Synergetic Effects of Zero-valent Iron and Morganella morganii on the Removal of Cr(VI) from Wastewater

Abstract

Zero-valent iron permeable reactive barrier (ZVI-PRB) has attracted great attention for its high efficiency and low cost in the in-site remediation process. However, passivating oxide layers are usually yielded and covered on the surface of ZVI, which shorten the service life of PRB. In this study, Morganella morganii subsp was used to hydrolyse the passivating oxide layers on ZVI. The hydrolysing condition was optimized. The highest Cr(VI) removal efficiency was achieved with glucose of 4 g/L, yeast powder of 6 g/L and pH = 7. With Morganella morganii subsp, the maximum removal quality of ZVI was increased from 19.96 mg/g to 24.35 mg/g, indicating Morganella morganii subsp could improve the reduction ability of ZVI. SEM-EDS analysis also showed that M. morganii subsp could promote the surface corrosion of ZVI and adsorb Cr simultaneously.

Keywords

• environment