Envitech Corp has researched and applied New Johka, the advanced Japanese technology wastewater treatment system in Vietnam. Among the projects we have done in wastewater treatment using this technology, the most notable one is the project "Improvement of the water environment through the application of independent wastewater treatment system without collecting and mixing at Halong Bay ".
The following is a general introduction for this technology:
- To prevent the accumulation of nutrients in public water areas and remove nutrients such as nitrogen and phosphorus as well as organic substances in waste water, New Johka with advanced treatment procedure can reduce the nitrogen and phosphorus to be used practically.
Photo: Model of wastewater treatment system New Johka before being installed
- A New Johka is a wastewater treatment tank. It looks like a septic tank, but it acts as a wastewater treatment plant in miniature. The technology that Envitech Corp has researched suits small reservoirs as a small sized New Johka for an individual house with anaerobic filter tank, continuous aeration tanks, clarifier and disinfection. All treatment tanks are arranged at a small main pool of about 4m3, and wastewater through New Johka treatment can be used for applications that do not include instant drink or direct discharge into the environment.
Photo: Envitech Corp’s staffs install wastewater treatment system New Johka in Van Don, Quang Ninh
- The mechanism of phosphorus removal method that New Johka uses is electrolytic iron. Divalent iron (Fe2+) will be generated from the iron plate, which acts as an anode. Divalent iron will react with oxygen (O2) dissolved in water and be transformed into trivalent iron. Trivalent iron reacts with a phosphate ion (PO4-3) in water and becomes iron phosphate (Fe3PO4) insoluble. Phosphorus compounds generated in the filter holder are returned to the first drawer of anaerobic tank. Then, phosphorus deposition is washed out with sludge. The New Johka treatment is designed to not only remove the existing phosphorous compounds but also remove long-term stable phosphorus compounds with less maintenance in order to form non-bio membrane that is non-resistance or convolution factors between the iron plates.
- Mechanism of organic substance removal that New Johka uses is a completely normal method of forming a bio membrane and filtering bio membrane adhesion, the substrate adhesion in the form of spherical, cylindrical hollow, etc. produced by Envitech Corp to be placed into aerobic and anaerobic compartment. These substrates have specific surface area greater than 15-20 times the normal microbial substrates, thus improve the concentration of microbial adhesion and promote the decomposition of organic substances such as BOD and nitrification of ammonia nitrogen. Also, in the lower part of the filter holder, these substances can be used as filter materials.