A Case Study of Dye Intermediate Production Wastewater Treatment Project

Abstract

Dye intermediates are indispensable chemical raw materials and play an important role in global industrial production. In the production process of dye intermediates, a large amount of wastewater is produced, which will cause serious pollution to the environment, and ultimately harm human health. Dye intermediate production wastewater is characterized by high organic matter concentration, complicated pollutants and poor biodegradability. The traditional treatment process has limited ability to purify wastewater and can not effectively degrade the organic pollutants. In this project, a novel combined process of "ozone catalytic oxidation + biochemical degradation" was adopted to treat the dye intermediate production wastewater, and the process mechanism and treatment effect were analyzed. The results showed that the key process unit of this project was heterogeneous ozone catalytic oxidation. Due to the high activity, low cost, easy recovery and strong adsorption capacity of heterogeneous ozone catalysts, a large amount of organic matters in wastewater could be adsorbed on the surface to improve the treatment effect. Through the oxidation process, the biodegradability of wastewater was improved to facilitate subsequent advanced treatment. Ultimately, the effluent water quality could meet the three-level limit requirements in the "Integrated Wastewater Discharge Standard" (GB8978-1996), with the water index as follows: CODcr≤450 mg/L, BOD₅≤200 mg/L, SS≤200 mg/L, chromatic value≤32 times. This operational process was manifested to be economical and reliable, possessing a broad development prospect in wastewater treatment of dye intermediates related industries.