Effectiveness Of EM-macrophyte Interaction On Remediating Eutrophic Water

With the rapid development of industry and the growth of population, water eutrophication caused by daily sewerage discharge and non-point pollution has been drawn great attention. The physical-ecological remediation is a new measure for controlling water eutrophication. Many research evidences have proved that use some large aquatic plants to remove nitrogen and phosphorus is an effective way to treat, adjust and control water eutrophication. There are a lot of repots on using aquatic plants-Effective Microorganism to purify the polluted water, however, little is known about the effect of aquatic plants combined with microorganisms. The objectives of this study were to examine the effectiveness of aquatic plants combined with effective microorganisms (EM) on remediation water eutrophication. The main contents include: (1) The effect of using EM to treat polluted water in different conditions, (2) Combination of EM with Jussiaea stipulacea Ohwi in different proportions to treat the polluted water. (3) Use immobilized technology to study the effect of EM on purifying the polluted water. (4) Effect of EM combined with higher plants (aquatic plants and terrestrial plants) to treat discharge wastewater from sewerage treating factories. The results obtained are summarized as follows:1. The results from the experiments of using EM to treat sewerage under different conditions (quantity, pH, DO, temperature) showed that microbial proportion and treating conditions were different from the N and P pollution levels. COD of the EM is greater, the inoculated amounts of EM in the treatment should no to be too large, otherwise it will worse the effects. The best treatment conditions were the ratio of EM (V) to sewerage water (V) being 1/1000, with continuous aeration, and at T>25℃. To remove P and N. the best condition is EM/ seweragewater=8/1000, with intermittent aeration, and at T> 25 ℃ and pH of neutral to soda. The later conditions are more economic and realistic, as compared with the formers.2. Using microorganism-EM combined with higher aquatic plants-Jussiaea stipulacea Ohwi to remediation the eutrophic water. The results showed that the quantityof EM added affected the effectiveness of treatment. At EM / sewerage water of 5/1000, EM treatment alone removed TN, NH/-N, TP by 39.25%, 61.67% ft 56.58% , respectively under experimental conditions. However, the quantity of EM should not add too high in order to decrease BOD5 of the water. The combination of aquatic plant with EM obtained better effectiveness in removing nutrients and BOD from the waste water.. The removal of TN with the treatments of EM(0.01%)+P, EM(0.05%)+P, EM(0.1%)+P and EM(0.5%)+P increased by 4.45%, 24.23%, 11.26% and 11.64%, respectively, as compared with treatment of EM(0.01%) , EM(0.05%), EM(0.1%) and EM(0.5%). And the removal of TP enhanced by 22.91%, 17.05%, 14.55%, and 10.94%, respectively. Nutrient removal from the wastewater was highly dependent on the quantity of microorganisms in the water. The higher the microorganismas number, the better the wastewater was purified.3. Immobilized microorganism technique was used in the treatments of sewerage water. The results showed that EM could remove N and P effectively, especially, NH/-N, with the free EM havin better effects than immobilized EM. The reason is unkown> probably However, EM combined with Jussiaea stipulacea Ohwi showed the better effects than single EM. Within 12 days treatment, of the removal of NH4+-N, TN and TP with EM+P were by 98.1%, 53.6%, and 47.4%, respectively.4. EM combines with terrestrial plants {Lolium perenne L., Beta vulgaris, Silphium perfoliatum L., Pistia stratiotes L.). The results of treating the sewerage of sewerage factories show;use Lolium perenne L. and Silphium perfoliatum L. has ideal purification results. They get rid of TN raises by 43.33%, 42.78% and TP raises by 54.80, 53.77% in comparison. At the same time, they get rid of CODmh raises by 47.00%, 28.40%, and Chl-a by 52.74%, 52.04%. When EM combines with plants Beta vulgaris has the best results. SP+EM can get rid of TN, TP, CODMn and Chl-a by 96.17%, 83.85%, 73.67% and 94.84%. The length of root has relation with the result of getting rid of nitrogm and so on. That is Rtn=0.73, RNOx-n=0.67, Rnh4-n=0.45, Rtp=0.36, Rcod=0.44, Rchu=0.36. Lolium perenne L, Beta vulgaris and Silphium perfoliatum L. grew large root systems, with lengths exceeding 29cm. It appears that combining EM with higher plants (aquatic plants and terrestrial plants) could effectively remedied sewerage water, and remove N and P.