comparing the performance of uv/acetylacetone and uv/o3 processes for treatment of olive mill wastewater

Background: olive mill wastewater (omw) is characterized by its high organic content and refractory compounds. the aim of this study was to evaluate and compare the efficiency of uv/o3 and uv/ acetylacetone (uv/acac) processes for treatment of pretreated omw by coagulation/microfiltration (c&m) process.methods: in this study, a laboratory-scale uv plug flow reactor with ancillary equipment was fabricated. the experimental factors including initial ph (5-9), o3 dosages (1.5-4.5 g/h), and acac concentrations (0.01-0.03 m) were measured. for both processes, a reaction time of 120 min was considered. the effect of these variables on removal of wastewater contaminants including bod, cod, tss, turbidity, phenol, oil, and grease were investigated.results: results showed that raw omw has a high load of pollutants and very low biodegradability (bod5/cod = 0.12). in uv/o3 process, the optimal conditions were obtained at ph 8 and ozone injection at 4 g/h. the combined c&m-uv/o3 process removed 78.75% cod, 46.66% bod5, 90.88% total phenol, 91.78% tss, 99.14% oil and grease, and 98.38% turbidity, with promotion of bod5/ cod from 0.12 to 0.33. in uv/acac process, the optimal conditions were achieved at ph 5 and acac concentration of 0.03 m. the combined c&m-uv/acac process removed 58.75% cod, 67.58% bod5, 38.03% total phenol, 83.50% tss, 93.65% oil and grease, and 95.00% turbidity, with promotion of bod5/ cod from 0.12 to 0.22.conclusion: the results showed that the uv/o3 process is completely superior to the uv/acac process for removal of omw contaminants, as well as promoting the biodegradability of omw.