Factors affecting treatment of TFT-LCD wastewater by fenton and electro-fenton processes

摘要

The TFT-LCD screen (thin film transistor liquid crystal display) industry has been growing rapidly in Taiwan in recent years. The wastewater from this industry contains many non-biodegradable pollutants and high strength nitrogen and sulfur containing compounds which are difficult to degrade. Fenton and electro-Fenton with double-cathode processes were used to treat the high COD content of real TFT-LCD wastewater which cannot be removed by conventional processes. The effect of operating parameters such as pH, Fe2+, H2O2 concentration and electrical current on COD removal were determined. The electro-Fenton process rapidly degraded the TFT-LCD wastewater in the first 20 minutes while in the Fenton process, the rapid degradation occurred in the first 60 min. This showed that electro-Fenton process could degrade the TFT-LCD wastewater faster than the Fenton process. The highest COD removal efficiency was found to be 100% at 120 min at pH=4, [Fe2+]=3.5 mM, [H2O2]=285 mM and 1.5 A of electrical current of electro-Fenton process. (c) 2015 American Institute of Chemical Engineers Environ Prog, 35: 368-373, 2016