| Sewage discharge,sewage quality were investgated and analysized, and treatment effects of domestic sewage were studied by constructed wetland treatment system from student dormitory building (the11th student dormitory building for girl studeng and the17th student dormitory building for male student) in Hunan Agricultural University.The results are as follows:1. Analysis of discharge characteristics ofsewage fromstudent dormitory building1) the sewage emission analysis(1) Diurnal variation of the sewage emissionThe drainage peak period of11th students’ dormitory building appears (in the order) during6:00a.m.to8:00a.m.,12:00a.m.,9:00p.m.to12p.m.; and the drainage peak period of17thstudents’ dormitory building appears (in the order) during7:00a.m. to12:00a.m.,12:00a.m. to2:00p.m.,9:00a.m.to12:00p.m.. The peak hour, with a long duration, of17th students’ dormitory drainage is earlier of an hour than it of11students’ dormitory building. Therefore, the living sewage emissions in student apartments have three peaks emerging in the morning, at noon and in the evening, and the three periods of the displacement accounts for more than85%of displacement throughout the day.(2) Weekly variation of the sewage emissionThe characteristics are performed as the equality from Monday to Friday, increases at the weekend; displacement in11th students’ dormitory building has an significant increase (approximately20%) at the weekend as compared to the period from Monday to Friday; while there is a small growth of5%in17th students’ dormitory building(3) Moonthly variation of the sewage emissionThe minimum displacement in these two buildings appears in the summer vacation in July, the minimum daily displacement of11th students’ dormitory building is8.1m3and32.5m3of the later; highest daily emissions with the highest average daily displacement105.3m3of the former is in May and, while the highest daily emissions of17th students’ dormitory is in September, with135.6m3of theaverage maximum daily displacement.(4) Seasonal variation of the sewage emissionThe seasonal average minimum daily emissions (37.2m3) of11thstudents’ dormitory building appears in the summer, however the average highest daily emissions (101.6m3) appears is in the spring. While the average minimum daily emissions (56m3)of17thstudents’ dormitory building appears in winter, however the daily highest emissions (115.2m3)is in the autumn season.(5)Term variation of the sewage emissionThe average daily emissions (81.6m3) of11th students’ dormitory building can be seen in the spring semester, and the number decreases to76m3in thefall semester; such numbers are a little different in17thstudents’ dormitory building with92.5m3and89.4m3respectively.2) Water quality analysis of sewageThe concentrations of CODCr, NH3-N, TN and TP of sewage from the girls’ dormitory building (17thstudents’ dormitory building) were higher from1:00a.m.to6:00a.m. zhan other time, and lowest around10:00p.m. in one day. There were little change of concentrations of CODCr, NH3-N, TN and TP from Mongday to Friday, but concentrations of CODCr, NH3-N, TN and TPat the weekend is slightly lower.2. Treatment effects of sewage from student dormitory building by anaerobic and constructed wetland ecosystemwhen the septic tank is operated stably, COD, NH3-N, TPand SS in the sewage are removed by anaerobic system forthe removal rate are37%,45%,7%and14%respectively.Theremoval rateof COD,NH3-N of sewage from anaerobic treatment system reached73.3%,80.1%respectively by constructed wetland system with Juncus effusus after9day treatment;and the removal rate of chrysanthemum reached44%by constructed wetland system with Wilsonii after9day treatment. |
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