Study on the Self-purification in Chenhang Reservoir of Shanghai
|Keywords||Chenhang Reservoir Hydrodynamic model Water quality model Hydraulic retention time Water quality parameters Self-purification law Reservoir optimal operation|
This paper proposes the necessity and significance of research of Shanghai Chenhang reservoir of self-purification laws, summed up the domestic and international lakes, reservoirs contaminant migration and transformation of research progress; particular, nitrogen, phosphorus, migration and transformation of E. coli and its water quality models; Here actual water quality status quo based on the combination Chenhang Reservoir proposed research methods: laboratory water quality parameters, the site's main water quality parameters and water environment mathematical model combining self-purification research Chenhang Reservoir pollutants law. The main findings and conclusions: 1. In lab studies, the carbonation the BOD degradation coefficient changes range 0.2 ~ 1.2d -1 sup>; nitrification BOD degradation coefficient range 0.17 to 1.8d of -1 sup>. 2. Sediment release experiments show that: ammonia release from sediments flux range: 4 ~ 18mg / m 2 sup>-d; sediment total nitrogen release flux range: 20 to 50mg / m sup>-d, Phosphate release flux range: 3 ~ 10mg / m 2 sup>-d. Chen line the water She ammonia release the flux equivalent Taihu (Wulihu Lake) release flux from 3% to 11%. 3.6 month Chenhang Reservoir water quality overall is better, but the total nitrogen, total phosphorus exceeded; reservoir water quality evaluation results show that the reservoir in 60 to 80% of SS removal; Obviously Total Coliforms removal, removal rate of 80%; total phosphorus removal rate of 30% to 70% of the total nitrogen removal rate is 40.8%. 4. Application of the WIN / DYNHYD Chen Reservoir hydrodynamic model; major affect reservoir flow Chenhang field factors as wind direction, wind speed, and reservoir and out of traffic changes; water level varies with the flow rate change, part of the Chenhang Reservoir reflux generate flow rate is small, in the range of 0 ~ 0.07m / s. 5. Completely mixed model Chen Hang Reservoir the ammonia degradation of the law, the results showed that: as Chenhang reservoir storage capacity increases, the hydraulic retention time of the reservoir corresponding variable length, ammonia removal efficiency also increased. 6. Application WASP6 model, Chen Reservoir water quality model calibration and verification of water quality parameters: water quality model results show that: the main factors affect the the reservoir waters Chenhang pollutant removal is the water temperature, storage capacity, and residence time. Water temperature is high (about 25 ° C), large storage capacity, hydraulic retention time, the self-purification capacity of the reservoir. In addition, sediment deposition can increase the self-purification capacity of Chenhang Reservoir. 7. Based on the the water eutrophication evaluation criteria, Chenhang Reservoir TN and COD Cr higher concentration, but because of the reservoir HRT shorter, insufficient light, water does not occur due to the individual indicators exceeded the algal blooms polluted water body phenomenon. Based on the above findings, proposed Chenhang reservoir optimal operation management recommendations: avoid sewage running a residence time of the water regulation and seal any l (10 days) and the implementation of the influent pretreatment measures.