FENTON AND FENTON-LIKE AOPs FOR ALUM SLUDGE CONDITIONING: EFFECTIVENESS COMPARISON WITH DIFFERENT Fe2+ AND Fe3+ SALTS |
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Authors: | Maha A. Tony Y. Q. Zhao M. F. El-Sherbiny |
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Affiliation: | 1. Centre for Water Resources Research, School of Architecture, Landscape and Civil Engineering, University College Dublin , Dublin, Ireland maha_tony1@yahoo.com;3. Centre for Water Resources Research, School of Architecture, Landscape and Civil Engineering, University College Dublin , Dublin, Ireland;4. Basic Engineering Science Department, Faculty of Engineering , Minoufiya University , Minoufiya, Egypt |
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Abstract: | Currently, organic polymers are adopted in alum sludge (aluminum-coagulated drinking water treatment sludge) conditioning. However, there are important concerns regarding the use of these polymers because of the unknown and long-term effects of the potential release of excess polymer to the surrounding environment when the sludge is landfilled. Therefore, as an initial action, this study aimed at investigating alternative chemical conditioning methods and focused mainly on exploiting Fenton (Fe2+/H2O2) and Fenton-like (Fe3+/H2O2) reagents as the conditioner. Experiments have been conducted to test the effectiveness of Fenton's reagent (containing the ferrous salts of chloride, sulfate, or oxalate), Fenton-like reagent (containing ferric salts of chloride and sulfate), and the coagulation method using FeCl3 for alum sludge conditioning at constant hydrogen peroxide and iron salt concentrations of 125 and 20 mg/g DS (dry solids), respectively. The effectiveness on dewaterability of the alum sludge demonstrated that the maximum reduction (%) of SRF (specific resistance to filtration) and CST (capillary suction time) of 74% and 47%, respectively, can be obtained when Fenton's reagent was adopted for sludge conditioning. Such reduction of 64% for SRF and 38% for CST can be achieved when Fenton-like reagents were applied. |
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Keywords: | Alum sludge Capillary suction time (CST) Conditioning Fenton-like process Fenton's reagent Specific resistance to filtration (SRF) |
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