Description

Refined oil in water refers to petroleum products that have undergone processing, such as gasoline, diesel, kerosene, jet fuel, and lubricating oils. Unlike crude oil, which is a complex mixture, refined oils are typically lighter, more volatile, and can pose significant environmental and health risks even at low concentrations. Their presence in water bodies indicates contamination, often from spills, leaks, or improper disposal.

Why is Refined Oil Monitoring Important?

Monitoring refined oil levels in water is critical for environmental protection, public safety, and regulatory compliance

• Environmental Damage: Refined oils can be highly toxic to aquatic life, disrupting ecosystems. They can coat flora and fauna, impairing respiration, feeding, and reproduction, and can accumulate in the food chain.
• Human Health Risks: Contaminated water can pose direct health risks if ingested or through skin contact. Volatile components can also create respiratory hazards.
• Drinking Water Contamination: Spills or leaks of refined oil can severely impact drinking water sources, requiring extensive and costly treatment or rendering the source unusable.
• Infrastructure Damage: Certain refined oils can corrode pipes and infrastructure, leading to further leaks and system failures.
• Regulatory Compliance: Environmental regulations worldwide mandate limits on oil and grease in discharges and receiving waters. Monitoring helps industries and municipalities ensure compliance and avoid penalties.
• Source Identification: Detecting refined oil can help trace the source of pollution, enabling rapid response and remediation efforts.
• Aesthetic Impact: Even at low concentrations, refined oils can cause visible sheens, objectionable odours, and alter the taste of water, impacting recreational use and public perception.

How Refined Oil Sensors work

Many refined petroleum products contain aromatic hydrocarbons that fluoresce when exposed to UV light wavelengths. The sensor operates by emitting a specific ultraviolet wavelength of light (e.g., around 254nm or 275nm), into the water sample. This particular light excites the Hydrocarbons found in refined oil products. The excited hydrocarbon molecules then fluoresce, re-emitting light at a distinct, longer wavelength (e.g.,340nm to 400nm). A sensitive detector precisely measures the intensity of this emitted fluorescence, with the intensity being directly proportional to the amount of hydrocarbons present, thereby providing a real-time measurement of refined oils present.

The Aquaread Refined Oil sensor, for use with the AP-6000 or AP-7000 probe, use an excitation at 285nm and then detects the resultant fluorescence between 330nm and 370nm. This sensor emits high intensity ultraviolet (UV) light, which is harmful to skin and eyes.

When to use the sensor

Refined oil monitoring is an essential practice for protecting water quality and ecosystems, particularly in areas susceptible to petroleum contamination. It is highly valuable for:

• Industrial Outfalls: Regularly monitoring discharges from industrial facilities, refineries, and chemical plants to ensure compliance with effluent limits.
• Storm water Runoff: Assessing runoff from urban areas, roads, and industrial sites where oil and fuel residues can accumulate and be washed into waterways.
• Harbours and Marinas: Continuous monitoring in ports, docks, and boating areas to detect spills from vessels or shore-based activities.
• Construction Sites: Monitoring water bodies adjacent to construction where heavy machinery is used, increasing the risk of fuel and oil leaks.
• Groundwater Monitoring Wells: Detecting contamination in groundwater near fuel storage tanks, pipelines, or industrial sites.
• Environmental Spill Response: Providing rapid assessment of oil presence and concentration during and after spill events to guide containment and cleanup operations.
• Source Water Protection: Safeguarding drinking water intakes from potential contamination by petroleum products.
• Pipeline and Storage Tank Integrity Monitoring: As part of a larger monitoring program to detect leaks from buried infrastructure.

7000-REFOIL Electrode

The 7000-REFOIL electrode is a Refined Oil sensor designed for the detection of processed hydrocarbons in Fresh Water and connection with the AP-6000 or AP-7000 water quality probe from Aquaread. It is designed to give a measure of refined oil in fresh water. It achieves this by emitting light into the sample and measuring the Fluoresce light re-emitted by hydrocarbons in the sample. This fluorescence measurement techniques is not ideal for quantitative measurements, but can be used to get an indication of increasing or decreasing concentrations over time at a given location.

Automatic Cleaning Mechanisms on AquaProbe

Both the AP-6000 and AP-7000 AquaProbes include automatic cleaning mechanisms which are incredibly beneficial for any optical sensor. The brush and wipers are critical because they:

• Prevent Biofouling Build-up: By periodically wiping the optical surfaces, they physically remove algae, biofilm, and other organic matter before it can significantly impact readings. This is especially crucial for long-term deployments.
• Dislodge Air Bubbles: The wiping action effectively dislodges any trapped air bubbles that might cling to the sensor’s surface, ensuring a clear path for light transmission and reception. Air bubbles are a common issue in turbulent waters or when probes are initially deployed.
• Maintain Accuracy: By keeping the optical windows clean, the cleaning mechanism ensures the sensor’s readings remain accurate and reliable over extended periods, reducing the need for frequent manual cleaning and site visits.