A stretchable gel-type floating material boosts photo-Fenton-adsorption for efficient purification of mineral processing wastewater

Abstract

Organic floatation reagents and heavy metals are the main pollutants produced from mineral processing industries. Traditional powder material is facing the challenges of difficult solid–liquid separation and fast dissolution during the wastewater treatment. In this paper, a stretchable halloysite based gel-type floating material (GF-HNTs@Mo/Fe) was synthesized to trigger photo-Fenton and adsorption reaction for the purification of the beneficiation wastewater. GF-HNTs@Mo/Fe exhibits good hydrophilicity which is very beneficial to suspend in water to absorb sun light and contact with pollutants under the force of hydrogen bond. Compared to single HNTs@MoS2/FeOOH powder material, GF-HNTs@Mo/Fe can be fabricated to any size and reserve most performance. Under optimized conditions, GF-HNTs@Mo/Fe can continuously remove aniline aerofloat (AAF), Cd2+ and COD both from simulated wastewater and actual lead zinc copper ore beneficiation wastewater over ultra-long time of 288 h, and still remain over 50 % treatment ability. Especially, after 13d treatment of actual beneficiation wastewater, 97.12 % of Cd2+, 85.46 % of AAF, 53.28 % of COD and 46.67 % of TOC still could be eliminated by GF-HNTs@Mo/Fe. Owing to the robust mechanical strength of GF-HNTs@Mo/Fe, it can be easily recovered for reuse and avoid secondary pollution. This GF-HNTs@Mo/Fe floating photo-Fenton-adsorption system not only solves solid–liquid separation issue in powder system, but decreases the drawback of performance loss when powder material was fabricated to bulk material.