A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering

Thesis (M.Eng.) - Asian Institute of Technology, 1992

Due to congested traffic, overcrowded people and factories fo l lowed by extremely rapid economic development, Taiwan is confronted with serious environment pol lution problems . One of t hem, water pol lution was focused in this study. Data ana l ysis of wastewater treatment and environment showed that 713 of Taiwan coastal area is too fu ll of BOD & Cu to be used in swimm ing and breeding h igh-value seafood, and that 34 .83 of the total length of primary rivers is so pol luted for swimm ing and supplying high-quality drinking water . The data showed that water pollution control measures in Taiwan should be developed, such as extension of the separated sewer system over the cities, completion the network of moni taring stat ions i n water bodies, and execution of total control of maximum allowable quantity of pollutants in respective rivers. The needs of Taiwan are derived from the resul ts of analysis and future development mentioned above . It was shown that wastewater treatment p l ants combined carbon oxidiation with ni trif icat ion-deni trif icat ion process is t he needs of Taiwan at present and in the future. A mathematical model, which is abl e to simu late carbon oxidation wi th ni tri f icat ion-deni tri f icat ion process, was verified by the p lant data of a typical community wastewater treatment p l ant, the Min Shen Wastewater Treatment P lant located in the north of Taipei, Taiwan and running since 1971 . After verification, about 60 numerical experiments were executed under different i nner and outer conditions for the determination of the optimal design and operation conditions of the wastewater treatment p l ant. The simulation results indicated t hat high removal efficiency of BOD could be performed by the fol lowing methods; i ncrease of DO or Kla value in aeration tank, increase of the aeration tank vo lume, change of the follow pattern in aeration tank to p lug-flow or step feed, increase of temperature, and addition of a ni tri f icat ion- denitrif icat ion process. Nitrification react ion could be promoted by increase of DO or ~a value in aeration tank, increase of MLVSS in aeration tank, extension of aeration tank vo lume . In add it ion, removal efficiency of SS could be improved by extending the volume of sedimentation tank.