Abstract
We analyze effluent water quality and electricity consumption after in troducing advanced treatment in sewage treatment plant. We define 'advanced treatment ratio' as volume of treated water through advanced treatment processes divided by total volume of treated water in plant. Advanced treatment ratio represents degree of introducing advanced treatment. We build two types of equation. One represents relation between effluent water quality and advanced treatment ratio, the other between electricity consumption and advanced treatment ratio. Each equation is fitted by least squares on 808 samples: 8 fiscal years operation data of 101 plants working in Kanagawa, Tokyo, Saitama and Chiba areas, and coefficient of advanced treatment ratio is estimated.
The result is as follows.
(1) After introducing advanced treatment aimed at nitrogen removal, T-N in effluent water decreases by 51.3% and electricity consum ption increases by 52.2%.
(2) After introducing advanced treatment aimed at phosphorus removal, T-P in effluent water decreases by 27.8%.
Using the above result, we try prioritizing 71 plants in Tokyo Bay watershed about raising advanced treatment ratio, so that, in total, pollutant in effluent water decreases with minimized increase of electricity consumption.
