Teaching Materials for Environmental Education-Water Circulation System and Clarification Power in Nature-

作为环境教育的教材之一，环境污染物的简单测定方法的发展和自然界中几种有趣的澄清能力已被广泛研究并应用于义务教育的教学中。此外，已发现河流中的沉积物或桑迪土壤对表面活性剂的生物降解和吸附都有效。另一方面，阐明了土壤的有效性（缓冲作用和吸附能力），考察了金属在酸性溶液中的溶出情况以及溶出的金属对水生杂草生长的影响。所研究的金属是铜、铁、铝和锌，它们被用作硬币、罐和干电池。酸度的增加会导致大量的金属溶出，对水草的生长产生不利影响。特别是Cu和Zn都产生显著的阻碍。另一方面，水葫芦是一种水生杂草，它吸收一些有害金属，可用于净化河水。将改进的二氧化氮测定方法应用于熊本县大气污染状况的测定。结果发现，二氧化氮的产生量与天气有很大的关系，一片植物的叶子就可以把空气中的二氧化氮清除掉，最后发现大自然想出了许多聪明的办法来保护自己免受污染。

As one of the teaching materials for environmental education, both developments of simple determination methods for environmental pollution matters and several kinds of interesting clarification powers in nature have been widely investigated and applied to teachings in compulsory education.It was found that river water could be easily biodegraded of most surfactants that were the main constituents of domestic waste water. Moreover, sediments or sandy soils in rivers have been found to be effective for both diodegradation and adsorption of surfactants. On the other hand, it was clarified the soil availability (the buffer action and adsorption power).The metal elution in acidic solution and the influence of metal eluted for the growth of aquatic weeds have been examined. The metals examined are Cu Fe Al and Zn, which are utilized as coin, can and dry cell. The increase in acidity causes a large a mounts of metal elution and has a negative effect on the growth of aquatic weeds. In particular both Cu and Zn give remarkable hindrance. On the other hand, the water hyacinth, a kind of aquatic weed, absorbs some harmful metals and is available for clarification of river water.The improved determination method for nitrogen dioxide was applied to the measurement of the air pollution condition in Kumamoto prefecture. It was found that the amounts of nitrogen dioxise and weather considerable correlated to each other, and nitrogen dioxide could be removed from air with a leaf of plant.Finally, it was found that the nature thought of many clever tricks to protect themselves against the pollution.