巢湖市环城河底泥释放特性研究及补水优化计算

发布时间：2018-07-06 15:58

本文选题：河流水质模型 + 补水流量　；参考：《安徽建筑大学》2015年硕士论文

【摘要】：巢湖市地处安徽中部,临近长江,环抱巢湖。近年来,巢湖市经济迅速发展,巢湖市周围的河流、湖泊均受到不同程度的污染,尤其以巢湖市区的河道污染最为严重,影响居民的日常生活,因此,需要对巢湖市区水环境进行保护和生态安全维护。本课题研究对象环城河为巢湖市区典型污染河流,是巢湖市区最主要水系。环城河分为东、西两部分。东、西环城河水质均为劣V类,水质污染严重,总磷、总氮严重超标。课题根据河道的特征、污染负荷,以COD代替BOD,利用Dobbins-Camp水质模型,计算河道末端水质达标所需要的最小补水流速和最小补水流量,从而优化巢湖市城区水系补水调控技术。选择在东、西环城河上各布置三个采样点,共六个采样点。参照BOD培养法测定COD降解系数k1和沉淀系数k3,并对COD降解系数k1进行修正,得出相同温度下东环城成河COD降解系数比西环城河大,原因是东环城河河水污染程度比西环城河严重,水中污染物较多,导致河流耗氧速度变快,引起COD降解系数k1较大通过底泥耗氧实验模拟测定得到底泥耗氧量AO与时间t呈线性关系,关系式分别为：东环城河7℃时△O=0.0740t+0.4394,15℃时△O=0.1602t-0.1534,28℃时△O=0.2316t,西环城河7℃时△O=0.0899t+0.3661,15℃时△O=0.1522t+0.2651,28℃时△O=0.2088t+0.4600；单位面积单位时间底泥耗氧速率p1与温度T存在线性关系,且水温13℃、29℃、16℃、5℃条件下东环城河单位面积单位时间底泥消耗溶解氧量分别为：17.255mg/(m2·h)、31.857mg/(m2·h)、19.993mg/(m2·h)、9.955mg/(m2·h)水温13℃、29℃、16℃、5℃条件下西环城河单位面积单位时间底泥消耗溶解氧量分别为。17.986mg/(m2·h)、29.956mg/(m2·h)、20.230mg/(m2·h)、12.001mg/(m2·h)。水体复氧包括大气复氧和光合作用复氧。本文采用公式估算法。根据东、西环城河平均水深,选用Churchill公式计算大气复氧系数k2。光合作用复氧特性研究采用黑白瓶实验测定,春季和秋季光照强度相近可视为相同,测定结果分别为：东环城河夏季产氧速率为1.237mg/L·d、耗氧速率为0.303mg/L·d,秋季产氧速率为0.723mg/L·d、耗氧速率为0.273mg/L·d,冬季产氧速率为0.573mg/L·d、耗氧速率为0.283mg/L·d；西环城河夏季产氧速率为0.850mg/L·d、耗氧速率为0.223mg/L·d,秋季产氧速率为0.715mg/L·d、耗氧速率为0.195mg/L·d,冬季产氧速率为0.353mg/L·d、耗氧速率为0.168mg/L·d。通过对底泥释放实验厌氧条件下和自然水体条件下的静态模拟,得出：COD释放量20℃30℃5℃,原因是20℃既不利于微生物降解有机物也不利于矿物质吸附有机物,导致大量有机物释放到水体,水体COD浓度高；底泥释放TN、TP的量是30℃20℃5℃,原因为温度升高,微生物能够利用水中溶解氧降解有机氮和有机磷,此外,溶解氧的减少使得氧化还原电位降低,使Fe3+还原成Fe2+,磷可以从沉淀物中释放出来,所以,温度越高,底泥释放TN、TP越多；厌氧条件下底泥释放COD、TN、TP浓度均大于自然水体条件下底泥释放量,原因是厌氧条件下,好氧微生物不能降解有机物,有机物进行厌氧分解不利于硝化作用和反硝化作用,溶解氧减少容易发生Fe3+还原成Fe2+,因此,COD、TN、TP释放量增多。计算保障河道末端DO≥3mg/L、COD≤30mg/L(Ⅳ类)补水所需要的最小流速分别为：东环城河春季0.0063m/s、夏季0.0136m/s、秋季0.0070m/s、冬季0.0035m/s；西环城河春季0.0155m/s、夏季0.0220m/s、秋季0.0163m/s、冬季0.0055m/s；再根据Q=A×u计算需要的最小补水流量分别为东环城河春季0.2232m3/s、夏季0.4896m3/s、秋季0.2520m3/s、冬季0.1260m3/s；西环城河春季1.3175m3/s、夏季1.8700m3/s、秋季1.3855m3/s、冬季0.4675m3/s。
[Abstract]:Chaohu is located in the middle of Anhui, near the Yangtze River and embracing Chaohu. In recent years, the economy of Chaohu has developed rapidly, and the rivers and lakes around Chaohu are polluted to varying degrees. Especially, the river pollution in the Chaohu city is the most serious and affects the daily life of the residents. Therefore, the water environment of Chaohu city needs to be protected and ecological security needs to be carried out. The research object around the city is the typical polluted river in Chaohu City, which is the most important water system in the city of Chaohu. The city of the city is divided into two parts in the East and West. The water quality of the East and west ring city is V, the water quality is seriously polluted, the total phosphorus and total nitrogen exceed the standard. The project is based on the characteristics of the river, the pollution load, the COD instead of BOD, and the water quality model of the Dobbins-Camp. The minimum water supplement flow rate and the minimum water supplement flow required for the water quality standard of the end of the river channel were calculated to optimize the water supplement control technology in Chaohu city. Three sampling points were arranged on the East and west ring city river, and six sampling points were arranged. The COD degradation coefficient K1 and the precipitation coefficient K3 were measured with reference to the BOD culture method, and the COD degradation coefficient K1 was repaired. At the same temperature, the degradation coefficient of COD in the east ring River is larger than that of the west ring city river. The reason is that the pollution degree of the river water in the east ring River is more serious than that of the west ring city river, and the pollutants in the water are more, causing the speed of the river oxygen consumption to be faster and the COD degradation coefficient K1 is larger through the experimental model of sediment oxygen consumption. The mud oxygen consumption