How to test the water quality and where to test the water quality

When choosing a water quality detector, you need to consider the following key factors: 1Detection parameters:

Based on your specific needs, determine the water quality parameters that need to be tested, such as: pH, dissolved oxygen, turbidity, total organic carbon, ammonia nitrogen, etc. 2.

Accuracy and stability: Accuracy and stability are important indicators to measure the performance of water quality detectors. A high-precision detector can more accurately reflect the water quality situation, while a stable detector can ensure the accuracy of long-term use.

3.Operability and maintenance: The easy-to-operate and maintainable water quality detector can reduce the burden on users and improve work efficiency.

4.Brand and **: Well-known brands usually have better product quality and technical support, while reasonable ** can guarantee cost performance.

It should be noted that when choosing a water quality detector, the selection ,... should be combined with actual needs

Residual Chlorine Detection Method:

Colorimetry: In response to the worsening water pollution problem, the waterworks adopt the method of adding a large amount of chlorine (bleaching powder) that exceeds the standard to disinfect and sterilize. Although chlorination can kill various germs in the water, once it is combined with the organic matter in the water, it will produce a large amount of organic chloride (such as chloroform, dibromochloromethane) due to the effect of residual chlorine or bleaching powder, which is harmful to human health.

Organochlorides have been identified as carcinogens in animal tests.

Most people think that simply boiling tap water can kill bacteria, but in fact, boiling water for 20 minutes is enough to remove harmful bacteria or viruses. During the boiling process, chlorine in the water will intensify the combination with organic matter, resulting in the formation of a large number of carcinogens such as trihalomethanes, especially in the period of 100. To remove chlorine, it is necessary to boil for more than 30 minutes and open the lid of the pot to allow the chlorine to evaporate with the steam.

Otherwise, the trihalomethanes synthesized from chlorine will remain in the water and pose a chronic health hazard.

TDS pen: The conductivity of water has a certain relationship with the amount of inorganic acid, alkali and salt it contains. When their concentration is low, the conductivity increases with increasing concentration, so this metric is often used to estimate the total concentration or salt content of ions in water.

Different types of water have different electrical conductivity. The conductivity of freshly distilled water is 2—4 s cm due to the absorption of CO2 after a period of time. The conductivity of ultrapure water is less than; The conductivity of natural water is mostly between 50 and 500 s cm, and the conductivity of mineralized water can reach 500 to 1000 s cm. The conductivity of industrial wastewater containing acids, alkalis and salts often exceeds 10 000 s cm; The electrical conductivity of seawater is about 30 000 s cm. Conductivity is an important indicator of the purity of pure water, reflecting the purity of pure water and the control of the production process.

The national standard stipulates that the electrical conductivity in purified water shall not be higher than 10 s cm.

To test the water quality, you can choose the local water affairs bureau, health supervision institute and health and epidemic prevention station (also known as the CDC) and other departments to carry out relevant drinking water quality testing, in addition, you can also entrust a third-party authoritative environmental testing company with CMA qualification to conduct relevant water quality testing. <

To test the water quality, you can choose the local water affairs bureau, health supervision institute and health and epidemic prevention station (also known as the CDC) and other departments to carry out relevant drinking water quality testing, in addition, you can also entrust a third-party authoritative environmental testing company with CMA qualification to conduct relevant water quality testing.

Is it to test commonly used water or wastewater, you can go to some institutions that do water quality testing.

Methods for testing water quality include direct observation, TDS water quality testing pens and professional testing.

1. Direct observation.

The simplest and roughest method of water quality testing is to fill a representative water with a measuring cup or a glass cup with high transparency, and observe whether it contains fine impurities and floating objects in the light. After the water is allowed to stand for three hours, observe with the naked eye whether there is sediment and whether the color of the water is abnormal, if there is, it means that the suspended impurities in the water are seriously exceeded.

2. TDS water quality testing pen.

It can carry out simple self-test on water hardness and water-soluble matter, and TDS water quality testing pen is a popular water quality self-test tool in recent years. The lower the TDS value is displayed when the TDS pen is placed in the water to be tested, the less dissolved solids there are in the water and the purer the water quality. According to the "Drinking Water Standard", the TDS value is less than 1000mg L for qualified water quality.

