Today, the most frequently established type of residential wastewater treatment plant is the activation treatment plant. In the second part of the series, we will look at how to prepare it for winter
Preparation for the winter at the activated wastewater treatment plant could be summed up in a few words.
Vyčistit
Just as you clean, paint and clean your garden furniture before winter, treat the treatment plants with the same care. Since you usually have to drain the utility water hoses and pipes during the winter, you won't be able to shower your pet regularly. So give it a thorough cleaning before winter, otherwise you won't be able to get rid of sludge deposits.
Odkalit
A large part of the owners of household treatment plants dispose of excess sludge by composting in the garden. However, composting is quite problematic during the winter, so it is advisable to remove the sludge for the last time at the beginning of the winter and then in the spring.
Another part of treatment plant owners have the excess sludge taken away by a sewage truck. In winter, due to snow and frost, access to the wastewater treatment plant is worse, so even in this case it is better to clear the sludge before winter.
How much? If your wastewater treatment plant is not overloaded (i.e., for example, sewage from five people flows into the wastewater treatment plant for 5 EO), the volume of sludge (of good quality!) after 30 minutes of sedimentation will be 250-350 ml/l. If the treatment plant is overloaded (but manages to remove pollution during the summer), leave the amount of sludge slightly higher.
Reducing the amount of sludge in the system will also reduce the formation of foams and sludge blankets in the activation and settling tanks. Fortunately, you won't find these formations at every treatment plant, but when they are there, they like to change their state to solid in the cold. The resulting ice shards can then damage your treatment plant. If you still can't remove the foam, watch to see if it starts to freeze. If so, aerate the treatment plant for a shorter period of time and more often, this will mix the foam more.
CAUTION! If your treatment plant has to remove ammoniacal nitrogen, the situation is diametrically different. Nitrifying bacteria work slowly in the cold and grow poorly, so it is good to keep a lot of sludge in the treatment plant in winter. The minimum is roughly 500 ml/l, the maximum is when the sludge does not flow out of the settling tank when draining the bath or during other sudden discharges (at least 900 ml/l).
Izolovat
I must point out that a treatment plant that has an inflow at a non-freezing depth is a few meters from the source of wastewater and there are not exactly record long-lasting frosts, so you do not need to thermally insulate such a treatment plant. If you use it all winter, there is no risk of freezing. In the event that it freezes really hard, it is not out of the question to make additional insulation. The main thing to cover is the hatch or other covering of the treatment plant. You can use anything, polystyrene boards, bales of straw, a pile of hay, a pile of snow... There are no limits to your imagination. It is important that the material does not fall inside the treatment plant, that the insulation can be easily removed (after all, you will check the treatment plant in winter, and if it freezes, all the more often) and that it really insulates. One more note - the cover must not be airtight. You blow air into the treatment plant and it, slightly depleted of oxygen and slightly enriched with carbon dioxide, has to go out somewhere.
While we're on the subject of insulation, don't forget to check the fit of the blower, or if you're removing phosphorus, the metering pump. So that it doesn't rain or snow on them. Nemají to ráda.
Upravit aeraci
If during regular inspection of the treatment plant you find that ice is forming on the surface, the fastest help is to adjust the aeration mode. By blowing in air, the contents of the treatment plant are mixed, and if the entire volume is not below zero, the ice will melt again. Therefore, divide the aeration into several shorter sections and mix more often.