EVALUATION OF UV/O₃ AND UV/H₂O₂ PROCESSES FOR NONBIODEGRADABLE COMPOUNDS: IMPLICATIONS FOR INTEGRATION WITH BIOLOGICAL PROCESSES FOR EFFLUENT TREATMENT

Poorly biodegradable compounds reduce the efficiency of biological effluent treatment processes. These are often encountered in pharmaceutical and speciality chemical industries. Advanced oxidation technologies (AOT) are appropriate for the conversion of such compounds into biodegradable entities. Tetrahydrofuran, 1,4-dioxane, and pyridine are heterocyclic compounds that are known to be recalcitrant and nonbiodegradable. AOT were investigated for the destruction of these model compounds. Two forms of AOT, UV-O₃ and UV-H₂O₂, were studied. UV-H₂O₂ treatment resulted in higher biodegradability for tetrahydrofuran; UV-O₃ treatment resulted in higher biodegradability for 1,4-dioxane. For pyridine, neither treatment improved biodegradability. For efficient integration of AOT with biological processes for effluent treatment, it is necessary to evaluate the AOT with multiple objectives, such as level of destruction of target compound, level of reduction in COD, and enhancement of biodegradability. Due to the presence of multiple pollutants in real effluents and in AOT, kinetics of oxidation elucidated with single compounds is unlikely to be useful.

Keywords:

• Advanced oxidation
• Biological treatment
• Recalcitrant chemicals