AO is in linear relation with the time t. The relationship is: Delta O=0.0740t+0.4394,15 C at 7 degrees C, Delta O=0.1602t-0.1534,28 C delta O=0.2316t, Delta O=0.0899t+0.3661,15 C at Delta O=0.0899t+0.3661,15 C delta O=0.1522t+0.2651,28 C delta O=0.1522t+0.2651,28 C, Delta O=0.2088t+0.4600 at the time delta O=0.1522t+0.2651,28 C; and there is a linear relationship between the oxygen consumption rate P1 per unit area per unit time and temperature T, and the water temperature is 13, 2. At 9, 16, and 5 C, the amount of dissolved oxygen per unit time per unit area of the east ring city river is 17.255mg/ (m2. H), 31.857mg/ (m2. H), 19.993mg/ (m2. H), 9.955mg/ (M2 h) water temperature 13, 29, 16, 5, respectively. H), 20.230mg/ (m2. H), 12.001mg/ (m2. H). Water reoxygenation includes atmospheric reoxygenation and photosynthesis reoxygenation. The formula estimation method is used in this paper. According to the average water depth of the East and west ring city river, the re oxygen characteristic of the atmospheric reoxygenation coefficient k2. photosynthesis is calculated by the Churchill formula, and the experimental determination of the black and white bottle is used for the study. The light intensity of the spring and autumn is similar to that of the autumn. The results are as follows: the oxygen rate of the east ring River is 1.237mg/L D, the oxygen consumption rate is 0.303mg/L D, the oxygen rate is 0.723mg/L D, the oxygen consumption rate is 0.273mg/L D, the oxygen rate is 0.573mg/L D in winter, the oxygen consumption rate is 0.283mg/L D, and the oxygen rate of the West ring city river in summer is 0.22. 3mg/L. D, the oxygen rate in autumn is 0.715mg/L. D, oxygen consumption rate is 0.195mg/L. D, oxygen rate is 0.353mg/L D in winter, oxygen consumption rate is 0.168mg/L. D. through the static simulation under the experimental anaerobic condition and natural water condition under the sediment release, the COD release amount is 20 C 30 C 5 C, the reason is that 20 C is not good for microbial degradation organic. It is also not conducive to mineral adsorption of organic matter, resulting in a large number of organic substances released into the water body, the concentration of COD in water body is high, sediment release TN, the amount of TP is 30 degrees centigrade 20 degrees centigrade, the reason for the increase of temperature, microorganism can use dissolved oxygen in water to degrade organic nitrogen and organophosphorus, in addition, the reduction of dissolved oxygen reduces the oxidation-reduction potential and makes Fe3+ reduced to Fe 2+, phosphorus can be released from the sediment, so the higher the temperature, the more the sediment release TN, the more TP, the release of COD, TN and TP under anaerobic conditions is greater than the release of sediment under the natural water condition. The reason is that aerobic microorganisms can not degrade organic matter under anaerobic conditions. The anaerobic decomposition of organic compounds is not conducive to nitrification and anti nitrification. As a result, the reduction of dissolved oxygen is easily reduced to Fe2+, so the release of COD, TN and TP is increased. The minimum flow rate to ensure DO more than 3mg/L at the end of the river and the minimum flow rate required for COD less than 30mg/L (class IV) water supplement are: the spring 0.0063m/s of the east ring River, the 0.0136m/s in summer, the autumn 0.0070m, the winter, the spring of the west ring city and the summer season. In autumn 0.0163m/s, winter 0.0055m/s; and then according to the Q=A x u calculation required for the minimum water flow rate is the east ring city spring 0.2232m3/s, summer 0.4896m3/s, autumn 0.2520m3/s, winter 0.1260m3/s; West ring city spring 1.3175m3/s, summer 1.8700m3/s, autumn 1.3855m3/s, the winter 0.4675m3/s..
【学位授予单位】：安徽建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X522

【参考文献】