Water Desalination and Reuse Center (WDRC), Division of Biological & Environmental Science & Engineering (BESE), 4700 King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Water Desalination and Reuse Center (WDRC), Division of Biological & Environmental Science & Engineering (BESE), 4700 King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia.
Sci Total Environ. 2019 Oct 1;685:1193-1200. doi: 10.1016/j.scitotenv.2019.06.286. Epub 2019 Jun 19.
Harmful algal blooms (HABs) are considered a major threat for seawater reverse osmosis (SWRO) plants. The presence of HABs in the raw feed water can cause increase of chemical consumption within the desalination plant, increase membrane fouling rate and might lead to plant shutdown. The removal of Algal Organic Matters (AOMs) during the pretreatment will help in increasing the membrane lifetime, reduce operation cost and increase the plant reliability. In this study, the efficiency of liquid ferrate and ferric chloride during coagulation on the removal of AOMs was investigated. The liquid ferrate was generated in-situ by wet oxidation of ferric iron using hypochlorite in a caustic medium. Two seawater models were employed, the first one contains 10 mg c/L of sodium alginate and the second one contains also 10 mg c/L of Chaetoceros affinis algae (CA). During the advanced coagulation, liquid ferrate proved to be more effective in removing AOM than ferric chloride, with an overall DOC removal of 90%, enabling 100% algal removal and the inactivation of 99.99% of the microorganisms. The results presented in this study highlights the efficiency of liquid ferrate as seawater pretreatment during the HABs events.
有害藻华 (HABs) 被认为是海水反渗透 (SWRO) 工厂的主要威胁。原水中 HABs 的存在会导致海水淡化厂化学药品消耗增加，膜污染速率增加，甚至导致工厂停机。在预处理过程中去除藻源有机物 (AOM) 将有助于延长膜的使用寿命、降低运行成本和提高工厂可靠性。本研究考察了液体高铁酸盐和三氯化铁在混凝过程中去除 AOM 的效果。液体高铁酸盐通过在碱性介质中用次氯酸盐氧化铁原位生成。采用两种海水模型，第一个模型中含有 10mg c/L 的海藻酸钠，第二个模型中还含有 10mg c/L 的菱形藻 (CA)。在高级混凝过程中，液体高铁酸盐在去除 AOM 方面比三氯化铁更有效，总 DOC 去除率达到 90%，可实现 100%的藻类去除和 99.99%的微生物失活。本研究结果突出了液体高铁酸盐作为 HABs 事件期间海水预处理的效率。
