How to cultivate activated sludge in a laboratory

The cultivation of activated sludge in the laboratory can generally be divided into two types: static cultivation and dynamic cultivation. 1. Static cultivation: Usually, sludge from kitchen sewers is used; some wastewater and nutrients are added in specific proportions, and aeration is carried out using the aerator used for raising goldfish at home. The water is then changed regularly. It is also possible to use the nitrification and dewatering sludge from municipal wastewater treatment plants, adding it at a ratio of 3%–5% to the culture container; then add about 40% wastewater, incorporate nutrients, and proceed with aeration. 2. Dynamic cultivation: Fill a large container (with a volume more than 20 times that of the container used for culturing sludge) with sewage, and connect an IV tube, similar to those used in hospitals for intravenous infusions, to this container (note: there should be a difference in water level between the large container and the culturing container, and a container should be placed beneath the culturing container to collect any excess wastewater). Sludge from kitchen drains or nitrifying sludge from sewage treatment plants can be used for cultivation; nutrients should be added regularly, and aeration can be achieved using an oxygenator used for raising goldfish at home. Either of the two cultivation methods is acceptable, but it is important to add the wastewater that needs to be treated in order to acclimate the sludge; otherwise, the cultivated sludge may not be suitable for treating actual wastewater, and in that case it has little practical value. At the same time, during the cultivation process, it is essential to pay close attention to observations, and the amount of wastewater used should be increased gradually; it is not possible to use 100% raw wastewater, as some of this wastewater contains many toxic and harmful substances. Such wastewater must first undergo physical and chemical treatment before being fed into the biochemical system. If the raw water is highly toxic, it is recommended to carry out necessary physical and chemical treatments in accordance with the process design concepts, and then use the treated water for sludge cultivation. This not only allows for testing the feasibility of the physical and chemical treatment approach but also ensures the success of biochemical cultivation.

Thank you so much. In our laboratory, when culturing sludge, it’s difficult to find domestic wastewater; we use tap water instead, and we add potassium dihydrogen phosphate, urea, and glucose artificially, but the results are not good. Last edited by Inert Gas 8 on 2009-4-16 at 14:29.]