1. A novel method based on membrane distillation for treating acid mine drainage: Recovery of water and utilization of iron
- Author
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Xuwen He, Jianbing Wang, Yuxiang Wang, Zhongyi Li, Huijiao Wang, and Chunrong Wang
- Subjects
Environmental Engineering ,Iron ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,Sodium oxalate ,Membrane distillation ,01 natural sciences ,Mining ,Water Purification ,Catalysis ,law.invention ,chemistry.chemical_compound ,law ,Environmental Chemistry ,Distillation ,0105 earth and related environmental sciences ,Aqueous solution ,Chemistry ,Membrane fouling ,Public Health, Environmental and Occupational Health ,Water ,Membranes, Artificial ,General Medicine ,General Chemistry ,Acid mine drainage ,Pollution ,020801 environmental engineering ,Chemical engineering ,Photocatalysis ,Water Pollutants, Chemical - Abstract
Rapid and highly efficient treatment of acid mine drainage (AMD) is still challenging due to the low pH and high metal concentrations in it. This research focuses on a novel treatment method of AMD using direct contact membrane distillation (DCMD) and photocatalysis to recover water and utilize iron. In the DCMD process without pretreatment, the flux decreased by 93.38%. If pretreated by adding sodium oxalate, scale formation potential was effectively mitigated due to the removal of calcium and complexing of iron. For the treatment of the pretreated AMD (PAMD), 60% of water was recovered in the DCMD process with the flux decrease of 22%. The concentrate obtained from the DCMD process demonstrated high photocatalytic activity in the methylene blue (MB) degradation in an aqueous solution. In addition, the Fe (III)-oxalate complexes in the concentrate were reduced to insoluble Fe (II)-oxalate with visible light irradiation, which could be separated by sedimentation and used as a Fenton catalyst. Hence, this novel method exhibits great advantages on effectively inhibiting DCMD membrane fouling during AMD treatment, producing high-quality distillate with low conductivity, and realizing near zero-discharge of AMD.
- Published
- 2021