What are the main items that need to be tested for domestic sewage?
Domestic sewage is the sewage produced in our daily life. The main content of sewage in life is organic matter and some pathogenic microorganisms. Because the organic matter in domestic sewage is extremely unstable, domestic sewage is easy to stink. Since sewage testing contains a large number of pathogens, direct discharge is likely to produce some infectious disease viruses, which endanger human health. Therefore, domestic sewage must pass the test before it can be discharged. What are the domestic sewage testing items? Domestic sewage testing items 1. Chemical oxygen demand High chemical oxygen demand means that the water contains a large amount of reducing substances, mainly Organic Pollutants. The higher the chemical oxygen demand, the more serious the organic matter pollution of the river water is. 2. The aerobic microorganisms in the biochemical oxygen demand water decompose the organic matter in the water into inorganic matter at a certain temperature. The amount of dissolved oxygen is a comprehensive indicator of the content of aerobic pollutants such as organic matter in water. 3. Suspended solid matter suspended in water, including insoluble inorganic matter, organic matter and mud sand, clay, microorganisms, etc. The content of suspended solids in water is one of the indicators to measure the degree of water pollution. 4. The total number of bacteria refers to the total number of bacterial colonies grown in the nutrient agar medium of ml water sample after 24 hours of cultivation at 37 degrees Celsius. 5. After the total phosphorus water sample is digested, various forms of phosphorus are converted into orthophosphate The results of the determination are measured in milligrams of phosphorus per liter of water sample. 6. Coliform bacteria refer to a group of bacteria related to feces pollution with certain characteristics. These bacteria are not completely consistent in biochemistry and serology. The definition It is: aerobic and facultative anaerobic Gram-negative bacteria that can decompose lactose to produce acid and gas at 37°C. 7. Ph value pH is a scale of hydrogen ion activity in a solution, which is a measure of the acidity and alkalinity of a solution in the usual sense. 8. Ammonia nitrogen refers to nitrogen existing in the form of free ammonia (NH3) and ammonium ions (NH4) in water. The nitrogen content of animal organic matter is generally higher than that of vegetable organic matter. At the same time, nitrogen-containing organic matter in human and animal manure is very unstable and easily decomposed into ammonia. Therefore, when the content of ammonia nitrogen in water increases, it refers to the combined ammonia existing in the form of ammonia or ammonium ions. Ammonia nitrogen mainly comes from human and animal excrement, and the average nitrogen content in domestic sewage can reach 2.5-4.5 kg per person per year. 9. Phosphate Phosphate is one of the natural components of almost all foods, and is widely used in food processing as an important food ingredient and functional additive. Phosphate is a major component of total dissolved solids, a major water quality indicator, under pollution concerns. The above are the routine testing items of domestic sewage, and the specific cost of domestic sewage testing depends on the testing items.