3. Professional testing.

Professionals use testing instruments to conduct a comprehensive analysis of water quality data. When the amount of water we need to test is relatively large, or when it has a significant impact on people's health. You can contact professional water quality testing agency personnel to use ultra-high-precision water quality testing instruments to conduct on-site testing of water quality.

Water quality testing indicators

1. Total solids: the total amount of solid matter remaining after evaporation and drying of water samples at 103-105, also known as evaporation residues.

2. Suspended solids and dissolved solids: After the water sample is filtered, the residual solids after the filter sample intercept is evaporated and the residual solids are called suspended solids, and the residual solids of the locust after the filtrate is evaporated.

3. Volatile solids and stationary solids: the weight lost by burning the solid after evaporation and drying in the water sample at a certain temperature (600), which can be roughly expressed as the organic matter content. The weight of the residual material after burning is called a stationary solid.

4. Conductivity: Conductivity refers to the conductivity of a certain volume of solution, that is, the conductivity of the solution between two plate electrodes with an area of 1 square centimeter and a spacing of 1 cm at 25.

5. Non-specific indicators: conductivity, pH value, hardness, alkalinity, inorganic acidity, etc.

6. Non-specific organic matter index: total oxygen consumption, chemical oxygen consumption, biochemical oxygen consumption, total organic carbon, potassium permanganate index, phenols, etc.

1. Look. Fill a glass of water with a glass with high transparency, look at the light to see if there are any fine substances suspended in the water, let it stand for three hours, and then observe whether there is sediment at the bottom of the cup.

2. Smell. Use a glass as far away from the faucet as possible to pick up a glass of water, and then smell it with your nose, is it a reflection of the smell of bleaching powder (chlorine)? If you can smell the smell of bleaching powder (chlorine), it means that the residual chlorine in the tap water exceeds the standard.

3. Taste. If you can smell the smell of bleaching powder (chlorine), it means that the residual chlorine in the tap water exceeds the standard, and you must also use a water purifier for terminal treatment.

4. View. Make tea with tap water, observe whether the tea turns black after overnight, if the tea turns black, it means that the iron and manganese content in the tap water is seriously exceeded, and a water purifier equipped with iron removal and manganese filter elements should be used for terminal treatment.

5. Product. Taste boiled water, there is no astringent feeling in the taste, if there is, it means that the hardness of the water is too high.

6. Check. Check the water heater and boiling kettle at home, whether there is a layer of yellow scale on the inner wall, if there is, it also means that the hardness of the water is too high, (calcium and magnesium salt content is too high), and softening treatment should be used as soon as possible.

Install the water body that needs to be detected with an object, take out the detector model knower, and test it according to the steps of each instrument according to the use of the year, some instruments and meters need to be calibrated before measurement, and you can operate according to the instructions you can buy instruments and meters.

Look: Fill a glass of water with a glass with high transparency, look at the light to see if there are any fine substances suspended in the water, let it stand for three hours, and then observe whether there is sediment at the bottom of the cup, if there is, it means that the suspended impurities in the water are seriously exceeded. Smell:

Use a glass to get a glass as far away from the tap as possible, and then smell it with your nose to see if there is a smell of bleaching powder (chlorine). Taste: Boil the water, drink it after cooling, taste whether there is the taste of bleaching powder (chlorine), if you can smell the taste of Zheng Ying's bleaching powder (chlorine), it means that the residual chlorine in the tap water exceeds the standard.

1. Look: Fill a glass of water with a glass with high transparency, look at the light to see if there are any fine substances suspended in the water, let it stand for three hours, and then observe whether there is sediment at the bottom of the cup.

2. Smell: Use a glass to get a glass of water as far away from the faucet as possible, and then smell it with your nose, is there a smell of bleaching powder (chlorine)? If you can smell the smell of bleaching powder (chlorine), it means that the residual chlorine in the tap water exceeds the standard.

3. Taste: Boil the water, drink it after cooling, taste whether there is the taste of bleaching powder (chlorine), if you can smell the taste of bleaching powder (chlorine), it means that the residual chlorine in the tap water exceeds the standard.

4. Observation: Make tea with tap water, observe whether the tea turns black after overnight, if the tea turns black, it means that the iron and manganese in the tap water are seriously exceeded, and the water purifier equipped with iron removal and manganese filter element should be used for terminal treatment.

5. Taste: Taste boiled water, accompany the taste of whether there is a feeling of astringency, if there is, it means that the hardness of the water is too high.