Insights to enhanced coagulation based on the control of metal forms for treating acid mine drainage: Performance and
Kun Wu1, Yanjun Jia2, Dandan Song2
1School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No.13, Yanta Road, Beilin District, Xi'an 710055, Shaanxi, China; Key Lab of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, Shaanxi, China.
Abstract:
This study presents an enhanced oxidation-chelation-coagulation process for efficient acid mine drainage (AMD) treatment, addressing the limitations of conventional methods in terms of efficiency, cost, and environmental risks. Through systematic optimization, it was demonstrated that combined NaClO/KMnO₄ oxidation (3:1 molar ratio) at pH 8 effectively transformed Fe2 +/Mn2+ ions into insoluble Fe/Mn (hydr)oxides, while 0.40 g/L carboxymethyl cellulose (CMC) enabled effective chelation and removal of Pb/Ni. The process achieved exceptional removal efficiencies, reducing Fe from 2000 to 2.85 mg/L while maintaining Mn, Pb, and Ni below or close to China's discharge limits (2.0, 0.5, and 0.5 mg/L respectively). Surface characterization (XRD, XPS, FTIR) results revealed the flocs' composition (Fe(OH)₃/MnO₂) and identified functional groups (-COOH/-OH) onto CMC as crucial for metal chelation. Notably, 36.7-57.7 % of removed metals were stabilized in environmentally inert residual forms within the sludge, minimizing leaching potential. The synergistic combination of oxidation, chelation and coagulation mechanisms provides distinct advantages over conventional approaches, including: (1) superior simultaneous removal of multiple metals (Fe, Mn, Pb, Ni); (2) reduced chemical consumption through optimized reagent combinations; and (3) effective mitigation of secondary pollution risks via metal stabilization. These results provide a robust technical foundation for sustainable AMD remediation, offering significant improvements in treatment performance, cost-effectiveness, and environmental safety. The findings highlight the potential of hybrid chemical processes for complex wastewater treatment and provide valuable insights for practical implementation in mining-affected regions.
More Related Videos
11:14Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
Published on: February 21, 2017
13:11Using Flexible Gold-Titanium Reaction Cells to Simulate Pressure-Dependent Microbial Activity in the Context of Subsurface Biomining
Published on: October 5, 2019
Related Concept Videos
Coagulation
Extraction: Advanced Methods
Microbes and Other Elemental Cycles
Microbial Leaching
Acid Mine Drainage
Microbial Corrosion
