Author: Site Editor Publish Time: 21-07-2026 Origin: Site
UV‑C LEDs, with advantages such as solid-state emission, precise wavelength control, mercury-free operation, and instant on/off capability, are gradually replacing traditional low-pressure mercury lamps and chemical disinfectants, becoming a mainstream solution for non-toxic disinfection in recirculating aquaculture systems (RAS). The physicochemical properties of water, radiation parameters of the light source, and microbial self-repair mechanisms are the three key factors determining disinfection efficiency. Existing studies worldwide confirm that UV‑C LEDs in the 265–275 nm range can effectively inactivate common aquaculture pathogens, including bacteria, aquatic viruses, protozoan parasites, and harmful algae, without inducing antibiotic resistance. Based on published experimental data, this paper systematically reviews key influencing factors, pathogen inactivation parameters, current limitations, and future development directions of UV‑C LED disinfection in aquaculture, with all data referenced accordingly.
The effectiveness of UV‑C LED disinfection is influenced by multiple factors, including water quality parameters, radiation characteristics, and reactor design. Complex aquaculture environments—characterized by high turbidity, high organic load, and fluctuating temperatures—can significantly impact inactivation efficiency, requiring parameter optimization to ensure reliable performance.
1.1.1 Turbidity and Suspended Solids
Sediments, residual feed particles, and phytoplankton scatter and absorb UV photons, creating a shielding effect that significantly reduces the effective radiation dose reaching microbial cells .
1.1.2 Organic Matter Content
Dissolved and particulate organic matter, such as feed residues, fecal matter, and humic substances, can encapsulate microorganisms, forming protective layers that both block UV exposure and competitively absorb UV energy, reducing disinfection efficiency .
1.1.3 Water Temperature and Salinity
Aquaculture systems typically operate within a temperature range of 10–30°C and include freshwater (<0.5‰), brackish water (0.5–30‰), and seawater (>30‰). Temperature influences microbial DNA repair activity and UV transmittance, thereby affecting disinfection performance .
UV‑C LEDs inactivate microorganisms by directly damaging nucleic acids, without inducing antimicrobial resistance. Their performance is superior to chemical disinfectants and conventional mercury-based UV systems.
1.2.1 Effective UV Dose
UV dose is the core determinant of microbial log reduction and is positively correlated with inactivation efficiency. Different pathogens exhibit varying UV tolerance thresholds. The optimal wavelength range for aquaculture disinfection is 265–275 nm. Typical inactivation doses are summarized below:
Vibrio parahaemolyticus (marine pathogen): 3-log reduction, 4.8–5.8 mJ/cm²
Vibrio alginolyticus (marine pathogen): 3-log reduction, 8.2–9.7 mJ/cm²
Edwardsiella tarda (broad salinity pathogen): 4-log reduction, 22.8–24.5 mJ/cm²
Salmonella spp. (zoonotic pathogen): 4-log reduction, 26.5–29.0 mJ/cm²
Koi herpesvirus (KHV): 5-log reduction, 39.0–43.0 mJ/cm²
Cryptosporidium oocysts: 3-log reduction, 42–50 mJ/cm²
[2, 4–6]
1.2.2 Irradiation Distance and Uniformity
UV intensity follows the inverse square law. The arrangement and spacing of LED arrays directly affect dose uniformity within the reactor. Insufficient local dosage can create disinfection blind spots.
Microorganisms exposed to UV‑C may repair DNA damage through photoreactivation under visible light by activating photolyase enzymes. This process can significantly reduce disinfection efficacy. Adequate UV dosing and post-treatment light control are critical to suppress photoreactivation .
2.1 Limited Penetration in High-Turbidity Water
Suspended solids and organic matter significantly attenuate UV transmission. Highly turbid aquaculture systems require pre-filtration, increasing infrastructure costs.
2.2 High Cost of High-Power Deep UV LEDs
High-power 270 nm UV‑C LED chips and ceramic packaging remain expensive, making total system costs higher than traditional mercury lamps and limiting adoption among small-scale farmers.
2.3 Insufficient Long-Term Ecological Studies
Most current studies focus on pathogen inactivation. There is limited data on the long-term ecological impact of continuous UV exposure on beneficial microbial communities and plankton, and a lack of standardized application guidelines.
3.1 Multi-Wavelength UV‑C LED Systems
Combining wavelengths such as 222 nm, 265 nm, and 275 nm can improve penetration in turbid water and enhance inactivation across different pathogen types (protozoa, viruses, bacteria).
3.2 Cost Reduction and Efficiency Improvement
Advancements in AlGaN epitaxial growth and localized ceramic packaging are expected to reduce the cost of high-power UV‑C LEDs and improve system affordability.
3.3 Intelligent Disinfection Control Systems
Integration of real-time sensors (turbidity, COD, temperature) with AI algorithms can dynamically adjust LED output and exposure time to deliver precise UV doses based on water quality conditions.
3.4 Lifecycle Ecological Safety Assessment
Long-term in situ studies are needed to evaluate the effects of UV‑C exposure on plankton and nitrifying bacteria, supporting the development of standardized guidelines for aquaculture applications.
With ongoing advancements in third-generation semiconductor materials such as AlGaN, UV‑C LEDs are rapidly emerging as a key technology in sustainable aquaculture. Their advantages—chemical-free operation, no mercury pollution, and no induction of antimicrobial resistance—position them as a superior alternative to traditional disinfection methods. As multi-wavelength systems and intelligent control technologies mature, UV‑C LEDs are expected to become the dominant disinfection solution in both recirculating aquaculture systems and intensive pond farming, supporting disease prevention and sustainable industry development.
