Determination of optimum operational conditions for the removal of 2-MIB from drinking water by peroxone process: a pilot-scale study

Abstract

<jats:title>Abstract</jats:title> <jats:p>Taste and odor in drinking water are one of the main problems of water supply and treatment sector. Peroxone is an effective advanced oxidation process, which combines ozone with hydrogen peroxide to create hydroxyl radicals that decompose organic compounds. 2-Methylisoborneol (2-MIB) is one of the significant taste and odor causing compounds, which can be removed with peroxone process. In this study, removal of 2-MIB compound by peroxone process was investigated in a pilot scale treatment plant and optimum operational conditions were determined. For safety reasons, it is important that residual O3 and H2O2 concentrations in the water leaving the reactor should not exceed to 0.1 and 0.5 mg/L, respectively. Results indicate that while dissolved ozone concentration was below the indicated limit for all experiments, concentrations over 0.5 mg/L residual H2O2 were observed during the experiments with a H2O2:O3 ratio of 0.5. This limit exceedance affected the decision of the ideal peroxone ratio along with the 2-MIB removal results. Therefore; optimum H2O2:O3 ratio was determined as 0.3. 2-MIB removal efficiency of 81% was achieved at the optimum H2O2:O3 ratio with a contact time of 15 min. According to the results, 2-MIB removal rate had a linear correlation with the contact time.</jats:p>

Degradation of Odor Compounds in Drinking Water by Ozone and Ozone-Based Advanced Oxidation Processes: A Review

“…As for low NOM-containing ones, the greater the ratio, the better the obtained results (the ratio in the range of 0–0.5) . Considering the problem of residual H 2 O 2 which is recommended to remain lower than 0.5 mg L –1 , Fakioglu et al suggested that the optimal ratio of H 2 O 2 /O 3 was about 0.3 …”

“…Koch et al suggested that the removal rates of odor compounds were independent of the contact time with the oxidizer; 153 these results were contradicted by the work conducted by Fakioglu et al, where removal rates were linearly correlated to the contact time. 154 The determination of the optimal ratio of H 2 O 2 /O 3 is an important problem to be solved in practical applications. For high-NOM source water, the optimal H 2 O 2 /O 3 ratio for eliminating GSM and 2-MIB is about 0.1−0.2.…”

“…153 Considering the problem of residual H 2 O 2 which is recommended to remain lower than 0.5 mg L −1 , Fakioglu et al suggested that the optimal ratio of H 2 O 2 /O 3 was about 0.3. 154 Previous studies have shown that enhanced coagulation by preozonation can effectively eliminate odor issues by removing algal cells, which can be explained by the reduction of cell zeta potential but with simultaneous preservation of the cell integrity observed at low dose ozone concentrations (typically less than 1 mg L −1 ). 110,155 The removal rate of Microcystis aeruginosa (10 6 CFU mL −1 ) by sedimentation was above 70% when preozonation at an ozone dose of 0.4−2 mg L −1 was applied, 156 whereas an 80.2% algal sedimentation rate was achieved using ozonation at 0.2 mg L −1 followed by coagulation and sedimentation.…”

“…The results obtained from the study indicated that when peroxone technology with 2 mg L –1 O 3 at an H 2 O 2 :O 3 ratio of 0.2 was adopted for preoxidation, the pollutant’s removal rate can reach 80–90%, which was the same as the removal rate with ozonation alone with 4 mg L –1 O 3 . Koch et al suggested that the removal rates of odor compounds were independent of the contact time with the oxidizer; these results were contradicted by the work conducted by Fakioglu et al, where removal rates were linearly correlated to the contact time …”