Improving Water Quality of a University-Managed Biotope

Abstract

“Biotope” was coined in Germany by combining the ancient Greek word “Bios” which refers to organisms and life, and “Topos”, which refers to a place. In Germany, biotopes have been attracting attention since the 1970s, when environmental problems caused by industrialization became more serious. Since the end of the 20th century, biotopes have been created in various parts of Japan, including tidal flats, wetlands, lakes, rivers, and other water bodies, as well as forests and grasslands. It is still offered as an educational opportunity in Japan. They are prone to water pollution and need to be improved because biotopes are closed environmental water bodies. In Japan, there is no set environmental level for the water quality of biotopes. In this study, we conducted water quality measurement and purification experiments in the biotope in the campus at Tokyo University of Agriculture, Japan. This study aims to evaluate total nitrogen in a biotope. The biotope at Tokyo University of Agriculture had not been managed regularly for a long time. First, the filtration system installed in the biotope was not working, so it was fixed. For measuring water quality, water samples of the biotope at Tokyo University of Agriculture were collected twice a week in a month. And the concentrations of total nitrogen (TN) were measured by a spectrophotometer. In the biotope at Tokyo University of Agriculture, total nitrogen ranged from 1.14 to 3.76 mg/L, which is high compared to the environmental level set by the Ministry of the Environment for lakes and marshes in Japan. Through a set of field observation, this study attempted to improve the water quality the biotope at Tokyo University of Agriculture, which has been unmanaged for more than long years. Water quality measurement and purification experiment revealed that total nitrogen was improved.