The total organic carbon content (TOC) is one of the most important water quality parameters and measures the amount of organic pollutants in the water. It is used in various industries such as water treatment, the pharmaceutical industry, food processing, the oil and gas industry, and semiconductor manufacturing. The TOC analyzer is an advanced instrument that accurately and quickly determines the organic carbon content of water and other liquid samples.
In this article, we deal with the functioning of TOC analyzers, the various TOC measurement methods, their applications in different industries, and the advantages of using these devices .
1. What is an obsessive-compulsive disorder and why is it important to measure it?
Total Organic Carbon (TOC) is the sum of all organic carbon compounds present in water, including naturally occurring organic substances (NOM), industrial pollutants, microorganisms, and by-products of chemical processes. Measuring TOC is important for the following reasons:
Monitoring Water Quality : In the pharmaceutical and food industries, water with a high content of organic carbon (TOC) can contaminate products.
Monitoring Organic Contaminants : In wastewater and drinking water treatment systems, TOC is an indicator of the level of contamination.
Optimizing Industrial Processes : In cooling systems and boilers, high TOC levels can cause corrosion and deposits.
Compliance with Environmental Regulations : Organizations such as the US Environmental Protection Agency (EPA) and the World Health Organization (WHO) have established maximum permissible TOC levels in water .
2. Types of TOC measurement methods
Analyzers for organic carbon use various methods to measure organic carbon, which can be divided into two main categories:
a) Combustion method
In this method, a water sample is burned at high temperatures (approximately 680 to 1200 degrees Celsius) to convert organic carbon into carbon dioxide which is then measured. The amount of the resulting carbon dioxide is subsequently measured with a non-dispersive infrared sensor (NDIR).
Advantages :
-
Very high resolution
-
Possibility to measure all organic compounds, including oxidation-resistant ones.
Disadvantages : -
High device costs
-
Requires more maintenance
b) Chemical oxidation process (wet chemical oxidation process)
< u0 >This method uses a strong oxidizing agent (e.g., potassium persulfate) to convert organic carbon into carbon dioxide under the influence of< /u0 >< u1 >< u7 >potassium persulfate< /u7 >< /u1 >< u2 >< u8 >ultraviolet light< /u8 >< /u2 > < /u3 > . < /u3 >< u4 >< u9 >Advantages< /u9 > : < /u4 >< q5 > < /q5 > < q6 > < /q6 >
-
Lower costs than combustion method
-
Suitable for samples with low TOC content.
Disadvantages : -
Some complex organic compounds may not be fully oxidized.
c) Differential method (NPOC or TC-IC)
In this method, first total carbon (TC) and then inorganic carbon (IC) are measured . The difference between the two values results in total organic carbon (TOC).
The calculation formula is as follows:
TOS = TS – IR TOS TS IR
3. Main components of the TOC analyzer
{A TOC analyzer typically consists of the following components=null}
-
{Water sample syringe =Injects a water sample into the device.}
-
Acid solution (removes inorganic carbon) : removes carbon dioxide from carbonates and bicarbonates.
-
Oxidation Chamber : converts organic carbon into carbon dioxide.
-
Carbon Dioxide Sensor (NDIR Detector) : measures the amount of emitted carbon dioxide.
-
Data Processor : analyzes and displays results.
4. Application of TOC analyzers in various industries
a) Pharmaceutical industry (Water for Injection – WFI)
-
The water used for the production of intravenous drugs must have a very low total organic carbon content (less than 500 ppb).
-
The TOC analyzer monitors the water quality online.
b) Food and Beverage Industry
-
In mineral water and beverage production, high levels of organic carbon may indicate microbial contamination.
c) Water and Wastewater Treatment
-
Monitoring of drinking water quality (based on the standards of the Environmental Protection Agency).
-
Explore the effectiveness of cleaning systems such as reverse osmosis (RO) and ultraviolet light.
d) Oil, Gas, and Petrochemical Industry
-
Measurement of total organic carbon in industrial wastewater for compliance with environmental regulations.
5. Advantages of Using a TOC Analyzer
-
High speed : Results in less than 5 minutes.
-
Excellent accuracy : Measurement capability up to the ppb range (parts per billion) .
-
Reduction of laboratory test costs: Replacement of traditional methods such as biochemical and chemical bioassays.
-
Online monitoring : Can be installed for continuous monitoring on the production line.
6. Comparison of TOC and other water quality indicators (biochemical oxygen demand, physicochemical demand)
| Range | Table of Contents | biochemical oxygen demand | chemical oxygen demand |
|---|---|---|---|
| Mess speed | How many minutes? | 5 days | Two hours |
| Accuracy | very large | Half | higher |
| Allergy to toxic substances | A little | many | Half |
| Main application areas | Water quality monitoring | Wastewater monitoring | Chemical industry |
7. Conclusion
TOC analyzers (Total Organic Carbon) are indispensable tools for the accurate and rapid measurement of organic carbon in water and play a key role in water quality monitoring, pollutant control, and the optimization of industrial processes. Technological advances have led to the development of portable, internet-enabled TOC analyzers, which enable continuous water quality monitoring.