The Experimental Investigation on the Treatment of Nitrogen and Phosphorus of Domestic Sewage by Integrated Vertical-Flow Constructed Wetland
|School||East China Jiaotong University|
|Course||Road and Railway Engineering|
|Keywords||The Vertical Flow artificial wetlands Sewage Nitrogen and phosphorus removal|
Elaborate of artificial wetlands decontamination mechanism, the existing the main dynamics model, design method, the research status at home and abroad, and artificial wetlands system. Based on geographical differences in the characteristics of the constructed wetland, applied research in the areas of Jiangxi the composite vertical flow constructed wetland treatment of domestic sewage in the benefits of nitrogen, phosphorus and laws. First through the test to determine the best operating conditions of the composite vertical flow constructed wetland, using orthogonal test analysis Vertical Flow Constructed wetland treatment of nitrogen, phosphorus effect influencing factors. Then major influencing factors of multi-level test the influence of nitrogen, phosphorus purifying effect. And the establishment of various pollutants such as nitrogen, phosphorus and hydraulic retention time between the first order kinetics equation. The conclusions of the analysis are as follows: (1) Vertical Flow Constructed wetlands run has a great impact on sewage purifying effect. Canna and windmill grass composite vertical flow wetland systems, hydraulic loading 181.25mm / d under purifying effect of the five conditions of the study. The results show that the running period of six hours, the best conditions for three hours without water 3 hours water purification effect, wetland bed CODcr the NH 3 -N, TN, TP water quality have reached the \sewage treatment plant pollutant discharge standard (GB 18918-2002) \%, 70.54%, 92.5% the windmill grass wetland bed CODcr, NH 3 -N, TN and TP removal rate were 88.6%, 58.1%, 65.84%, 91.6%. (2) orthogonal experiment results show that: the four factors that affect the size of the role of nitrogen and phosphorous as follows: Process gt; the hydraulic loading gt; pH value gt; CODcr affect the role of size of the total nitrogen as follows: Process gt; hydraulic load gt; CODcr gt; pH value. (3) the composite vertical flow constructed wetland system sewage purification effect hydraulic loading has a close relationship with the two sets of wetland bed purifying effect decreases with increasing hydraulic loading. Hydraulic loading 241.5mm / d, two groups of wetland bed effluent pollution indicators were lower than the urban sewage treatment plant pollutant discharge standard (GB 18918-2002) \The NH 3 -N, TN and TP removal rate were 90.0%, 69.6%, 61.67%, 90.9%, windmill grass wetland bed in the hydraulic loading CODcr NH < / sub>-N, TN, TP, 85.3%, 54.8%, 55.92%, 87.78%. The test conclusion analysis showed that composite vertical flow constructed wetland treatment of domestic sewage in the Jiangxi region to achieve good results. (4) the pollution load test studies have shown that, the greater the impact of the pollution load of the composite vertical flow constructed wetland removal loading. CODcr, NH 3 >-N, TN and TP removal load increased with the increase in pollution load increases, and both showed a linear relationship. That composite vertical flow constructed wetlands in the test range of the above four pollutants there are still some upgrade potential, the wetland system can be used to deal with the higher concentration of sewage. (5) sewage wetland system in the process of purifying effect has important implications. CODcr, NH 3 >-N, TN and TP removal rate increased with the increase of flow increases, but rendered the relationship is different. CODcr removal showed a good linear relationship with flow changes in the overall. And the NH 3 -N, TN, TP removal efficiency with a high degree of change in wetlands first half showed a good linear relationship, but 850mm at the inflection point in the process. 1100mm at the two sets of wetland bed effluent pollution indicators have reached the urban sewage treatment plant pollutant discharge standard (GB 18918-2002) \(6) composite vertical flow constructed wetland sewage nitrogen, phosphorus removal law in line with the first-order kinetics relationship Canna wetland bed CODcr NH 3 -N, TN, TP order kinetics model were ln (Ce/C0) =-0.0561t-1.0579, ln (Ce/C0) =-0.0415t-0.1785, ln (Ce/C0) =-0.0214t-0.5403, ln (Ce/C0 ) =-0.0423t-1.2517; windmill grass wetland bed CODcr, NH3-N, TN, TP a dynamic model were ln (Ce/C0) =-0.0424t-1.0724, ln (Ce/C0) =-0.0273t-0.1589, ln (Ce/C0) =-0.0212t-0.4422, ln (Ce/C0) =-0.0295t-1.1265, correlation coefficient R2 were higher than 0.9.