COD removal efficiency

cutting fluid wastewater

combined Fenton-MBR

operational parameters

COD removal

efficiency

Water treatment

Toxic substances

Biological and chemical treatment

Pollution

Wastewater engineering

Cutting fluid wastewater is a highly concentrated organic effluent generated in the production of silicon water. Because the wastewater that contains synthetic organic compounds is characterized by high COD content, complex components, and poor biodegradability, it is absolutely formidable to be fully treated using one method. Therefore, the combined Fenton-MBR process was developed and explored in this trial, in which some organic compounds such as polyethylene glycol and surfactants can be broken to little pieces by Fenton oxidation and subsequently treated by the MBR process. The operating parameters were tested and optimized respectively, and the process mechanism was revealed as well. Under optimal operating conditions of Fenton oxidation (COD concentration of 2,500 mg/L, reaction temperature of 30ºC, pH of 3.0, Fe²⁺ dosage of 20 mmol/L, H₂O₂ dosage of 250 mmol/L, and treatment time of 3 h) and MBR system (HRT of 8 h, DO of 1 mg/L), COD removal efficiency could reach 97%, and the effluent COD was ultimately reduced to 100 mg/L. The results demonstrated that the combined Fenton-MBR process can solve the defects of MBR, which is arduous to degrade synthetic organic compounds, improving the biodegradability of wastewater and the efficiency of contaminant removal.