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Sewage Treatment

Sewage Treatment Works

- After the addition of WK for about 3 months, the excess organic sludge amounts to zero.
- Enormous reduction of running cost (coagulant cost, sludge disposal cost)
- Energy saving (30% - 50% reduction of electricity, transportation, etc)

1) The 5th Sewage Treatment Works of Kunming City, China

sewagepix

Daily change of dewatering sludge amount(m3) after the addition of WK at 5th Sewage Treatment Works, Kunming city, China
WK addition period: 2005:4.9 ~ 2005.8.02; treatment capacity  75,000t/day

dailychangedewatersludge

2) Organic sludge decomposition at Sewage Treatment Works in Yeoncheon Province, Korea

organicsludgedecomposition

Application in Sewage Treatment Works

The sewage treatment has been performed mainly by activated sludge processes, where organic compounds are decomposed under aerobic conditions in an aeration tank. Undecomposed organics are treated by coagulants, and percipitate particles called floc are separated by a filter (i.e., solid-liquid separation). Currently, disposal of the filter cake, however, has become a serious problem.

For these about ten years, purification processes based on biological principles such as so called effective microorganisms, etc. have been applied to aquatic spheres, sewage treatment works, etc. Bio-based purification processes actually depend on the site to be applied, i.e., bacteria living in and/or on the site. Accordingly, the applicability, validity and efficacy of the bio-based processes have not been decided yet. Biological species generally tend to have little resistance to chlorine and other chemicals, and hence stable applications of the bio-based processes seem to be difficult.

One the hand, WK-based treatment processes are neither aeration nor bio-based processes, but utilize biocatalysis of WK. WK (liquid) is composed of bromeline enzyme, fermentation suppressed yeast, and other additives. WK function as a biocatalyst; the activation of effective microorganisms is caused owing to WK's synergetic effect. The activation of bacteria for organics-decomposing bacteria, nitrification bacteria, thiobacillus thiooxidans, (sulfur-oxidation bacteria) living in the aerobic region ten to induce complete decomposition of organic compounds, conversion of ammonia and hydrogen sulfide to nitrate and sulfate, respectively. Activated denitrification bacteria lining in the region where DO00 actively convert nitrate to nitrogen gas. In the anaerobic region, WK can also activate organics- decomposing bacteria and phototrophic bacteria such as green sulfur bacteria, purple sulfur bacteria and purple non-sulfur bacteria living in the anaerobic area. Both green sulfur bacteria and purple sulfur bacteria begin to take place the photosunthesis to consume hydrogen sulfide (as an electron donor). The purple non-sulfur bacteria also begin to take place the photosynthesis to consume organic materials (as an electron donor). the decomposition of sedimentary sludge is promoted through the synergism of organices-decomposing anaerobic bacteria fermentation-suppressed yeast. It should be noted that WK fulfils the function of decomposition of sedimentary sludge along with the improvement of water quality.

In the dark area like sewage treatment facilities, hydrogen sulfide can be oxidized by thiobacillus thiooxidans, living in the aerobic phototrophic bacteria to consume hydrogen sulfied as an electron donor. There is no need of saying that thiobacillus thiooxidans has been activated by WK.

By the addition of WK, MLSS value tends to increase by 2 to 5 times in comparison with the standard regulated in sewage treatment facilities. Nevertheless, no bulking phenomenon takes place. The microorganisms are related to each other in a food chain. A reasonable food chain like that in natural eco-systems, is believed to be built up in WK-based treatment processes, being different from those in conventional activated sludge processes. The fact that bulking phenomenon takes place at such high MLSS values can not be simulated in any other treatment processes.

Dr. Hidehiro Kumazawa, professor of Toyama University, Department of Systems Engineering of Materials and Life Science, and Visiting Professor of Yangzhou University, College of Chemistry and Chemical Engineering. His major is Catalytic Engineering, which is highly related to the present WK-based technology. He summarizes the role of WK in the purification of aquatic systems as four time-series maps which are attached below. Please refer to them along with Waterkeeper Technology and Cerfitication of safety of WK.

The safety of WK was certificated by two methods:

1) Results of water quality test
2) Results of quantitative analysis

Why no any bulking phenomena accur in sewage treatment works with added WK?

- WK functions as a biocatalyst; the activation of effective microorganisms is caused owing to WK's synergetic effect. Activated microorganisms are believed to be related to each other in a food chain similar to those in natural eco-systems. Both water purification and decomposition of organics are accomplished simultaneously. Even though MLSS values are increased a lot in WK-based treatment processes, it should be noted that no bulking phenomenon takes place.
- The increase in MLSS value in WK- based facilities results in an decrease in T-N value.
- There are no adverse effects on existing activated sludge treatment facilities by the addition of WK. In fact, there have been no adverse effects for these 3 years in an activated sludge treatment facility in Japan.
- WK Technology provides both complete prevention of "bulking phenomenon" even under high MLSS conditions and complete decomposition of sludge.

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