Abstract
Deposition in a sedimentation tank may become important resource because it contains soil and nutrients. The purpose of this study was to examine the form characteristics of paniculate nitrogen as related to its settling and particulate nitrogen trap efficiency in an ideal settling tank. For the purpose of this study, observing suspended soil particles with a digital microscope, measuring particulate nitrogen concentrations classified by the suspended soil particle size, and calculating trap efficiency based on the clarification theory of an ideal settling basin were conducted. As a result, it was found that the particulate nitrogen concentration of the suspended soil classified as fine sand was higher than that of silt and clay. It was also found that particulate nitrogen was nitrogen as a constituent of the organic matter in a micro aggregate, so that it was relatively easy to settle. The results show that particulate nitrogen is removed easier than suspended soil, so that its trap efficiency in sedimentation tanks is higher than that of suspended soil.
