Sodium alginate nanocomposite based efficient system for the removal of organic and inorganic pollutants from wastewater

Abstract

An effective and selective catalytic system based on cerium oxide-stannous oxide (CeO2-SnO) wrapped Na-alginate hydrogel was developed for the selective reduction of potassium ferricyanide (K3[Fe(CN)6]). Na-alginate hydrogel was used as a reacting container for CeO2-SnO nanoparticles. Na-alginate wrapped CeO2-SnO (Alg/CeO2-SnO) was applied as a catalyst and examined toward the reduction of several hazardous pollutants, such as nitrophenols, dyes and K3[Fe(CN)6]. Alg/CeO2-SnO nanocatalyst was mostly selective toward K3[Fe(CN)6] since it was more effective and economical for reduction of K3[Fe(CN)6]. Further different parameters like catalyst amount, reducing agent amount, K3[Fe(CN)6] concentration and recyclability were optimized. The increase in both nanocatalyst amount and NaBH4 concentration resulted in increasing the rate of the catalytic reduction of K3[Fe(CN)6]. Alg/CeO2-SnO nanocatalyst reduced K3[Fe(CN)6] in 4.0 min with a reaction rate constant of 0.9114 min−1. The nanocatalyst can be easily recovered by pulling the hydrogel from the reaction medium up to four cycles. Alg/CeO2-SnO nanocatalyst was also examined in real samples like irrigation water, sea water, well water, university water, which was effective for K3[Fe(CN)6] reduction by 95.16%–96.54%. This novel approach provides a new catalyst for efficient removal of K3[Fe(CN)6] from real samples and can be a time and cost alternative tool for environmental safety.