Wastewater treatment system using electrochemical oxidation and membrane distillation, and wastewater treatment method using the same

Wastewater treatment system recycling persulfate from electrochemical oxidation and excess reaction heat for membrane distillation

This technology is a wastewater treatment system and method that introduces organic wastewater into a sulfuric acid electrolyte to trigger an electrochemical reaction, simultaneously generating persulfate oxidants and excess oxidation heat, and then directs the heated electrolyte to a membrane distillation unit to separate clean water.

Chemical wastewater treatment often causes secondary environmental pollution due to excessive chemical use. While electrochemical treatment has emerged as an alternative capable of processing high-concentration wastewater in compact units, it traditionally required high electrolyte concentrations to reduce resistive heating, necessitating an additional separation process after oxidation.

This technology utilizes a reaction tank equipped with a boron-doped diamond (BDD) anode and a cathode packed with metal oxides such as TiO2. It oxidizes pollutants directly and indirectly using persulfate without external oxidants, and leverages the vapor pressure difference between the 40–70°C electrolyte and cooling water to pass only water vapor through a hydrophobic membrane. Membranes such as PVDF, PE, PP, or PTFE can be used. Applicable to industrial wastewater containing recalcitrant organic matter, leachate, concentrate treatment, and high-concentration waste recycling in semiconductor and chemical plants, it enables pollutant degradation and high-quality water recovery in a single step without external heat or oxidants.

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Key Features:

• An electrochemical reactor where organic wastewater is added to a sulfuric acid-based electrolyte to generate persulfate and excess oxidation heat through electrochemical reactions
• A boron-doped diamond anode and a cathode packed with metal oxides selected from TiO2, UO2, Ta2O5, and U3O8, provided within the reaction tank
• A membrane distillation unit that receives the electrolyte after the electrochemical reaction and filters it through a membrane distillation process
• A membrane that allows water to evaporate and permeate through a hydrophobic barrier due to the vapor pressure difference between the electrolyte heated by excess oxidation heat and the cooling water

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This invention was developed with support from the National Research Foundation of Korea for the development of low-cost, non-precious metal electrocatalysts for water treatment and simultaneous hydrogen production.

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