads to an increase in Gibbs energy. The negative ΔG° value means the Cu2+sorption onto the DWNO is feasible.