1、 Technical principle: How does oil pollution "manifest"?

The core of detecting oil pollution in water lies in utilizing the physical and chemical properties of oil molecules. The conjugated double bonds in oil molecules have characteristic absorption peaks in the ultraviolet region (200-400nm). When the sample is irradiated with ultraviolet light, the oil molecules absorb light of a specific wavelength, resulting in a decrease in light intensity (i.e. "absorbance"). By measuring the absorbance and combining it with the standard curve, the oil concentration can be calculated.

In addition, infrared spectrophotometry utilizes the vibrational absorption characteristics of CH ₂ and CH Ⅲ groups in oil molecules at specific infrared wavelengths to convert oil concentration by measuring absorbance; The UV fluorescence method is based on the proportional relationship between the intensity and concentration of fluorescence released by oil molecules after being excited by ultraviolet light, achieving automated detection.

2、 Testing Method: "Technical Matrix" from Laboratory to Site

There are various methods for detecting oil content in water, and you can choose according to your needs:

UV spectrophotometry

Principle: Utilize the absorption characteristics of oil molecules towards ultraviolet light.

Advantages: Easy to operate, high sensitivity (able to measure 0.01mg/L), strong anti-interference (not affected by water color or suspended solids).

Process: Extract oil from water sample → Dehydrate and remove impurities → Adsorb animal and vegetable oil with magnesium silicate → Measure absorbance → Convert concentration.

Application: Laboratory routine testing, environmental monitoring station.

Infrared spectrophotometry

Principle: Based on the infrared absorption characteristics of CH ₂ and CH ∝ groups in oil molecules.

Advantages: High sensitivity, good separation effect, able to distinguish mineral oil from animal and vegetable oil.

Process: Extract oil → Measure absorbance using an infrared spectrometer → Convert concentration.

Application: Petrochemical wastewater treatment, marine oil pollution monitoring.

UV fluorescence method

Principle: Oil molecules release fluorescence when excited by ultraviolet light, and the fluorescence intensity is proportional to the concentration.

Advantages: High degree of automation and reduced human error.

Process: Water sample pretreatment → Fluorescence sensor measurement → Data output.

Application: Online monitoring system, emergency accident handling.

Other methods

Weight method: Traditional method for calculating oil content through extraction, evaporation, and weighing, suitable for standard setting.

Chromatography: Separation of mixtures using the difference in distribution coefficients of substances in the stationary and mobile phases, with high sensitivity but complex operation.

Electrochemical method: calculates concentration by measuring changes in current and voltage between oil and electrodes, suitable for rapid on-site detection.

3、 Application scenario: "Full coverage" from water sources to industrial circulating water

The detection of oil content in water is widely used in the following fields:

environmental monitoring

Surface water monitoring: detecting oil spills and pollution in rivers and lakes, and locating pollution sources.

Groundwater assessment: Investigate the risk of oil contamination infiltration in groundwater around gas stations and chemical plants.

Industrial wastewater treatment

Petrochemical industry: Monitor the wastewater treatment efficiency of refineries and chemical plants to ensure that the oil concentration is ≤ 10mg/L (first level standard).

Catering industry: Detect the effluent from restaurant oil separators to prevent excessive discharge of animal and vegetable oils.

Ocean and Ship Monitoring

Offshore waters: Monitor the spread range of crude oil spills and assess ecological impacts.

Ship ballast water: Check whether the oil content meets the International Maritime Organization (IMO) standards.

4、 Equipment selection: From portable to online monitoring "toolbox"

According to the testing requirements, the following devices can be selected:

Laboratory desktop equipment

UV spectrophotometer oil analyzer: suitable for high-precision detection.

Infrared spectrophotometer: can distinguish mineral oil from animal and vegetable oil.

portable device

Handheld water quality analyzer: supports multi parameter detection and is suitable for rapid on-site screening.

Online monitoring system

UV fluorescence online monitor: can monitor the oil concentration at industrial circulating water and sewage discharge outlets in real time.

Infrared online monitoring device: suitable for batch detection of large water bodies.

5、 Future trend: Intelligent and portable "dual wheel drive"

With the development of technology, the detection of oil content in water is upgrading in the following directions:

Intelligent detection: integrates automatic sampling, data processing, and report generation functions to achieve "one click detection".

Portable design: Develop handheld instruments that support rapid on-site detection (such as emergency response).

Multi parameter combination: Combining sensors such as pH and conductivity to achieve comprehensive evaluation of water quality.

Conclusion

The detection of oil content in water is the "first line of defense" for safeguarding water ecological security. From the UV spectrophotometer in the laboratory to portable devices on site, from environmental monitoring to industrial control, technology constantly iterates to safeguard water quality safety. Whether it is environmental protection departments, industrial enterprises, or scientific research institutions, choosing appropriate detection methods and equipment is necessary to accurately reveal the "hidden truth" of oil pollution in water and protect green mountains and clear waters.