Biosorption of nickel (II) ions from aqueous solutions by tapioca peel

Tapioca peel, waste from native tapioca starch industry in Thailand, was used for the biosorption of nickel from aqueous solution. The experimental parameter focuses on the influence of contact time, solution pH, initial concentration and temperature using batch experiments. The results indicated that the biosorption process was relatively fast, and equilibrium was reached after about 30 min of contact. At pH 5, the nickel removal reached a maximum value. The kinetics and equilibrium data was best-fitted pseudo second-order and Langmuir isotherm indication monolayer chemisorption with maximum capacity 20.37 mg/g. The biosorption process was endothermic and spontaneous in nature. Fourier transform infrared spectroscopy (FTIR) analysis revealed that hydroxyl and carboxyl groups of tapioca peel were mainly responsible for the biosorption of nickel. The regeneration experiments showed that the biosorption capacity of tapioca peel was a total slight decreased 8.8% for five cycles. Tapioca peel in this work has high biosorption capacity that can be used as alternative biosorbent for treatment to remove nickel from wastewater in an efficient and economical way.Key words: Biosorption, desorption, tapioca peel, regeneration, nickel removal