Removal of arsenic from simulation wastewater using nano-iron/oyster shell composites.

In this paper, a nano-iron/oyster shell composite (NI/OS) was firstly prepared by an in-situ synthesis method to explore an efficient treatment technology for arsenic (As) contaminated wastewater. The micromorphologies and composition of the composite were characterized using field emission scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of the preparation parameters, as well as the treatment conditions, on the removal of As(Ⅲ) were also investigated. The characterization results showed that iron nanoparticles with a diameter of 60 nm were introduced into the composite by an in-situ reduction method. The physicochemical properties of the iron nanoparticles, such as diameter and aggregation, were influenced by the iron source more than the choice of reductant and temperature in the synthesis process, and these properties were closely related to the treatment performance of the composite. Under the suitable reaction conditions of a pH value of 6.8, a temperature of 20 °C, and an initial concentration of As(Ⅲ) of 1.8 mg/L, As(Ⅲ) was almost completely removed from the simulation wastewater.