J. Technology and Education, Vol.20, No.1, pp.21-29 (2013)

研究論文

2007年~2011年における門池の水質の変化

 

芳野 恭士*、芳野 文香、芳野 広起、竹口 昌之

沼津工業高等専門学校　物質工学科（〒410-8501　沼津市大岡3600）

*k-yoshino@numazu-ct.ac.jp

 

Change of Water Quality in Kado-ike Pond from 2007 to 2011

 

Kyoji YOSHINO, Ayaka YOSHINO, Hiroki YOSHINO, Masayuki TAKEGUCHI

Numazu College of Technology (3600 Ooka, Numazu, Shizuoka 410-8501, Japan)

 

 

Abstract

In this study, we monitored changes in the water quality in Kado-ike, an irrigation pond in Numazu City, Shizuoka, every year in August from 2007 to 2011. In Kado-ike, the water color was dark green, and algal bloom was seen mainly at points southeast and northwest. Cyanobacteria and spirogyra were observed under a microscope. The pH of the water at any point in Kado-ike was 8 or more alkaline, making it suitable for the proliferation of algae. The chemical oxygen demand tended to be high on the southeast side. Various nitrogen and phosphorus compounds, witch would be the main causative materials of eutrophication, were thought to flow mainly from the north side of the pond. It is necessary to take positive measures for water quality purification by using the improvement of a water cycle; removal of the contaminants by activated carbon, carbon fiber, and some plants; and other techniques.

Key words: Water quality, Eutrophication, Kado-ike