Study on the removal effect of N and P by a new type artificial floating-island system at Bai Lian Jing River in Shanghai

DU Jia-mu,ZHANG Yin-jiang,ZHU Wen-bin,ZOU Dan-yan,LUO Kun,ZHANG Lei,HE Pei-min (Key Lab of Aquatic Genetic Resources and Aquacultural Ecology Certificated by the Ministry of Agriculture,Shanghai Fisheries University,Shanghai 200090,China)

floating-island raft;Arundo donax var versicolor;nitrogen;phosphorus;removal rates;Bai lian jing River

A new type artificial floating-island raft was designed for a trial bioremediation at Bai Lian Jing River in Shanghai.An aquatic plant,Arundo donax var versicolor,was used to absorb nitrogen and phosphorus nutrients in the floating-island raft.It was showed that the floating-island raft could stably floated in the water of Bai Lian Jing River when river strobes sharp opened or closed and the water depth changed largely.It also had the functions against insolation and rainstorm.The floating-island raft could be regulated in different water depth by pumping water in or out.The maximum raft flotage was 800 N.And the raft security could be increased for several rafts connected one by one.Arundo donax var versicolor planted at basketries with different density below water surface in the floating-island rafts,and could reduce N and P concentrations efficiently.When the planting density was 30/m2,the removal rate of total N and P in Bai Lian Jing River water were as high as 81.79% and 55.88%,respectively.It indicated that the floating island system with Arundo donax var versicolor was characterized of improving water quality and water environment efficiently.