Ozone in Hatcheries and Fish Farm

การตรวจสอบโอโซนในอากาศในโรงเลี้ยงสัตว์ปีกและฟาร์มสัตว์น้ำ – Monitoring Ozone (in the air) in Hatcheries and Fish Farms

ในอุตสาหกรรมการเพาะเลี้ยงสัตว์น้ำเช่นโรงเลี้ยงสัตว์ และฟาร์มสัตว์น้ำ ต้องการใช้น้ำสะอาดเพื่อเพิ่มอัตราการรอดชีวิตของสัตว์น้ำ หากน้ำมีการปนเปื้อนก้อจะเพิ่มความเสี่ยงต่อการติดเชื้อได้ ในโรงเพาะสัตว์ปีก และฟาร์มปลามักจะใช้วิธีการฆ่าเชื้อในน้ำโดยการสร้างโอโซน เพื่อลดความเสี่ยงของการติดเชื้อจากโรคในน้ำซึ่งช่วยเพิ่มอัตราการอยู่รอดสูง อย่างไรก้อตามโอโซนเป็นพิษสูงต่อมนุษย์แต่มีพิษกับสัตว์น้ำในระดับต่ำ มาตรฐานที่กำหนดโดย OSHA อนุญาตให้สัมผัสน้อยกว่า 0.1 mg/L โดยเฉลี่ยถ่วงน้ำหนัก สำหรับระยะเวลาทำงาน 8 ชั่วโมง และสูงสุดที่สามารถสัมผัสได้ 0.3 mg/L ในเวลาไม่เกิน 10 นาที เพื่อความปลอดภัยของมนุษย์ที่มีความเข้มข้นของโอโซนในอากาศ ซึ่งควรจะตรวจสอบในสถานที่ๆอาจจะกลายเป็นที่ปนเปื้อนด้วยโอโซน เช่นโรงเลี้ยงสัตว์ ฟาร์มสัตว์น้ำ เป็นต้น

Hatcheries, fish farms and such in the aquaculture industry require clean water to maintain a high survival rate while rearing aquatic animals. Contaminated water increases the risk of infection which in turn can compromise production. A common way to disinfect water is by generating ozone on-site with an ozone generator. Ozone is a powerful bactericide and viricide that decreases the risk of infection from water borne diseases which helps maintain a high survival rate, aerates the water and leaves no undesirable residues. However, ozone is highly toxic to humans and aquatic animals at very low levels. Standards set by OSHA allow a permissible exposure level of less than 0.1 mg/L on a time-weighted average for an 8 hour work period and a maximum single exposure level of 0.3 mg/L for less than a 10 minute duration.

For human safety, the ozone concentrations in the air should be monitored in the locations that could become contaminated with ozone. A typical ozone system for a hatchery operation has an ozone generator and three chambers. The ozone generator creates ozone which is then introduced into the first tank, the counter flow diffusion chamber. Here the oxidization of dissolved matter occurs. The first ozone gas detector should be installed in the ozone generator room to monitor for potential leaks around the ozone generator and piping structures. If the gas detector were to go into alarm, it can be configured to shut off the ozone generator, stopping the production of ozone. In addition, the ventilation and make-up air fans can be triggered to come on and go off at set intervals, including when the gas detector goes into alarm. The second chamber is the reaction or contact tank where the disinfection of the water and slow chemical reactions occur. Depending on the operation setup, the second chamber may be in the ozone generator room or in another room or general area. From the contact tank, the water gets sent to the third chamber which completes the slow reactions and the majority of the residual ozone decomposes. Any undissolved or residual ozone gas is collected and vented by way of the ozone destruction process which will destroy the ozone in the gas before releasing it into the atmosphere. A second ozone gas detector should be installed near the ozone destructor to monitor the exhaust air stream to ensure the ozone destructor is operating effectively.

CETCI’s LPT-A-O3 Ozone Gas Detector offers a fixed, continuous gas monitoring solution for hatcheries, fish farms and other aquaculture operations that use ozone to clean the water. Use as a standalone system, or combine up to four ozone gas detectors with our QCC Quad Channel Controller for larger applications. Each LPT-A-O3 transmitter features an audible alarm, LCD display with real time gas readings and a programmable relay to shut down the ozone generator. When combined with a QCC Controller, three more relays are available for triggering safety events such as switching on/off ventilation fans or make-up air fans and/or activating a remote strobe/horn. More value-added features available are two analog outputs, a data logger, manual equipment ON/OFF switch, top mounted strobe, remote strobe and horn combo and remote display module that offers the ability to view the gas level readings in a separate location from the controller and transmitters.

Ozone is a very reactive gas and can quickly corrode metals and damage plastic materials. There should be regular maintenance checks of pipe fittings, gaskets and seals all along the ozone injection system. In addition to a fixed gas detection system, it is also recommended that portable handheld monitors be used to do spot checks for leaks around piping and in poorly ventilated areas. If there is an equipment malfunction, or if tubing’s and fittings leak, or too much ozone is being produced, a properly installed ozone gas detector system will alarm and shut down the ozone generator before a dangerous environment is created and the health and safety of the workers is jeopardized.