Local treatment plants LOS

The homogenizer is designed to equalize the influx of wastewater in terms of productivity and composition. Water enters the homogenizer at different hourly flow rates, depending on the population’s water use schedule. Water is supplied from the homogenizer at a constant flow rate equal to the average hourly water flow rate. The presence of a homogenizer helps make pumping water for biological treatment as stable as possible, thereby improving the quality of biological treatment. The homogenizer also has a trash-holding basket at the inlet, with a smaller opening than in the KNS. The basket serves as a mechanical cleaning of waste.

After the homogenizer, the wastewater enters the denitrifier, where a recirculation flow from the nitrifier and activated sludge from the secondary settling tank are added to it. The denitrifier constantly mixes wastewater and sludge to create optimal conditions for denitrification processes.

From the denitrifier, the wastewater mixture passes into the nitrifier, where it is purified with activated sludge. Air is supplied to this compartment for the life of aerobic bacteria. A recirculation pump with a constant flow rate is installed in the tail part of the nitrifier.

After the nitrifier, the water enters the secondary settling tank, where, due to the shape of the settling tank, the flow direction changes, the water moves first in a downward flow, and then in an upward flow, thereby separating and settling the activated sludge at the bottom of the settling tank. The settled sludge is pressurized into the denitrifier, and the clarified water is supplied for post-treatment.

In BioLOS - 5, 10, 15, 20, 30 installations, a sand filter is used as a post-treatment in which water passes through a layer of sand and gets rid of fine pollutants. Air is supplied here to periodically loosen the sand. The BioLOS-50 installation uses a drum microfilter. The principle of operation of mesh drum filters is as follows: The treated water flows continuously through the inlet pipe into the drum, is filtered through mesh filter elements and enters the installation chamber, from where it enters the channel that discharges the purified water through a weir. The strainer drum is not completely immersed in water - its upper part is located above the water (approximately 0.15 diameter). When the filter element is in the upper position, contaminants are washed away by jets of water from the washing device into hoppers located inside the drum, from where they enter the drain pipe and are discharged into the sewer. The mesh drums are washed periodically depending on the degree of contamination of the filter mesh.

The main method of disinfection of biologically purified water in BioLOS installations is UV disinfection. Therefore, after post-treatment, the purified water passes through a block with a UV disinfection lamp, in which bacteria are destroyed due to the saturation of the water with UV light. If necessary, for deeper disinfection, water after UV cleaning is supplied to a contact tank, where a hypochlorite solution is dosed. Each type of disinfection covers the full need for disinfection, so there is no need to use both methods at the same time. During operation, you can choose one of these disinfection options, or, if there are increased requirements for disinfection or there is a risk of failure of one of the types of disinfection, use both methods.

The sludge stabilizer is designed to store and stabilize excess sludge, which is a container with aerators installed inside. If necessary, the sludge stored in the stabilizer will help restart the treatment plant, without the need to import sludge from another treatment plant. Stabilized sludge is better amenable to dewatering processes, therefore the stabilizer is an important step in the subsequent dewatering of sludge.

The sludge dewaterer is designed to separate water from stabilized sludge. For treatment facilities with a capacity of up to 100 m3/day, it is possible to use a bag-type dehydrator, which is a metal structure with attached bags made of non-woven filter material. The sludge mixture, passing through this material, allows water to pass through, leaving partially dehydrated sludge inside the bag. The dewatered sludge is then transferred for disposal in a manner approved by the project. The design of the dehydrator allows you to repeatedly replace filled bags with sludge with new bags. To speed up the process and increase the percentage of water release, it is recommended to use a flocculant supply to the dehydrator. With increased requirements for sludge dewatering, it is possible to use a screw-type sludge dewaterer, which is more effective in terms of water loss and sludge moisture compared to a bag-type dehydrator.