PREVENTION OF ALKALIZATION OF REGULATING POND FOR RAINWATER BY SHADING

Abstract

 As water in regulating pond for rainwater at Sankyo landfill site in Nagasaki city tends to be alkalized, measures to prevent alkalization should be implemented. Prevention of photosynthesis of algae is required to avoid the alkalization. Shading is mentioned as one of the prevention methods. In this study, the porpose is selection of shading materials that have the effect of prevention of alkalization and of low cost. Shading cover, PET bottle painted black, PET bottle containing black ink and covered PET bottle could keep average pH within the limits of environmental standerds. Around 20 μmol/m²s or low can be proposed as one of the photon standards for prevention of alkalization. Shading cover or PET bottle containing black ink can be selected as shading materials that have the effect of prevention of alkalization and of low cost.