Treatment of Metal Cutting Wastewaters in Bipolar Trickle Tower Reactor by Electrocoagulation and Electrochemical-Fenton methods: Reduction of Organic Matter, Boron, Heavy Metals, and Toxicity with Sludge Characterization

Gedik T., Ozmen F. K., Karel F. B., KOPARAL A. S.

WATER AIR AND SOIL POLLUTION, vol.232, no.12, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 232 Issue: 12
  • Publication Date: 2021
  • Doi Number: 10.1007/s11270-021-05423-6
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, ABI/INFORM, Agricultural & Environmental Science Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, Compendex, EMBASE, Environment Index, Geobase, Greenfile, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Electrocoagulation, Electrochemical-Fenton, Organic matter, RSM, Boron, Toxicity, TEXTILE WASTE-WATER, ELECTRO-FENTON, OXIDATION, REMOVAL, DEGRADATION, COAGULATION, EMULSIONS, COLOR, COD
  • Anadolu University Affiliated: Yes


The metal cutting wastewater was treated with electrocoagulation (EC) and electrochemical-Fenton (EF) method in a bipolar trickle tower reactor. In EC treatment, the COD removal efficiency was obtained as 81.3% with 89.0 kWh/m(3) energy consumption using 0.7 mA/cm(2) current density and 0.2 mM Na2SO4. With the EF method, 99.2% COD removal was achieved with 78.0 kWh/m(3) energy consumption in optimum conditions (0.7 mA/cm(2) current density, 90 mM H2O2, 0.2 mM Na2SO4 at pH 3) after 30-min treatment of wastewater. In EC and EF process, TOC and toxicity of the wastewater were decreased during the treatment period in parallel with COD removal as a result of response surface methodology (RSM) optimization. It was observed that the main metal and heavy metal contents were B, Al, Cr, Zn, Ni, Cu, Cd, and Pb when their concentrations were listed in descending order at the level of mu g/L, and these heavy metal and boron contents were removed more efficiently in the EC process than EF treatment. The FTIR-ATR spectrum of the sludge observed the strong peaks around 875 cm(-1) and 884 cm(-1) related to vibrations of the Fe-O bonds in iron oxide after the EC and EF treatment. This study showed that metal cutting wastewater was successfully treated with EC and EF first time in the literature even if it had high COD, TOC, toxicity, and heavy metal contents.