Are you curious about how the water quality of rivers and lakes impacts daily life? With the upgrading of environmental protection regulations, surface water monitoring has become a key tool for assessing ecological health. The conventional five parameters—water temperature, pH, dissolved oxygen (DO), conductivity, and turbidity—are the foundation for detecting water pollution, quickly revealing pollution sources and change trends. According to the latest specifications from the Ministry of Ecology and Environment, the monitoring methods for these parameters have been optimized to support automation and real-time analysis. If you are an environmental engineer, researcher, or water enterprise executive, mastering these national standards can help you improve monitoring accuracy and avoid compliance issues. This article is problem-oriented, structured to present professional content, providing cases and real scenarios to ensure a smooth and reliable reading experience.
The conventional five parameters originate from the "Surface Water Environmental Quality Standards" (GB 3838-2002) and related technical specifications, serving as the core parameters of the national water quality automatic monitoring system. These parameters are commonly used for daily evaluation and emergency response:
- Water Temperature: Affects dissolved oxygen and biological activity; abnormal increases may indicate industrial thermal pollution.
- pH: Measures acidity and alkalinity; deviations from 7 may cause fish deaths or pipeline corrosion.
- Dissolved Oxygen (DO): Reflects the self-purification capacity of water bodies; low values suggest organic pollution or eutrophication.
- Conductivity： Indicates ion concentration; high values may originate from salinization or sewage discharge.
- Turbidity: Measures suspended matter content; high turbidity affects photosynthesis and drinking water safety.
Abnormalities in these parameters often signal ecological crises. The 2024 Ministry of Ecology and Environment report shows that many rivers nationwide have been affected in aquatic biodiversity due to exceeding turbidity and dissolved oxygen limits. Question: How to accurately monitor these parameters? The latest national standards provide standardized paths to ensure data credibility.
The latest specifications refer to the "Technical Specifications for Surface Water Environmental Quality Monitoring" (HJ 91.2-2022), emphasizing on-site in-situ measurement, quality control, and instrument calibration. The following table summarizes the latest method standards, applicable ranges, and operational points for each parameter (based on standards effective in 2025):
Parameter | Latest National Standard Code | Monitoring Method | Operational Points and Applicable Range |
Water Temperature | HJ 91.2-2022 | Temperature sensor or mercury thermometer method | On-site in-situ measurement, range 0-50℃; applicable to all water bodies, avoid direct sunlight. |
pH | HJ 1147-2020 | Glass electrode method | On-site probe measurement, range 2-12; applicable to rivers and lakes, calibrate electrodes regularly. |
Dissolved Oxygen (DO) | HJ 506-2009 | Electrochemical probe method or fluorescence method | On-site measurement with temperature compensation; applicable for DO >0.1mg/L, avoid bubble interference. |
Conductivity | HJ 802-2016 | Electrode method | On-site measurement, range 0-2000μS/cm; applicable for assessing salinity and pollution. |
Turbidity | HJ 1075-2019 | Scattered light method | On-site or laboratory measurement, range 0-400NTU; applicable for suspended matter monitoring, shake samples evenly. |
These methods support portable device applications, with sampling following HJ 91.2-2022: select representative points, avoid interference sources, and have at least 2 parallel samples. Question: Is your equipment compatible with these standards? If not, the data may be questioned.
Taking a river basin in Shanxi as an example, in 2023, the river showed abnormalities in turbidity and dissolved oxygen. The monitoring team used HJ 1075-2019 and HJ 506-2009 methods, finding turbidity reaching 150NTU (exceeding the limit by 3 times), tracing it to upstream mining discharges. After treatment, through continuous monitoring, the parameters returned to normal, and fish populations increased by 30%. Endorsement: The Ministry of Ecology and Environment guidelines emphasize that such methods have an accuracy rate exceeding 90% in pollution source tracing, supporting water quality improvement in the "14th Five-Year Plan." Real scenario: In Chongqing's "Bayu Water Control" project, real-time monitoring of the five parameters warned of anomalies, improving disposal efficiency by 80% and preventing large-scale pollution spread.
In drinking water source protection, these standards are applied to industrial park discharge supervision. For example, factories in the Pearl River Basin need to monitor conductivity and turbidity weekly, with exceedances potentially triggering fines. Question: How to implement efficiently? Recommend integrated equipment, such as the portable multi-parameter water quality detector ERUN-SP9. It supports real-time detection of water temperature, pH, DO, conductivity, and turbidity, complying with HJ standards, with laboratory-level precision. For details, visit: [ERUN-SP9 Product Page](https://www.erunwqs.com/products-detail/id-458.html). A water engineer shared: "In field inspections, ERUN-SP9 simplifies operations, with automatic data upload, improving response speed by 40%." This is based on actual feedback, aiding seamless integration from monitoring to governance.
Understanding the latest national standards is the starting point for improving water quality management. Whether for daily patrols or pollution responses, these methods ensure professionalism and reliability. It is recommended to refer to official resources and select compliant equipment. Tools like ERUN-SP9 can optimize your processes.
