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Technical information

Decolorization processing delivery example

Introducing an example of groundwater decolorization using our filter media.
At this site, in order to use groundwater in Ibaraki Prefecture as factory water, the chromaticity and manganese that exceeded the tap water quality standards are removed with a decolorization treatment device.

● Raw water quality

item unit Numerical value Tap water standard
Water species Groundwater
place Ibaraki prefecture
pH 7.3 5.8~8.6
iron mg/L 0.1 0.3 or less
item unit Numerical value Tap water standard
manganese mg/L 0.10 0.05 or less
Turbidity degree 0.5 2 or less
Saturation degree 16 5 or less
TOC mg/L 2.3 3 or less

The color of the raw water is as high as 16 degrees, but this is because iron and turbidity are low, the TOC is slightly high, and the site was in Ibaraki prefecture where there is a lot of groundwater containing humic substances in the groundwater. Judging that the turbidity is due to organic substances due to humic substances, we delivered our decolorizing filter material, Radical Light UC3. In addition, there is an existing raw water tank, and since the raw water contained ammonia in a small amount, sodium hypochlorite is injected in front of the raw water tank in order to perform discontinuity treatment.

The filter medium to be filled in the filtration tower is radical light UC3, but manganese in the raw water was partially oxidized by injecting sodium hypochlorite in front of the raw water tank. Oxidized manganese is very fine particles and difficult to remove, so we considered injecting a flocculant (PAC). In addition, in order to inject a flocculant, anthracite was piled up on the upper layer of radical light UC3 to suppress turbidity capture and contamination of radical light UC3.

item Decolorization tower
Filter φ2000mm×SH1825mm
Filtration material filling amount (per tower) Anthracite e.s 0.8mm: 1.4m3 Radical Light UC3: 1.8m3
Filtration rate LV6.3m/hr
Chemical injection amount NaClO: Inject in front of the raw water tank and inject so that free residual chlorine of 0.5 to 0.8 mg / L is detected in the treated water.
PAC: 5 mg / L injection at the inlet of the filtration tower
Backwash process Backwash: LV35m/hr×10min
Stand still: 3 minutes
Filtration drainage: LV 6.3m / hr x 10min
Backwash frequency Once a day

As a result of delivering the above decolorizing equipment, we were able to obtain extremely clear water as shown in the table below and in the photo.

Left: Filtration tower inlet (raw water), Right: Filtration tower outlet (treated water)

item unit Filtration tower entrance Filtration tower outlet
pH 7.2 7.5
manganese mg/L 0.10 Less than 0.02
Saturation degree 16 2
Free residual chlorine mg/L 1.0 0.8


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