Aquatic Plant Purification Different Concentration Gradient Sewage Experimental Study Ability

With floating culture the Hydrocotyle verticillata,Acorus calamus and Canna indica,the effects on getting rid of total nitrogen,ammonia nitrogen,total phosphorus and chemical oxygen demand in three types of sewage(low concentration,medium concentration and high concentration)were studied.It can provide experimental basis and technical support for plant selection in biological sewage treatment and ecological restoration projects.The main results were summarized as follows:(1)Under the same external conditions,such as light illumination,temperature and humidity,different aquatic plants in the same concentration of sewage have different sewage purification,same aquatic plants in three types of sewage have different sewage purification,and the aquatic plants in different time also have different rates of purification in water.(2)The effects on getting rid of total nitrogen and total phosphorus by aquatic plants were better than control group.Under the low concentration,medium concentration and high concentration treatment at 49 th day,the removal rates of total nitrogen and total phosphorus by Hydrocotyle verticillata,Acorus calamus and Canna indica were between 90%-99%.(3)The effects on getting rid of ammonia nitrogen by aquatic plants in the high concentration at 14 th day were reached 100%,while the removal rate by the control group at 42 th day was reached 100%.The results indicated that the aquatic plants enhance the water self-clarification ability.(4)Under the three types of sewage,the low concentration,the medium concentration and the high concentration,the removal rates of chemical oxygen demand by aquatic plants and control group have no significant difference.The concentration of chemical oxygen demand recovered at the end of the research.