Process Safety and Environmental Protection, Vol.143, 76-90, 2020
Simultaneous removal of Fe(II) and Mn(II) from acid mine wastewater by electro-Fenton process
The treatment of acid mine wastewater containing Fe(II) and Mn(II) has been a hot topic in a long time. This paper studied the treatment of acid mine wastewater by the electro-Fenton process. First, the effect of key parameters including initial current intensity (50-300 mA), plate spacing (0.5-3.0 cm), and initial pH (3.0-5.0), aeration rate (0-200 mL/min) were studied. Based on these results, the performance of electroFenton process in actual wastewater and the stability of electro-Fenton system were investigated. Then the removal mechanism and mutual promotion effect were analyzed. The removal efficiency of Fe(II) and Mn(II) in wastewater could reach 99.2 % and 90.5 %, respectively, under the optimal conditions (current intensity 200 mA, initial pH 4.0, plate spacing 1.5 cm, aeration rate 100 mL/min). Electro-Fenton process has an important effect in actual wastewater treatment (removal efficiency of Fe(II) and Mn(II) reached 96.5 %, and 87.5 %, respectively), while the stability of this process was good. The optimal conditions were optimized through Box-Behnken design and response surface method (RSM). Removal efficiency of Fe(II) and Mn(II) could reach 99.6 % and 92.9 %, respectively, under optimized conditions (current intensity 210 mA, plate spacing 1.6 cm, initial pH 4.0, aeration rate 110.4 mL/min). In addition, the economic advantage of electro-Fenton process in acid mine wastewater treatment were evaluated. The result indicated that the cost of electro-Fenton process was only 0.56 $/m(3). (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords:Acid mine wastewater;Electro-Fenton;Removal mechanism;Response surface method;Economic advantage