Recovery and application of heavy metals from pickling waste liquor (PWL) and electroplating wastewater (EPW) by the combination process of ferrite nanoparticles

Abstract

Heavy metal contamination in wastewater poses a severe threat to the environment and public health. Magnetic iron-based materials are effective for heavy metal wastewater treatment, resources conservation, and recycling of metal ions. In the present work, two kinds of heavy metal wastewater were used to fabricate magnetically separable MnFe₂O₄ and CuFe₂O₄ as catalysts. The obtained catalysts were characterized by scanning electron microscopy, X-ray diffractometry, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. Results showed that MnFe₂O₄ and CuFe₂O₄ MNPs could effectively activate peroxymonosulfate (PMS) to generate powerful sulfate radicals () for Rhodamine B (RhB) removal. More than 99% of RhB (10 mg/L) was degraded within 20 min using 0.4 g/L MnFe₂O₄ MNPs and 0.2 g/L PMS. The most effective pH for RhB degradation by PMS/WB-MnFe₂O₄ was 3. And under the condition of catalysts loading (0.40 g/L), dye concentration (10 mg/L), PMS = 0.2 g/L and T = 25°C, the stability and reusability of MnFe₂O₄ and CuFe₂O₄ MNPs was investigated. Recycled WB-MnFe₂O₄ MNPs showed strong activity in RhB degradation and its activity remained almost unchanged in eight cycles, while the activity of WB-CuFe₂O₄ MNPs dropped down after three cycles.

Keywords:

• Heavy metal wastewater
• Ferrite
• Rhodamine B
• Peroxymonosulfate activation
• Sulfate radical

Acknowledgments

This study was supported by Program for Innovative Research Team in University (No. IRT13078), as well as been supported by National Nature Science Foundation of China Nos. 50704023, 50974086 and 51274138. This study was also funded by China Scholarship Council.

Notes

Presented at the 8th International Conference on Challenges in Environmental Science & Engineering (CESE-2015) 28 September–2 October 2015, Sydney, Australia