Liu Shihong, Abu Hajar Husam A, Riefler Guy, Stuart Ben J
Department of Chemical and Biomolecular Engineering, Ohio University Athens OH 45701 USA
Civil Engineering Department, School of Engineering, The University of Jordan Amman Jordan.
RSC Adv. 2018 Nov 19;8(68):38808-38817. doi: 10.1039/c8ra08101h. eCollection 2018 Nov 16.
Electrolytic flocculation using non-sacrificial electrodes with flocculants added was studied on harvesting sp. In order to optimize the operating conditions of the electrolytic flocculation process and to quantify the amount of flocculants added, aluminum electrodes were first used in the process. It was found that under optimal conditions, the microalgae removal efficiency using aluminum electrodes could reach 98.5%, while 34.2 mg L of aluminum ions were released during the process. Different metal electrodes were also studied, but high microalgae removal efficiency was witnessed only using aluminum electrodes, indicating the influence of the aluminum ion in flocculation. When non-sacrificial graphite electrodes were used in the electrolytic flocculation process, the corresponding amount of aluminum sulfate was added so that the aluminum ion concentration in water was also equal to 34.2 mg L. The result showed that the microalgae removal efficiency of graphite electrodes could reach above 90% after aluminum sulfate was added. In contrast, using graphite electrodes alone and using the metal salt alone only yielded 22.9% and 7.1% of microalgae removal efficiency, respectively. These results indicated that the presence of metal ions is necessary in the electrolytic flocculation process. The energy consumption of the process was found to be 0.3 kW h m or 0.88 kW h kg, which is considered to be low energy consumption. The total cost of the process, including energy and chemicals, was found to be $ 0.21 m, proving a cost competitive method in microalgae harvesting.
研究了使用非牺牲电极并添加絮凝剂的电解絮凝法用于收获微藻。为了优化电解絮凝过程的操作条件并量化添加的絮凝剂的量，该过程首先使用铝电极。结果发现，在最佳条件下，使用铝电极的微藻去除效率可达98.5%，而在此过程中会释放出34.2 mg/L的铝离子。还研究了不同的金属电极，但仅使用铝电极时微藻去除效率较高，这表明铝离子在絮凝过程中的影响。当在电解絮凝过程中使用非牺牲石墨电极时，添加相应量的硫酸铝，使水中铝离子浓度也等于34.2 mg/L。结果表明，添加硫酸铝后石墨电极的微藻去除效率可达到90%以上。相比之下，单独使用石墨电极和单独使用金属盐时微藻去除效率分别仅为22.9%和7.1%。这些结果表明，金属离子的存在在电解絮凝过程中是必要的。该过程的能耗为0.3 kW·h/m³或0.88 kW·h/kg，被认为是低能耗。该过程的总成本，包括能源和化学品，为0.21美元/m³，证明是一种在微藻收获方面具有成本竞争力的方法。
