Hybrid electrocoagulation/electroflotation/electrodisinfection process as a pretreatment for seawater desalination
Hybrid electrocoagulation/electroflotation/electrodisinfection process as a pretreatment for seawater desalination
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DOI：
10.1016/j.ces.2017.04.029
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发表时间：
2017-10-12
影响因子：
4.7
通讯作者：
Naja, Jamal
中科院分区：
文献类型：
--
作者：
Hakizimana, Jean Nepo;Najid, Noura;Naja, Jamal
本研究的主要目的是探讨电凝聚/电絮凝/电消毒（EC/EF/艾德）复合工艺在反渗透海水淡化前处理海水的可行性。测定了残余溶解有机碳（DOC）和异养细菌浓度。研究了使用铝电极的连续处理，其导致复杂的气-液-固混合物，其中铝絮凝物和氢气气泡增强污染去除。实验结果表明，DOC去除率随电流密度的增大而增大，随进水流量的减小而减小。当进水pH为4，电流密度为20 mA/cm（2），停留时间为320 s时，DOC去除率最高，为69.0%。在最高电流密度（20 mA/cm（2））下，异养细菌被完全去除。在EC过程中，一个低浓度的总氯物种（高达0.45 mg/L）的氯阴离子的氧化所产生的形成，这促进了微生物的去除，即使这些主要是通过电场和氢氧化物絮凝体中的细菌截留的耦合效应。最后，EC/EF/艾德作为一个一步预处理方法被证明是有效的，以取代传统的方法，然后通过反渗透脱盐，因为它被证明是有效地去除有机物和微生物从海水中：与0.8 L/h和14 mA/cm（2），50%的DOC和几乎所有的微生物可以被去除在小于0.5 kW h/m（3）。(C)2017爱思唯尔有限公司版权所有。
The main objective of this study was to examine the feasibility of a hybrid electrocoagulation/electroflo tation/electrodisinfection (EC/EF/ED) process in treating seawater prior to desalination treatment using reverse osmosis process. Residual dissolved organic carbon (DOC) and heterotrophic bacteria concentrations were measured. A continuous treatment using aluminium electrodes was investigated, which lead to a complex gas-liquid-solid mixture in which aluminium flocs and hydrogen gas bubbles enhanced pollution removal. Experimental results showed that DOC removal efficiency increased when the current density increased and when the inlet flow rate decreased, The best performance of DOC removal (69.0%) was recorded while imposing 20 mA/cm(2) and 320 s residence time when inflow pH was 4. Heterotrophic bacteria were completely removed for the highest current densities (20 mA/cm(2)). In the EC process, a low concentration of total chlorine species (up to 0.45 mg/L) resulting from the oxidation of chloride anions was formed, which promoted the removal of microorganisms, even though these were mainly removed by the coupled effects of the electric field and the bacteria entrapment in hydroxide flocs. Finally, EC/EF/ED as a one-step pretreatment method was shown to be efficient to replace the conventional methods prior to desalination by reverse osmosis as it was proved to remove efficiently organic matter and microorganisms from seawater: with 0.8 L/h and 14 mA/cm(2), 50% of DOC and nearly all the microorganisms could be removed at less than 0.5 kW h/m(3). (C) 2017 Elsevier Ltd. All rights reserved.