- Sewage Treatment Plant in Japan
In municipal wastewater treatment plant in snowy regions, snow-bound in winter, taking dewatered cake out regularly is sometimes difficult. Two problems were also presented in this municipal wastewater treatment plant, i.e., the difficulty of taking sludge out using carriers in winter, which had been anticipated from the planning stage of construction; and the need for reducing the number of sludge transportations by cutting the amount of sludge to be taken out, following prefectural policy.
To solve these two problems, we proposed constructing a dewatering and drying system using the VOLUTE™ Dewatering Press and the Solapy drier, which was then introduced. The cake dewatered with the Volute Dewatering Press is fed consecutively into the Solapy drier, and discharged as dried sludge with a water content of about 40%. With this drying process, the volume of sludge is reduced to about 1/4 of the dewatered cake, and the amount of sludge to be taken out can be significantly cut. Since dried sludge does not rot easily, long-term storage causes no foul odors, and the problem of the limited number of transportations in winter has been solved. The sludge is sent to a compost center, in which the dried sludge is utilized as moisture conditioners.