SYNTHESIS of MATERIALS PRODUCED from SPENT BATTERIES with ENVIRONMENTAL APPLICATION

Abstract

In this work, alkaline and nickel-metal hydride spent batteries were used as precursors of metals for the synthesis of polymetallic materials. These materials were synthesized via chemical reduction. Materials produced from nickel-metal hydride spent batteries (PM-NiMH) have a nanometric size, whereas the alkaline spent batteries (PM-Alk) have a micrometric size. PM-NiMH consists mainly of Ni, Co, and Cu and the PM-Alk consists mainly of Mn and Zn. The surface areas of PM-NiMH and PM-Alk were 82 m2 g-1 and 109 m2 g-1, respectively. The synthesized materials were applied in the removal of reactive blue dye 4 (RB4). Parameters such as initial pH of the system, dose of the materials, and initial concentration of the dye were optimized. For both materials, the removal capacity of RB4 was constant over a wide pH range of (4-10). The removal capacity increases with the decrease of the materials dose and increase of the dye concentration until saturation of the active sites. The RB4 removal by PM-NiMH occurs by adsorption and degradation processes, whereas PM-Alk occurs only by adsorptive processes. The RB4 removal process follows the Langmuir adsorption isotherm model with maximum removal capacities of 331 and 127 mg g-1 for PM-NiMH and PM-Alk, respectively.