INFLUENCE OF LIGHT ON A MICROBIAL RIVER WATER ECOSYSTEM AND ITS SELF-PURIFICATION POTENTIAL

Abstract

Self-purification in rivers is mainly conducted by microorganisms attached to the river bed. To enhance the self-purification capacity, several processes or technologies have been proposed to improve the river water quality and preserve biodiversity. From the environmental engineering perspective, finding influential parameters and their effective control are effective in improving river water quality. However, there are numerous parameters affecting the self-purification capacity of rivers, and quantitative evaluations of these parameters have not been completed. In this study, the influence of light on both the microbial river water ecosystem and its self-purification capacity were investigated. Lab-scale experimental facilities (artificial river) were set, and artificially contaminated river water was introduced to the system. Furthermore, through a mass balance analysis, we realized that the clean river water conditions might be affected more by sunlight compared to water contamination; this is due to the large relative intensity of organic carbon loading by photosynthesis.