Purification Efficiency Of Aquatic Macrophytes On Sewage From Jialu River And Investigate On Related Mechanism

Along with the industry and agriculture development and rapid urbanization, the massive industrial and agricultural tailrace and urban domestic sewage was directly dischanged into to Jialu River continuously, the eutrophication water destroyed the riparian vegetation enormously, which had the disastrous influence on the coast people's production and life. For the waterfront wetland technology, the engineering and operating cost was lower, and the purification and landscape effect was better. It used the plant, the soil, the microorganism and animals by the physical, chemical and biological action to purify the eutrophication water. as a producer in waterfront wetland ecosystem, hydrophytes aroused the enormous interest and researches on the effect and mechanism on purifying the eutrophication water. After investigating the aquatic plant resources in the Jialu River basin and reading related literatures, research materials had been determined, and then their purification effect and mechanism had been investigated under still hytroponic conditions. The paper mainly obtains the following result:1) In investigating the aquatic plant resources in the Jialu River basin, altogether 26 species of 17 families had been discovered. After reading related literatures, Rumex dentatus Linn., Ranunculus sceleratus Linn. and Rorippa palustris Leyss (Bess.) were selected as study materials.They distributed broadly in this basin and had the very strong decontamination ability.2)In winter and spring,purification effect analyses of three aquatic macrophytes finally demonstrated:in spring purification efficiency was higher than that in winter,and it's same to the accumulative elimination rate; In winter the magnitude order of the ability of reducing total removal rates of total nitrogen (TN) was R. sceleratus≧R. dentatus > R. palustris >CK; In spring the order of chemical oxygen demand (CODCr) was R. dentatus > R. sceleratus >CK> R. palustris; In spring the one of TN, in winter the one of CODcr and in the two seasons the one of total phosphorus (TP) was R. dentatus > R. sceleratus > R. palustris >CK.In spring, purification effect analyses of three kinds of assembly of aquatic macrophyte finally demonstrated:The magnitude order of purification effect of three kinds of assembly of aquatic macrophyte was the assembly of R. sceleratus and R. dentatus > the assembly of R. palustris and R. dentatus > the assembly of R. palustris and R. sceleratus. Purification effect of the assembly of R. sceleratus and R. dentatus was better then the sum of that of R. sceleratus and R. dentatus, so were the assembly of R. palustris and R. dentatus and the assembly of R. palustris and R. sceleratus. In spring, the result of purification effect comparison between the assembly and the single plant indicated: For TN,TP and CODCr, purification effect of the assembly of R. sceleratus and R. dentatus was better than that of R. sceleratus or R. dentatus; For TN,TP and CODCr, purification effect of the assembly of R. palustris and R. dentatus was better than that of R. palustris, but it was worse than that of R. dentatus; For TN,TP and CODCr, purification effect of the assembly of R. palustris and R. sceleratus almost was the same to that of R. sceleratus, and it was better than that of R. palustris.3) Investigate on purification mechanism of R. dentatus, R. sceleratus and the assembly of them in spring:The result demonstrated finally:For TN of Jialu river purification effect, the direct contribution rates of R. dentatus, microorganism which lived in the water and physical and chemical actions were 21.02%,14.08%, and 54.74%; For TP these three values were in turn 31.15%,23.42% and 28.72%; For CODCr the three ones were in turn 25.49%,21.07% and 34.47%. For TN, the direct contribution of R. sceleratus, microorganism which lived in the water and physical and chemical actions were 14.99%,12.69%,and 54.74%; For TP these three values were in turn 25.68%,17.02% and 28.72%; For CODCr the three ones were in turn 23.60%,22.37% and 34.47%. For TN, the direct contribution of the assembly of R. sceleratus and R. dentatus, microorganism which lived in the water and physical and chemical actions were were 20.54%,11.37%, and 54.74%; For TP these three values were in turn 28.66%,28.85% and 28.72%; For CODCr the three ones were in turn 29.59%,25.50% and 34.47%.