Introduction and Challenges

A Swiss based industrial company provides services to a chemical park, including residue treatment, power production and distribution, environmental protection and waste disposal, equipment maintenance, repair, and engineering automation. The chemical park is home to chemical manufacturers from different fields, with varying production efficiencies and processing requirements, making it challenging to provide them with services.

According to regulatory requirements, treating wastewater to protect soil, groundwater, and surface water from pollution is a challenging task. When the cooling water for public facilities and chemical processes is collected at the central location, operators must make the following decision: can the cooling water be directly sent into the river? Do we need a sewage treatment plant to treat it? Operators need to rely on real-time monitoring tools to make accurate judgments.

Various monitoring tools

The following parameters are commonly used in wastewater discharge permits:

Chemical Oxygen Demand (COD) - requires the use of hazardous chemicals and takes 2 hours to measure; or

Biochemical Oxygen Demand (BOD) - measurement takes 5 days.

TOC monitoring conveniently and quickly (less than 10 minutes) analyzes the overall organic content and organic removal rate by measuring the total amount of all organic carbon compounds.

TOC monitoring does not require the use of toxic chemicals, provides fast response time, and can capture all organic carbon compounds, making it the preferred method for organic matter monitoring. Many factories have begun to adopt TOC monitoring as the Best Available Technology (BAT) to continuously monitor the wastewater to be discharged into environmental waters. TOC monitoring is an economic and environmentally friendly technical method that can quantitatively capture large and growing organic pollutant groups.

Factories sometimes use UV-254 to measure organic content. Although UV-254 probes and displays are inexpensive, the probes can only recognize compounds containing 254nm wavelength chromophores, missing out on various other compounds including simple flat chain organic molecules. In addition, there is interference at the 254nm wavelength, including turbidity, nitrate, iron compounds, and other interferences. Due to the wide variety and variability of organic compounds collected in the chemical park, it is crucial to quickly and effectively measure the content of all carbon compounds. TOC analysis is a feasible method.

　　Solution using TOC analysis

Use three Sievers * online M9 TOC analyzers to analyze the mixed cooling water discharged by all companies in the chemical park (see Figure 1). To comply with the emission regulations of chemical industrial parks, the adequacy and reliability of measurement data are of utmost importance. If there is a significant change in the TOC of the mixed cooling water in the future, operators can use a specialized instrument to identify the source of pollution and more effectively eliminate it.

Sometimes the collected water flow contains sediment, clay, dirt, high hardness or high turbidity substances, making it difficult to accurately measure the organic matter content. But the M9 analyzer equipped with a Raw Water Sampler can prevent large particulate matter from interfering with TOC measurement. TOC refers to dissolved, gelatinous, and suspended particulate matter, excluding precipitable solids, inorganic precipitates, and organic particles. By using simple filtering methods to remove visible particles, the interference of solids on the measurement of organic compounds in water can be eliminated. The Sievers raw water sampler adopts an innovative design that utilizes gravity and laminar flow to remove pollutants from the TOC analyzer, enabling direct sampling from large particles and high turbidity water.

　　Conclusion

For the public facilities responsible for discharging cooling water on site, it is necessary to quickly decide whether to directly discharge the water into the environment or send it for treatment. But the composition of the water flow is constantly changing, depending on the manufacturer of the chemicals produced. Operators can use three TOC analyzers to monitor total organic carbon (TOC) in real-time, obtaining reliable, sufficient, and complete organic content data to make quick decisions and ensure compliance with regulations.

　　Reference materials

1. lb. Kompas / c/cimo-compagnieindustrielle-de-monthey-sa/ch 119795 /

2.Best Available Techniques(BAT)Reference Docu-ment for Common Waste water and Waste Gas Treatment/Management Systems in the Chemical Sector. Reference Document for Best Feasible Technologies for Common Wastewater and Waste Gas Treatment/Management Systems in the Chemical Industry

3. JRC Reference Report on Monitoring of Emissions from IED Installations. JRC Reference Report on Monitoring Emissions from IED Devices

4.EPA Method 415.3.Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water.EPA Method 415.3 Determination of total organic carbon and UV absorbance at 254 nm in source water and drinking water