Electrocoagulation pretreatment of seawater prior to ultrafiltration: Bench-scale applications for military water purification systems
| Autor: | Thomas C. Timmes, Hyun-Chul Kim, Brian A. Dempsey |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Flocculation
Chemistry Mechanical Engineering General Chemical Engineering medicine.medical_treatment Ultrafiltration Environmental engineering Portable water purification General Chemistry Pulp and paper industry Chloride Electrocoagulation Membrane technology medicine Ferric General Materials Science Water treatment Water Science and Technology medicine.drug |
| Zdroj: | Desalination. 249:895-901 |
| ISSN: | 0011-9164 |
| Popis: | The objectives were to investigate the performance of a pilot-scale electrocoagulation (EC) reactor and to determine the feasibility of using in-line EC as a pretreatment to ultrafiltration (UF) of seawater. Work was conducted at Port Hueneme, CA, using components of a U.S. military water purification system. Ferric chloride in-line coagulation was also tested. Both the EC and ferric chloride pretreatments improved UF membrane performance compared to UF without in-line coagulation. EC resulted in slightly greater increases in transmembrane pressure (TMP) than observed following ferric chloride pretreatment during sub-critical flux UF. Substantial accumulation of precipitates developed on the EC electrodes during the testing period. X-ray diffraction identified magnetite, maghemite, lepidocrocite, and akaganeite phases. Accumulation of these precipitates was due in part to conservative hydraulic design of the EC unit. It is recommended that EC units should be designed with short hydraulic retention times and higher electrode current density in order to increase upflow (scour) velocity and thus inhibit accumulation on the electrodes. Progressively longer cycling times for polarity reversal are also recommended. This research indicates that EC offers the potential for a feasible and effective pretreatment strategy for mobile water production facilities. |
| Databáze: | OpenAIRE |
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