02252nas a2200241   450000500170000000800410001703500150005810000180007324500460009126000520013730000100018949000260019950001640022550200580038952012410044765000280168870000290171670000370174570000450178271000600182781000580188785600650194520260818113506.0011298s1986    th      r     000| 0eng d  a.b102729871 aHsiao, Wen-ho10aFate of nitrogen in polluted water bodies  aBangkok :bAsian Institute of Technology,c1986  a53 p.1 aThesis ;vno. EV-86-6  aA research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development  aThesis (M.Eng.) - Asian Institute of Technology, 1986  aThe activities of nitrogen transformation including nitrification,  denitrification, ammonia release and ammonia adsorption were studied.  River water and sediment at three different points on Chao Phraya River were  collected and their bacteria activities were examined using batch experiments.  Sediments can play an important role in ammonia transformation processes. Sediments contain much of the nitrification and denitrification  bacteria and increase the rates significantly.  Nitrifying activity decreased with increasing the pollution.  Ammonia release from sediments reflects that sediments can keep large  amount of ammonia.  Ammonia adsorption by the suspended silt and by the sediments was not  clearly shown. However, sediment may play important role in ammonia  adsorption because sediments contain clay like zeolite and the release of  ammonia from sediment was observed.  Low ammonia content in Chao Phraya River, which receives Bangkok city  domestic sewage and many factory discharges along the river with insuffi-  cient treatment, can be due to high ammonia transformation activities. High  nitrification and denitrification potentials decrease the ammonia concen-  tration rather quickly after it was discharged.   0aWaterxNitrogen content1 aHanaki, K.,eChairperson1 aFude, I.,eExamination Committee0 aSamorn Muttamara,eExamination Committee2 aThe Government of Republic of China,eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. EV-86-6  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B19628