Sharing Four Methods for Reducing COD in Laboratory Wastewater Treatment

In the process of wastewater treatment, some rivers and lakes suffer from severe eutrophication due to phosphorus pollution. To control phosphorus pollution, the Environmental Protection Bureau has established strict standards for phosphorus emissions. The chemical-enhanced biological phosphorus removal process primarily focuses on removing organic pollutants and various forms of phosphorus from wastewater. This wastewater treatment process integrates chemical phosphorus removal and biological phosphorus removal. By producing volatile organic acids in the anaerobic digestion biological system through activated sludge, it serves as a substrate or nutrient for the growth of phosphorus-accumulating organisms (PAOs). This enables the selective proliferation of PAOs in the activated sludge, which is then recirculated into the biological system to maintain high-efficiency phosphorus removal. Simultaneously, the phosphorus released by the sludge under anaerobic conditions is eliminated through chemical phosphorus removal. As a high-tech environmental protection enterprise specializing in the R&D, production, sales, and technical service of professional laboratory wastewater treatment equipment, environmental water treatment, exhaust gas, and intelligent equipment, YexSensor explains several methods for reducing COD in wastewater treatment:

1. Chemical Coagulation Method

By adding flocculants, this method utilizes the adsorption bridging, double-layer compression, and net-sweeping effects of coagulants to destroy colloidal stability. This causes fine suspended solids and colloids to aggregate together to form precipitates, thereby achieving the effect of mud-water separation. It can effectively remove various high-molecular organic substances in the water. The equipment is simple, easy to maintain and operate, and the treatment effect is good; however, the operating costs are expensive, and the amount of sludge produced is large.

2. Electrochemical Method

This method involves chemical reactions occurring through a battery, utilizing the difference in metallic properties between the cathode and the anode to generate a potential difference. This causes a directional flow of electrons, generating an electric current. It utilizes the principle of electrolysis to remove pollutants from the water or convert toxic substances into non-toxic or less toxic substances. Currently, electrochemistry is widely applied in fields such as chemical industry, aviation, instrumentation, machinery, electronics, medicine, metal corrosion and protection, and environmental science.

3. O3 Oxidation Method

Ozone is an oxidizing agent that treats pollutants in wastewater through disinfection via the oxidant's oxidative properties. Because ozone has strong oxidizing ability, reacts rapidly, has a simple process, and has no secondary pollution issues, it is widely used in environmental protection and chemical directions. However, the electricity consumption for producing ozone is very high, leading to significant costs.

Technical Performance and Specifications (YEX-S1 Series)

FAQ Section

Q1: Why is pH monitoring mandatory in the COD degradation process?
Whether it is chemical coagulation or electrochemical methods, the reaction rate and effect are affected by pH. A deviation of pH from the optimal range will lead to a decrease in reagent utilization and directly trigger a rebound in COD readings.

Q2: What is the maintenance cycle for the YEX-S1-COD sensor?
Since the YEX-S1-COD utilizes UV absorption technology, it does not require chemical reagents. Maintenance is mainly limited to cleaning the optical window, typically every 1-3 months depending on the water quality.

Q3: How does the YEX-S1-RDO fluorescence method compare to traditional probes?
The YEX-S1-RDO does not consume oxygen during measurement and is not affected by flow rate or stirring. It does not require electrolyte replacement, making it ideal for low-maintenance industrial integration.

Q4: Can these sensors be integrated into existing PLC systems?
Yes. All YEX-S1 series sensors support the standard RS-485 Modbus RTU protocol, ensuring seamless compatibility with PLCs, DCS, and IoT gateways.

Q5: How does the YEX-S1-EC handle high salinity in laboratory waste?
The YEX-S1-EC is designed with high-grade electrodes and internal temperature compensation, allowing it to maintain accuracy even under fluctuating salinity conditions common in laboratory effluent.

Q6: Is secondary pollution a concern with ozone treatment?
Ozone treatment is known for being clean. However, integrators must ensure proper ozone tail-gas destruction units are in place to protect the laboratory environment.

Q7: What cable length is supported for RS-485 sensors?
The standard cable is 5 meters, but other lengths can be customized. RS-485 supports reliable data transmission up to 1200 meters, which is ideal for large laboratory facilities.

Q8: What protection level do these sensors offer for submersible use?
The YEX-S1-PH, YEX-S1-COD, and YEX-S1-RDO are all rated at IP68, meaning they are completely waterproof and suitable for long-term immersion in treatment tanks.

Summary

Effective COD reduction in laboratory wastewater requires a combination of scientific process combinations and precise monitoring feedback. For system integrators, choosing the YEX-S1 series from YexSensor—which offers high compatibility and digital advantages—is a core strategy to improve system delivery standards and reduce subsequent maintenance pressure. By deeply integrating processes such as chemical coagulation, electrochemistry, and ozone oxidation with RS-485 IoT technology, we can deliver truly closed-loop, efficient, and green wastewater treatment solutions to customers.