Department of Environmental Technologies, Faculty of Marine and Environmental Sciences, INMAR-Marine Research Institute, CEIMAR- International Campus of Excellence of the Sea, University of Cadiz, Spain; Grupo de Procesos de Oxidación Avanzada, Departamento de Ingeniería Textil y Papelera, Universitat Politècnica de València, Campus de Alcoy, Alcoy, Spain.
Department of Separation Science, School of Engineering Science, Lappeenranta-Lahti University of Technology LUT, Sammonkatu 12, 50130 Mikkeli, Finland.
Water Res. 2020 Aug 15;181:115928. doi: 10.1016/j.watres.2020.115928. Epub 2020 May 14.
The development of technologically advanced recirculation aquaculture systems (RAS) implies the reuse of water in a high recirculation rate (>90%). One of the most important phases for water management in RAS involves water disinfection in order to avoid proliferation of potential pathogens and related fish diseases. Accordingly, different approaches have been assessed in this study by performing a comparison of photolytic (UV-LEDs) at different wavelengths (λ = 262, 268 and 262 + 268 nm), photochemical (UV-LEDs/HO, UV-LEDs/HSO and UV-LEDs/SO) and photocatalytic (TiO/SiO/UV-LEDs and ZnO/SiO/UV-LEDs) processes for the disinfection of water in RAS streams. Different laboratory tests were performed in batch scale with real RAS stream water and naturally occurring bacteria (Aeromonas hydrophyla and Citrobacter gillenii) as target microorganisms. Regarding photolytic processes, higher inactivation rates were obtained by combining λ in front of single wavelengths. Photochemical processes showed higher efficiencies by comparison with a single UV-C process, especially at 10 mg L of initial oxidant dose. The inactivation kinetic rate constant was improved in the range of 15-38%, with major efficiency for UV/HO ∼ UV/HSO > UV/SO. According to photocatalytic tests, higher efficiencies were obtained by improving the inactivation kinetic rate constant up to 55% in comparison with a single UV-C process. Preliminary cost estimation was conducted for all tested disinfection methods. Those results suggest the potential application of UV-LEDs as promoter of different photochemical and photocatalytic processes, which are able to enhance disinfection in particular cases, such as the aquaculture industry.
技术先进的循环水养殖系统 (RAS) 的发展意味着水的高循环率 (>90%) 再利用。RAS 中的水管理最重要的阶段之一涉及水的消毒，以避免潜在病原体和相关鱼类疾病的增殖。因此，本研究通过比较不同波长的光解（UV-LEDs，λ=262、268 和 262+268nm）、光化学（UV-LEDs/HO、UV-LEDs/HSO 和 UV-LEDs/SO）和光催化（TiO/SiO/UV-LEDs 和 ZnO/SiO/UV-LEDs）过程，评估了不同的方法来对 RAS 水流进行消毒。在实验室规模的批处理实验中，使用实际的 RAS 水流和天然存在的细菌（嗜水气单胞菌和吉尔氏柠檬酸杆菌）作为目标微生物进行了不同的实验。关于光解过程，通过组合单一波长前的 λ 可以获得更高的灭活率。与单一 UV-C 工艺相比，光化学工艺显示出更高的效率，特别是在初始氧化剂剂量为 10mg/L 时。灭活动力学速率常数提高了 15-38%，其中 UV/HO~UV/HSO>UV/SO 的效率更高。根据光催化测试，与单一 UV-C 工艺相比，通过提高灭活动力学速率常数，可获得高达 55%的更高效率。对所有测试的消毒方法进行了初步成本估算。这些结果表明，UV-LED 可作为不同光化学和光催化过程的促进剂，在某些情况下（如水产养殖行业）能够增强消毒效果。
