Ozone in RAS Systems

Ozone in RAS

Ozone in RAS Systems

Aquaculture, the practice of cultivating aquatic organisms, has become increasingly important in meeting the world’s growing demand for fish. However, traditional open-water fish farming faces challenges related to water quality, environmental impact, and resource scarcity. This is where Recirculating Aquaculture Systems (RAS) come into play.

What Are Recirculating Aquaculture Systems (RAS)?

RAS are advanced indoor tank-based systems designed for fish cultivation under controlled conditions. Here are the key features of RAS:

  1. Controlled Environment: RAS provides a fully controlled environment for fish, allowing precise management of water quality, temperature, and other parameters.
  2. Water Efficiency: Unlike traditional flow-through systems, RAS significantly reduces water consumption by recirculating and treating water within the system.
  3. Energy Efficiency: RAS optimizes energy use through efficient pumps, filters, and monitoring systems.
  4. Land Use: RAS systems utilize space efficiently, making them suitable for urban and land-constrained areas.
  5. Intensive Production: RAS allows high-density culture, maximizing fish production per unit area.
  6. Environmental Control: By minimizing environmental impact and effluent volumes, RAS contributes to sustainable aquaculture.

The Importance of RAS in Meeting Global Fish Needs

Challenges in Traditional Aquaculture

Traditional aquaculture faces several challenges:

  • Regulatory Hurdles: Expanding open-water aquaculture is often hindered by regulations and environmental concerns.
  • Water Scarcity: Access to clean water is limited, especially in densely populated regions.
  • Environmental Impact: Effluent discharge from traditional systems can harm ecosystems.

How RAS Addresses These Challenges

RAS offers solutions to these challenges:

  1. Local Production and Food Security:

    • In Europe, for instance, RAS enables increased local fish production. This reduces import dependence and enhances food security.
    • RAS systems can be established near urban centres, minimizing transportation costs and ensuring fresh fish supply.
  2. Species Adaptability:

    • RAS can be adapted to various aquaculture species, including both freshwater and marine fish.
    • While cost considerations play a role, RAS allows flexibility in species selection.

Ozone in RAS Systems: Benefits and Usage

Ozone, a powerful oxidizing agent, plays a pivotal role in RAS systems:

  1. Organic Waste Removal:

    • Ozone breaks down fine colloidal solids and dissolved organic compounds (DOCs).
    • This enhances water quality by facilitating their removal through filtration and sedimentation.
    • Improved water clarity benefits fish health and overall system performance.
  2. Nitrite Conversion:

    • Nitrite accumulation can be problematic in RAS.
    • Ozone helps convert harmful nitrite (NO₂⁻) to nitrate (NO₃⁻), which is less toxic to fish.
    • This process, known as oxidation, occurs in the presence of ozone.
  3. Pathogen Disinfection:

    • Ozone sterilizes supply and effluent water, reducing the risk of disease transmission.
    • It targets bacteria, viruses, and other pathogens, contributing to healthier fish populations.

Determining Ozone Requirement in RAS

The required ozone amount depends on factors such as fish species, system size, and water quality. Here’s how it’s determined:

  1. Daily Feed Rate:

    • Ozone dosage is often calculated based on the daily feed rate (amount of feed given to fish).
    • Recommended rates range from 10-15 grams of ozone per kilogram of feed.
  2. Redox Potential (ORP):

    • Monitoring the redox potential (ORP) helps maintain optimal ozone levels.
    • For freshwater RAS, an ideal ORP level is around 300 mV.

Harnessing the power of ozone in RAS (Recirculating Aquaculture Systems) and efficient management, these systems promise sustainable fish production. They bridge the gap between demand and supply, ensuring a healthier future for both fish and humans. As we explore innovative solutions, “ozone in RAS” remains at the forefront of responsible aquaculture practices.