Safe drinking water is essential for human health, preventing waterborne diseases and ensuring water is palatable and free from harmful contaminants. Regular testing of parameters such as Chemical Oxygen Demand (COD), pH, and temperature is critical to assess water quality and comply with international and national standards, such as the World Health Organization’s (WHO) Guidelines for Drinking-Water Quality and China’s GB 5749-2022. This article explores these key parameters, their significance, measurement methods, and the role of advanced detectors like the ERUN-SP9 in ensuring water safety. Through case studies and real-world applications, we highlight how such tools empower municipalities, industries, and communities to maintain high-quality drinking water.
Drinking water quality is evaluated through physical, chemical, and biological parameters. Below are the primary ones relevant to this discussion:
Definition: COD measures the oxygen required to chemically oxidize organic and inorganic matter in water, expressed in milligrams per liter (mg/L). It’s a key indicator of organic pollution.
Significance: High COD levels suggest organic contaminants, which can deplete dissolved oxygen and compromise water safety. For drinking water, COD is expected to be very low, typically below 5 mg/L, though the WHO does not specify a direct COD limit. China’s GB 5749-2022 references organic parameters under GB/T 5750.7-2006, with research suggesting COD levels below 4–5 mg/L for safe drinking water.
Measurement: COD is measured using a chemical test where water samples are oxidized with potassium dichromate under acidic conditions, followed by spectrophotometric analysis.
Definition: pH measures water’s acidity or alkalinity on a scale from 0 to 14, with 7 being neutral.
Significance: The WHO and U.S. Environmental Protection Agency (EPA) recommend a pH range of 6.5–8.5 for drinking water. A pH below 6.5 can corrode pipes, leaching metals like lead or copper, posing health risks. A pH above 8.5 may cause scaling, affect taste, and reduce disinfection efficacy. Proper pH ensures water is safe and palatable.
Measurement: pH is measured using pH meters with electrodes or test strips, with modern detectors offering precise, real-time readings.
Definition: Temperature reflects the thermal state of water, measured in degrees Celsius (°C).
Significance: While not directly regulated for health, temperature affects palatability, chemical reactions, and microbial growth. A range of 10–25°C is considered comfortable for drinking water. Higher temperatures may promote pathogen growth, while lower ones can slow disinfection processes.
Measurement: Temperature is measured using thermometers or integrated sensors in water quality detectors.
Beyond COD, pH, and temperature, other parameters are vital for comprehensive water quality assessment:
Turbidity: Measures water clarity, with levels below 1 NTU indicating minimal suspended particles that could harbor pathogens.
Total Dissolved Solids (TDS): Represents dissolved minerals and salts, with 50–150 mg/L typically acceptable for taste and safety.
Microbiological Contaminants: Total coliforms and E. coli must be absent to ensure no fecal contamination.
Heavy Metals: Lead, arsenic, and mercury have strict limits (e.g., lead <0.01 mg/L per WHO) due to their toxicity.
The following table summarizes these parameters:
| Parameter | Description | Ideal Range | Significance |
|---|---|---|---|
| COD | Chemical Oxygen Demand | <5 mg/L | Indicates organic pollution |
| pH | Acidity/Alkalinity | 6.5–8.5 | Affects taste, pipe integrity, metal solubility |
| Temperature | Thermal state | 10–25°C | Influences palatability and microbial growth |
| Turbidity | Water clarity | <1 NTU | Indicates suspended particles |
| TDS | Total Dissolved Solids | 50–150 mg/L | Affects taste and mineral content |
| Microbiological | Total coliforms, E. coli | Absent | Ensures no fecal contamination |
| Heavy Metals | Lead, arsenic, mercury | Specific limits | Prevents health risks |
Drinking water quality is governed by rigorous standards to ensure safety:
WHO Guidelines for Drinking-Water Quality: Recommends pH of 6.5–8.5, absence of microbiological contaminants, and strict limits for heavy metals. WHO Guidelines
U.S. EPA National Primary Drinking Water Regulations: Enforces standards for over 90 contaminants, including pH (6.5–8.5) and heavy metals. EPA Regulations
China’s GB 5749-2022: Specifies requirements for drinking water, including pH (6.5–8.5), low organic content (indicative COD <5 mg/L), and microbiological safety. Code of China
These standards provide a framework for ensuring drinking water meets health and safety requirements globally.
Accurate and efficient water quality testing is crucial for compliance and public health. Multi-parameter detectors streamline this process by measuring multiple parameters simultaneously, reducing time and cost.
The ERUN-SP9 is a cutting-edge multi-parameter water quality detector designed for precision and versatility. Its features include:
Multi-Parameter Detection: Measures nearly 100 parameters, including COD (5–2000 mg/L), pH (0.00–14.00), temperature, turbidity, TDS, ammonia, total phosphorus, and total nitrogen, using electrode and spectrophotometric methods.
High-Efficiency Digestion: Dual-temperature zone system allows simultaneous testing of multiple samples.
Field-Ready Design: Dust-proof, water-proof, and collision-proof, with a 48-hour battery life, ideal for outdoor use.
Data Management: Stores up to 99,999 records, supports USB data export, and features a bilingual (Chinese/English) interface.
Customization: Parameters and ranges can be tailored to specific needs, with 200 pre-stored and 3000 user-defined curves.
User-Friendly Interface: Large color touch screen with built-in guides and authority management for secure operation.
The ERUN-SP9 is suitable for scientific research, sewage treatment, environmental monitoring, and enterprise self-inspection, particularly for testing drinking water, surface water, and groundwater.
In urban settings, water treatment plants require continuous monitoring to meet standards like GB 5749-2022. The ERUN-SP9’s real-time measurement of COD, pH, and other parameters enables operators to detect contamination quickly, ensuring safe water distribution to millions of residents.
In rural China, communities relying on wells face challenges with water quality. A village used the ERUN-SP9 to test well water, identifying low pH and elevated COD levels. Adjustments were made to neutralize acidity, preventing pipe corrosion and ensuring safe drinking water.
Following floods, rapid water quality assessment is critical to prevent waterborne diseases. The ERUN-SP9’s portability and long battery life allowed environmental agencies to test water sources on-site, ensuring safe drinking water during disaster recovery.
Industries near water bodies must monitor effluents to avoid contaminating drinking water sources. The ERUN-SP9’s multi-parameter capabilities help industries comply with environmental regulations, protecting downstream water quality.
Ensuring drinking water quality requires vigilant monitoring of parameters like COD, pH, and temperature, governed by standards such as WHO Guidelines and China’s GB 5749-2022. Advanced detectors like the ERUN-SP9 provide a reliable, efficient solution for water quality testing, supporting municipalities, industries, and communities in delivering safe drinking water. By investing in such technology, we can protect public health and promote sustainable water management globally.
