Study On The Structure Of Bacterial And The Purification In Wetlands

Wetlands had double prices in the water pollution removal and prettify the environment and were studied used in the countries. But, it was rarely reported what was the relationship between the effect of COD,N,P removal and the the structure of bacteria in the wetlands. The microbe inside the wetlands played an important role in the supersesson of contaminant of sewage, so it was extremely necessary to study the relationship between structure of the bacteria and the effect of purification in the artificial wetlands. Based on the test of COD,N,P and the analysis of the structure of bacteria by TGGE in the three grads of wetlands where Cyperus alternifolius,Canna lily and Calamus grow, the relationship between structure of the bacteria and the effect of purification was analysed in the paper.â‘ The Main Rusults of the reaseach:1) Effect of domestic sewage treatment by wetlandsa. The effect of domestic sewage treatment by wetlands in winter, the removal of COD: A1 was 43.6%,B1 was 52.4%, A2 was -12.5%,B2 was 39.1%, A3 was 44.6%,B3 was 33.7%, the total removal of A,B systerm was 64.8% and 80.8% respectively. the removal of TN: A1 was 20.1%,B1 was 26.1%, A2 was -7.8%,B2 was 16.4%, A3 was -5.3%,B3 was 9%, the total removal of A,B systerm was 9.2% and 38.8% respectively. the removal of TP: A1 was22.4%,B1 was 31.8%, A2 was 23.4%,B2 was23.4%, A3 was 31.5%,B3 was17.2%, the total removal of A,B systerm was 53.8% and 56.8% respectively.b. The effect of domestic sewage treatment by wetlands in summer, the removal of COD: A1 was 41.8%,B1 was 53.8%, A2 was 35.4%,B2 was 42.2%, A3 was 34.9%,B3 was 37%, the total removal of A,B systerm was 75.6% and 83.2% respectively. the removal of TN: A1 was 19.3%,B1 was 24.7%, A2 was 9.7%,B2 was 27.1%, A3 was 31.7%,B3 was 23.9%, the total removal of A,B systerm was 50.3% and 58.3% respectively. the removal of TP: A1 was20.1%,B1 was 30.5%, A2 was 19.1%,B2 was34.1%, A3 was 48.5%,B3 was26.9%, the total removal of A,B systerm was 66.6% and 66.5% respectively.2) Diversity of bacterial population structure in wetlandsa. In winter, there were few TGGE band patterns in the microbial sapmples of all grade wetlands. The number of band patterns in the TGGE fingerprints was from 16 to 23. The bands in different samples had little diferance. The bacterial diversity index of in every wetland: A1 was 2.77,B1was 2.77, A2 was2.88,B2 was 2.99,A3 was 3.14,B3 was 3.09, the bactiral index in the root of Canna lily was 2.94. The bacterial population in every wetland was not rich and there was little difference in the samples of every wetland. In winter, the richness of bacteria in the Canna lily root is almost at the same level as which in the filler where the Canna lily grow.b. In summer, there were lots of TGGE band patterns in the microbial sapmples of all grade wetlands. The number of band patterns in the TGGE fingerprints was from 24 to 36. The bands in different samples had great diferances. The bacterial diversity index of in every wetland: A1 was 3.37,B1was 3.37, A2 was3.22,B2 was 3.26, A3 was 3.4,B3 was 3.43, the bactiral index in the root of Canna lily was 3.58. The bacterial population in every wetland was very rich and there were great differences in the samples of every wetland. In winter, the richness of bacteria in the Canna lily root is more than which in the filler where the Canna lily grow.â‘¡The Main Conclotions of the reaseach:1) In the constructed wetland, system A had a better purification than system B. But A3 of system A got a better effect than B3 of system B in the wastewater treatment. So the combination of B1→B2→A3 would be the best combination of precess and had a better purification than the combination of B1→B2→B3.2) In winter, there were a weak opposite correlation between the bacterial diversity index and the removal effect of COD and TN. The removal of NH₃ and the bacterial diversity index had a weak positive correlation. But the removal of TP and the bacterial diversity index had no correlation.3) In summer, Cyperus alternifolius,Canna lily and Calamus have a vigorous growth and an increased metabolic activity. There was a positive interaction between plants and microbe. In the degradation of pollutants the impact of plant enhanced. So there was an orderless relationship and no correlation between the bacterial diversity index and the removal of COD,NH₃ and TN. And the removal of TP and the bacterial diversity index also had no correlation.