کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4988748 | 1455961 | 2017 | 8 صفحه PDF | دانلود رایگان |
- Ozonation is effective in alginate-related ceramic membrane fouling control.
- Pre-ozonation achieves better fouling mitigation performance at low ozone dosage.
- In-situ ozonation achieves better fouling control performance at high ozone dosage.
- Cake-complete model best fits the alginate-related membrane fouling.
- The ÎTMP is maintained below 0.2Â kPa at high in-situ ozonation dosage of 10Â mg/L.
Pre-ozonation or in-situ ozonation coupled with membrane filtration has been actively utilized for membrane fouling control in water treatment, however, the comparative analysis of these two ozonation processes on membrane fouling control has not been reported so far. In this study, the comparative effect of pre-ozonation and in-situ ozonation on mitigation of ceramic UF (ultrafiltration) membrane fouling caused by alginate was systematically investigated through characterization of TMP, fouling resistance, MW distribution, dissolved ozone concentration, the formation of hydroxyl radical and modeling. Results showed that both pre-ozonation and in-situ ozonation were effective in alleviating the cake layer fouling. Ozonation efficiently broke down the high molecular weight (MW) fractions (>150Â kDa and 80-150Â kDa) of alginate into the low MW fractions (6-80Â kDa; 0.4-6Â kDa and 0.1-0.4Â kDa), reducing the membrane interception of alginate. Pre-ozonation achieved better fouling mitigation performance compared with in-situ ozonation at low ozone dosages of 2 and 4Â mg/L. However, in-situ ozonation had better fouling control performance at high ozone dosage of 10Â mg/L with the normalized TMP (ÎTMP) maintaining below 0.2 kPa after 60Â min filtration. Besides, in-situ ozonation was more effective in hydraulically irreversible fouling control than pre-ozonation regardless of ozone dosage. Integration of in-situ ozonation and ceramic membrane filtration catalyzed ozone decomposition with the increased generation of hydroxyl radical, which further strengthened the oxidation of the accumulated foulants on the membrane surface and within the membrane pores and thus effectively alleviated the reversible and irreversible fouling.
Journal: Journal of Membrane Science - Volume 538, 15 September 2017, Pages 50-57