Sorption of cadmium and nickel from solution by peat and modified peat

The performance of peat and modified peat in the remediation of wastewater containing cadmium (Cd) and nickel (Ni) was investigated in both batch and continuous process. Peat is an attractive natural sorbent because it is widespread and inexpensive. The sorption capacity can be determined using Langmuir and Freundlich isotherms. The batch sorption results showed that sulfuric acid treatment (STP) enhances the sorption capacity of the peat. Temperature, concentration of metals and time influences the sorption process. Breakthrough curves for cadmium and nickel were evaluated for several column characteristics: the height of the exchange zone, time taken by the exchange zone to travel its own height and rate of movement of the exchange zone. The column showed a better performance at lower concentration when compared to higher concentrations of cadmium and nickel. From the infrared (IR) measurements the difference in the antisymmetrical and symmetrical stretching of carboxylic group of peat confirms an unidentate complex with Ni and Cd