Treatment of H-acid wastewater by photo-Fenton reagent combined with a biotreatment process: A study on optimum conditions of pretreatment by a photo-Fenton process

摘要

The oxidation efficiency of a photo-Fenton reagent system can be enhanced significantly when UV or visible light is introduced into the system (Lipczynska-kochany 1991). Thus, among the advanced oxidation processes, the oxidation technique based onUV or visible light shows promise in the application of the treatment of toxic and refractory organic wastewater and non-biodegradable industrial wastewater (Oliveros et al. 1997, Zhu et al. 1996, Pignatello and Sun 1995), and has demonstrated by full-scale applications in Western countries (Pignatello 1992). 1-Amino-8-naphthol-3,6-disulfonic acid (H-acid) containing wastewater is one of the most important pollutants in industries producing acidic and active dyestuff and medicine. H-acid is highly toxicto microbe, and it is difficult to treat H-acid wastewater by a biological process (Chen and Pignatello 1997). Presently, a wet catalytic oxidation process has been successfully adopted to treat this kind of wastewater which contains a high concentration of H-acid. However, its strict operation conditions and high primary investment hinder its wider application for the treatment of H-acid wastewater of low CODer values. In recent years, increasing attention has been paid to photo-catalytic processes, which have certain obvious advantages in the treatment of low concentration bio-refractory organic wastewater. In this study, the UV-Fenton reagent system was employed to pretreat bio-refractory H-acid wastewater with a CODer of 300-500 mg/L. Optimal conditions suitable for diminishing COD_(cr), as well as the biodegradability of the effluent, has been investigated.