Water Treatment Facility
Rain that falls onto the final landfill site penetrates through the waste and comes out as dirty water.
Water treatment facilities are used to process dirty water (leachate) into clean water that does not appear to affect the environment.
The Ueno Eco Center is Japan's first private final landfill site that introduced vacuum evaporation processing equipment to its water processing facility, which removes heavy metal and salt at a stage prior to biological treatment. The facility is of advanced composite processing type capable of performing stable water treatment.
Furthermore, YAMAZEN has in-house water quality criteria that are stricter than national and prefectural water quality criteria, thus eliminating the impact on the environment.
Phase-1 water treatment facility: 70 to 100 m3/day
Phase-2 water treatment facility: 110 to 150 m3/day
Maximum: 250 m3/day
Water quality comparison between leachate and discharged water (maximum value)
(All items are in mg/l except for pH)
|Hydrogen ion concentration||Biochemical oxygen demand||Chemical oxygen demand||Suspended solids||Total nitrogen|
|Effluent standards (by law)||5.8～8.6||120||120||150||60|
|pH||Water with a pH of 7 is neutral, water with a pH less than 7 is acidic, and water with a pH greater than 7 is alkaline.|
|BOD||Biochemical oxygen demand (BOD) is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down contaminants (organic matter) present in a given water sample.|
|COD||Chemical oxygen demand (COD) is the amount of oxygen converted from the amount of oxidizing agent necessary to break down contaminants (organic matter) present in a given water sample.|
|SS||Suspended solids (SS) are minute substances that float in water, causing turbidity.|
|T-N||Total nitrogen (T-N) is a substance necessary for life, but an excessive amount of T-N can lead to water quality deterioration and the growth of plankton.|
|Leachate||Rain that falls onto the final landfill site penetrates through the waste and comes out as leaching water that contains pollutants.|
|Calcium removal process (Primary treatment)||
The equipment used in this process removes calcium present in leachate.
At this stage, sodium carbonate is added to the wastewater so that the sodium carbonate will react with calcium, which will result in a precipitate of calcium carbonate to be removed. The removal of calcium will reduce the trouble of calcium scaling in the piping or pumps.
|Evaporative concentration process (Secondary treatment)||
The equipment used in this process removes salt and heavy metal present in leachate.
All leachate finished with primary treatment is evaporated at this stage, and only distilled water (colorless water) is sent to the biological treatment stage. Liquid (concentrate) remaining will be further concentrated until salt precipitates.
|Biological process (Tertiary treatment)||
The equipment used in this process decomposes and removes organic matter present in the distilled water by the action of microorganisms.
YAMAZEN's biological process uses a nitrification/denitrification process of nitrification liquid circulation type and efficiently removes organic matter and nitrogen.
|MF membrane process||
Microfiltration (MF) membrane with a pore size 0.4 μm separates microorganisms (sludge) from the treated water.
This membrane process makes it possible to obtain clear treated water at a level that does not require coagulation/sedimentation or sand filtration process stages.
|Activated carbon adsorption process||
The equipment used in this process uses activated carbon to adsorb and remove trace constituents, such as color components and odors, present in treated water.
Treated water after the adsorption process of activated carbon is clear, colorless, and odorless and called final treated water.
The equipment used in this process uses a chlorine agent to sterilize general bacteria (E. coli) present in treated water.
Sterilized water is discharged as effluent into rivers.