曝气条件下微生物强化砾石河床改善河水水质试验研究

发布时间：2018-07-02 21:02

  本文选题：黑臭河道 + 曝气复氧　； 参考：《东南大学》2016年硕士论文

【摘要】：传统河道曝气技术能在短时间内提高水体溶解氧浓度、消除河道黑臭状态,在河道水质改善方面具有一定的可行性和优越性。本文尝试将投加微生物工程菌、砾间接触氧化法与河道曝气技术有机结合,研发长期效果更好的组合工艺。主要研究内容及结论如下：(1)0.33m3/m2·h、1.66m3/m2·h、3.33m3/m2·h三种曝气强度的比较表明,曝气强度大水质改善效果更显著,考虑到经济成本后选择的曝气量为1.66m3/m2·h。该曝气强度下,78h连续曝气后CODMn、NH3-N分别从16.6mg/L、11.8 mg/L降低到11.2mg/L和8.37mg/L：综合比较水质改善效果和经济性后,确定工程菌投加量为500mL/t,投加7d后CODMn、NH3-N分别从18.2 mg/L、8.03 mg/L下降到10.1 mg/L和5.69 mg/L;而间歇曝气条件下投加工程菌,7d后CODMn、NH3-N 从17.3 mg/L、8.29 mg/L下降至6.6 mg/L和5.63 mg/L。(2)投加工程菌挂膜后,30cm、50cm、80cm三种高度砾石床的比较表明,砾石填料越高水质改善效果越好。80cm厚砾石填料,静水7d后CODMn、NH3-N从18.6mg/L、9.37mg/L下降到10.3mg/L、6.09mg/L; 0.5m/h、0.25m/h、0.125m/h三种不同流速比较表明,流速慢时效果更好,曝气条件下工程菌强化砾石河床的工艺适用于缓流水体,流速为0.125m/h时,CODMn、NH3-N从17.8mg/L、8.77mg/L分别下降到11.9mg/L和6.88mg/L。(3)模拟河道的连续运行结果表明：一次投加工程菌种砾石(50em)挂膜成功后,水流流速0.125m/h、每天曝气2h,水质改善效果可至少维持25天,CODMn、NH3-N去除率为27.3%-47%和10.9%～33.4%。低温条件下(最低气温.3℃-8℃),各种措施的效果都有下降,单纯曝气对CODMn和NH3-N的去除率都为约20%,投加工程菌对CODMn几乎没有效果,而对NH3-N仍有25%的去除率,曝气加工程菌对CODMn、NH3-N去除率约40%和30%,而投加工程菌挂膜后的砾石床对CODMn、NH3-N的去除率仅有约10%。(4)以宜兴市和桥镇的公园河为例,按照砾石河床(50cm)、间歇曝气(2h/d)、投加工程菌(一次性投加500mL/t)的组合工艺,进行了工程设计计算,总需氧量为7.6kgO2/d,工程投资约9.2万元、运行费用为73.08元/d,同类型河道的修复工程投资费用为80万元/km、运行费为635元／(d·km)。
[Abstract]:The traditional aeration technology can improve the dissolved oxygen concentration in the water in a short time, eliminate the black-smelling state of the river, and have certain feasibility and superiority in improving the water quality of the river. This paper attempts to develop a better long-term effect combination process by adding microbial engineering bacteria, contact oxidation between gravel and river aeration technology. The main research contents and conclusions are as follows: (1) the comparison of three aeration intensities of 1.66m3mm3 / m2h and 3.33m3m2h shows that the effect of improving water quality with high aeration intensity is more remarkable, and the aeration rate chosen after considering the economic cost is 1.66m3/m2 h. After continuous aeration for 78 h, the NH3-N of CODMnn decreased from 16.6 mg / L to 11.8mg / L to 11.2 mg / L and 8.37 mg / L, respectively. It was determined that the dosage of engineering bacteria was 500mL / t, and the NH3-N of CODMnn decreased from 18.2 mg / L 8.03 mg / L to 10.1 mg / L and 5.69 mg / L respectively after 7 days of addition, while after 7 days of intermittent aeration, CODMnNH3-N decreased from 17.3 mg / L to 6.6 mg / L and 5.63 mg / L respectively. (2) the three heights of CODMnNH3-N were decreased from 17.3 mg / L to 6.6 mg / L and 5.63 mg / L respectively. (2) the three heights of CODMnNH3-N were decreased from 17.3 mg / L to 6.6 mg / L and 5.63 mg / L respectively under intermittent aeration. A comparison of gravel beds shows that The higher the gravel packing, the better the effect of improving the water quality. The better. 80 cm thick gravel packing. After 7 days of static water, the NH3-N of CODMnn decreased from 18.6 mg / L 9.37 mg / L to 10.3 mg / L 6.09 mg / L; 0.5 mg / h 0.25 m / h / 0.125 m/ h; three different flow rates showed that the effect was better when the flow rate was slow. Under aeration condition, the process of strengthening gravel bed by engineering bacteria is suitable for the slow flow water. When the flow rate is 0.125m/h, the NH3-N of CODMnN decreases from 17.8mg / L to 11.9mg / L and 6.88mg / L respectively. When the flow velocity is 0.125 m / h and aeration is 2 h per day, the effect of water quality improvement can be maintained for at least 25 days. The removal rate of NH3-N of CODMnU is 27.3- 47% and 10.9% respectively. At low temperature (minimum temperature of 3 鈩，

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