PHYTOREMEDIATION OF CONTAMINATED WATER IN THE UPSTREAM OF DAM RESERVOIRS

Abstract

Rural sewage installation is often adopted in the upper region of dam site. Treated wastewater from the system has still much nutrients and sometimes causes eutrophication in reservoirs. To reduce the pollutant load into the reservoir, purification experiment of wastewater using plants was carried out in the cooperation of Tottori University and the Ministry of Land, Infrastructure and Transport.

From the analysis of water quality through the experimental period, it is found that the average removal rate of the total nitrogen was more than 50 % and the average removal rate of total phosphorus is more than 30 %. The plant analysis showed that there was a large difference in time of maximum growth and uptake of nitrogen and phosphorus between plant species. Although the remediation of eutrophicated water by plants is highly effective, the growing season of plant species should be carefully considered.