USING PLANTED CONSTRUCTED WETLANDS TO TREAT WASTEWATERS FROM CIRCULATING AQUACULTURE OF CLARIAS FUSCUS

The vertical-flow constructed wetland which was in the base of gravel-Canna indica was designed and applied to purifywastewaters for reusing in the culture of Clarias fuscus. Observations were taken on parameters of water quality during breeding Clarias fuscus. The results showed that the planted constructed wetland had considerably effective purification in water body ofaquaculture. The average removal rate of BOD5,COD,and TN of wastewaters during breeding periods was 81.77 %,55.55 %,and65 % respectively.After being purified,the water quality partly accorded with the National Standard of Fishery Water Quality,andthe culture water could be recycled. However,because there was no treatment in the control pond,BOD5,COD and TN increasedcontinually. The turbidity degree was obviously higher than that in the experimental pond.Algae bloomed in the control pond. Thisstudy demonstrated the advantage for planted constructed wetlands which were simple mechanisms and easily generalized to treat-ment of wastewaters in circulating aquaculture.