How should water samples from sewage treatment plants be stored? ? ?
Thread Content
The process of our company’s wastewater treatment plant is UASB-activated sludge. The range of test items is quite comprehensive, but when the water samples are stored (as mixed samples) directly in the refrigerator and tested the next day, what impact will biological degradation have on the test results? How do ordinary sewage treatment plants usually take samples only? Thank you! ! !
Please refer to Chapter 3, Sampling and Preservation of Water Samples, in Methods for the Monitoring and Analysis of Water and Wastewater (4th Edition). Specifically: 1. Storage requirements No physical, chemical, or biological changes shall occur ； Without losing components ； Do not contaminate (do not add components to be tested or interfering components). 2. Requirements for containers: Choose containers made of materials with stable properties, that do not easily adsorb the components to be analyzed and have low levels of impurities; for example, containers made of polyethylene and borosilicate glass are widely used in routine monitoring. Containers made of quartz or polytetrafluoroethylene can also be used, but they are more expensive. 3. Storage time requirement: That is, the maximum storage period; generally, the shorter the storage time for sewage, the better. Clean water sample 72h ； Slightly polluted water samples, 48 hours ； Severely polluted water sample for 12 hours ； Delivery time is within 24 hours. 4. Preservation methods (1) Refrigeration or freezing method (2) Preservation by adding chemical reagents: adding biological inhibitors, adjusting pH value, or adding oxidizing or reducing agents.
I’ve learned it... Thank you, seniors!