In-Seob Kwak

Platinum recovery from ICP wastewater by a combined method of biosorption and incineration

A high performance biosorbent, polyethylenimine (PEI)-modified biomass, was prepared by attaching PEI onto the surface of inactive Escherichia coli biomass. Wastewater containing platinum was collected from an industrial laboratory for inductively coupled plasma (ICP) and used for the recovery study. The maximum platinum uptake of PEI-modified biomass was enhanced up to 108.8 mg/g compared to 21.4 mg/g of the raw biomass. Kinetic experiments revealed that sorption equilibrium could reach within 60 min for the PEI-modified biomass. The results of FTIR and XPS analysis of Pt-unloaded and Pt-loaded PEI-modified biomass indicated that electrostatic interaction was the main binding mechanism between the platinum ions and the binding sites on the surface of the biomass. Metallic form of platinum in ash was recovered by incineration with a recovery efficiency of over 98.7%. Furthermore, XPS, TEM and XRD results confirmed that the platinum recovered were both forms of Pt(0) and Pt(2+).

Preparation of PEI-coated bacterial biosorbent in water solution: Optimization of manufacturing conditions using response surface methodology

The aim of this study is to optimize preparation method of polyethyleneimine (PEI)-coated bacterial biosorbent in water as reaction media using fermentation waste biomass of Corynebacterium glutamicum as a raw material. The fermentation waste biomass of C. glutamicum and Reactive Red 4 were used as model raw bacterium and pollutant. Major factors affecting the performance of PEI-coated biosorbent were the amounts of polymer (PEI) and cross-linker glutaraldehyde (GA). These factors were optimized through response surface methodology (RSM) with two-level-two-factor (2(2)) full factorial central composite design. As a result, the optimum conditions were found to be 4.29 g of PEI and 0.15 mL of GA, with 10 g of the biomass, where the sorption capacity was enhanced 4.52-fold compared to that of the raw biomass. Therefore, this simple, cost-effective, and water-based method could be a useful modification tool for the development of a high performance biosorbent for removing anionic pollutants.