Improvement of Water and Soil Conditions of Stream with Charcoal Made on Thinnings of Japanese Cedar

Research Project

Project/Area Number	10660154
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	林学
Research Institution	Minamikyushu University
Principal Investigator	KITAMURA Hirokazu Minamikyusyu University, Faculty of Landscape Archite Professor, 園芸学部, 教授 (90214816)
Co-Investigator(Kenkyū-buntansha)	TAKAYA Sheizi Minamikyusyu University, Faculty of Landscape Archite Professor, 園芸学部, 教授 (40070081)
Project Period (FY)	1998 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥1,300,000 (Direct Cost: ¥1,300,000) Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Keywords	thinnings charcoal of Japanese cedar / adsorbility / infiltration capacity / suspended particle / stream environment / disturbed filtration / citizens' campaign / planting environment / 攪乱吸着 / 溶存性BOD / 流木処理
Research Abstract	Nowadays, charcoal is used in many fields, such as soil and water quality improvement, because of its remarkable adsorbility. However, the effects and functional mechanism of adsorption of charcoal has not been varied correctly, prevailing vague image for charcoal. Thus, the purpose of this study is to identify the adsorbility and its functional mechanism of charcoal relations to stream environmental improvement by laboratory experiments with charcoals made on thinnings of Japanese ceder and several kind of broad-leaved trees, marketing charcoal for recreational uses and Bench-tan (Japanese traditional charcoal). Overall descriptions and results of laboratory experiments are follows. 1) After entering 500g of each charcoal into 15l of distilled water, the nutrient-concentration fluctuations with time attributed to elution were measured with ion chromatography. It was indicated that charcoal made on thinnings of Japanese cedar contains considerably lower concentrations of ClィイD1-ィエD1 and … More KィイD1+ィエD1 than marketing charcoal for recreational uses and Bincho-tan, and the composition of charcoal made on thinnings of Japanese cedar remarkably pour. These impurities of marketing charcoal for recreational uses and Bincho-tall would be based on the differences of manufacturing process such as temperature of charcoal making. Since these eluted nutrients should interfere with adsorbility of charcoals. 2) It was suggested that adsorbility of charcoal made on thinnings of Japanese cedar is as strong as that of Bincho-tan. It would be because that charcoal made on thinnings of Japanese cedar contains considerably high porosity. 3) 50g of charcoal made on thinnings of Japanese cedar shattered into fragments with an average diameter of approximately 0.5m were placed in a stainless-basket and hunged in water containing 1500 ppm suspended particles with a diameter of smaller than 50μm which were sampled in Okinawa Island in order to estimate the absorbility of charcoal made on thinnings of Japanese cedar. SS concentration of the water were reduced from 1500 ppm to 40 ppm during 7 days and the remarkable adsorbility of charcoal made on thinnings of Japanese cedar available for suspended particles was shown. The adsorbility of charcoal made on thinnings of Japanese cedar rises up to five-fold by disturbing the water using magnetic stirrer because the contact time of particles with charcoal made on thinnings of Japanese cedar becomes longer. This process eliminating suspended particles rapidly was named "disturbing filtration". 4) The adsorption rate of charcoal made on thinnings of Japanese cedar by disturbing filtration is more than 5 times as fast as ordinary filtration which passes water containing suspended particles through charcoal layer simply. Less