低强度超声促进单级自养脱氮工艺处理氨氮废水

发布时间：2018-05-03 19:38

本文选题：单级自养脱氮工艺 + 超声能量　；参考：《大连理工大学》2015年硕士论文

【摘要】：单级自养脱氮工艺具有工艺流程短、运行费用低等优点,但由于功能菌群生长缓慢且易流失继而影响脱氮效率。为改善不足,提高该工艺效率,本论文研究低强度超声对单级自养脱氮工艺的影响,并将其应用于生物膜反应器,颗粒污泥反应器和共包埋反应器三种不同形式的单级自养脱氮工艺中,寻找低强度超声和该工艺的最佳结合方式。首先利用低强度超声对短程硝化反应进行强化。实验保持污泥浓度恒定,不断增加超声能量,发现在43.20 kJ时,亚硝酸菌活性最高,反应速率提高25.44%；在此超声能量条件下,随着亚硝酸菌的污泥浓度从0.34 gVSS/L增加到1.03gVSS/L(即超声能量密度从127.06 kJ/gVSS降低到41.94 kJ/gVSS),氨氧化速率呈现不断上升的趋势,但是继续增加生物量,亚硝酸菌的氨氧化速率开始降低。因此,强化亚硝酸菌的最佳超声能量密度为41.94 kJ/gVSS。进一步探索超声辐射对生物活性影响的机理,结果表明：在最佳超声能量密度下,亚硝酸菌的多糖、蛋白质和胞外聚合物浓度分别提高18.32%,26.54%和22.05%,短程硝化反应过程中关键酶——氨单加氧酶活性也增加36.94%。其次对厌氧氨氧化菌进行低强度超声强化实验。保持污泥浓度恒定,改变超声能量；当超声能量为43.20 kJ时,总氮去除速率最大；在此超声能量下,随着污泥浓度由3.75 gVSS/L减少至1.19gVSS/L(即能量密度则从11.52 kJ/gVSS增加到34.56 kJ/gVSS)总氮去除率不断增加,但继续增加污泥浓度,反应速率下降。若按一定比例同时提高或减少污泥浓度和超声能量(即始终保持最佳能量密度为34.56 kJ/gVSS),则实验组菌群的总氮去除速率基本相似,高于对照组约14.06%。对厌氧氨氧化反应中关键酶——肼脱氢酶(HDH)活性进行考察,发现经过43.20 kJ超声处理(能量密度为34.56 kJ/gVSS)的厌氧氨氧化菌其HDH活性增加15.46%；而直接对HDH进行超声能量为28.80 kJ处理后,其活性提高40.58%。实验证明低强度超声是促进酶活反应而提高污泥脱氮速率。基于上述研究结果,通过连续运行反应器实验考察低强度超声对单级自养脱氮工艺的长效促进作用。反应器运行337天,第1-177天启动三个反应器用于功能菌的培养；第178-270天为稳定运行阶段,实验结果表明：生物膜反应器、共包埋反应器和颗粒污泥反应器总氮去除率分别为58.94%,55.90%和45.05%,其中生物膜反应器脱氮性能最佳；第271-337天对三个反应器施以超声辐射,生物膜反应器和颗粒污泥反应器脱氮效率分别提高33.88%和22.18%,而共包埋反应器无明显提高。实验结果证明低强度超声能有效强化单级自养脱氮工艺的脱氮效率,显著提高自养脱氮生物膜反应器脱氮效率。
[Abstract]:Single stage autotrophic denitrification process has the advantages of short process flow and low operating cost, but the efficiency of denitrification is affected by slow growth of functional flora and easy loss of nitrogen removal. In order to improve the efficiency of this process, the effect of low intensity ultrasound on single stage autotrophic denitrification was studied and applied to biofilm reactor. In three different single-stage autotrophic denitrification processes of granular sludge reactor and co-embedded reactor, the best combination of low-intensity ultrasound and this process was found. First, the short-cut nitrification was strengthened by low-intensity ultrasound. The experiment kept the sludge concentration constant and continuously increased the ultrasonic energy. It was found that the activity of nitrite bacteria was the highest and the reaction rate increased 25.44% at 43.20 kJ. With the increase of sludge concentration from 0.34 gVSS/L to 1.03gVSS / L (that is, the ultrasonic energy density decreased from 127.06 kJ/gVSS to 41.94 kJ / g VSSN), the ammonia oxidation rate showed an increasing trend, but continued to increase the biomass, the ammonia oxidation rate of nitrite bacteria began to decrease. Therefore, the optimum ultrasonic energy density of the enhanced nitrite bacteria is 41.94 kJ / g VSSs. The effects of ultrasonic radiation on biological activity were further explored. The results showed that under the optimum ultrasonic energy density, the polysaccharide of nitrite bacteria, The concentration of protein and extracellular polymer increased by 18.32% and 22.05%, respectively, and the activity of ammonia monooxygenase, the key enzyme during short-course nitrification, was also increased by 36.94%. Secondly, the low-intensity ultrasonic enhancement test was carried out on anaerobic ammoniacal oxidizing bacteria. When the ultrasonic energy is 43.20 kJ, the removal rate of total nitrogen is the highest. As sludge concentration decreased from 3.75 gVSS/L to 1.19 g VSS / L (that is, energy density increased from 11.52 kJ/gVSS to 34.56 KJ / g VSSs), total nitrogen removal rate increased, but the reaction rate decreased with increasing sludge concentration. If the sludge concentration and ultrasonic energy were increased or decreased at the same time (that is, the best energy density was 34.56 KJ / g VSSN), the removal rate of total nitrogen in the experimental group was similar, which was higher than that in the control group about 14.06. The activity of hydrazine dehydrogenase (HDH), a key enzyme in anaerobic ammonia oxidation reaction, was investigated. It was found that the HDH activity of anaerobic ammonia-oxidizing bacteria treated with 43.20 kJ ultrasound (energy density 34.56 kJ / g VSSs) increased 15.46%, while the ultrasonic energy of 28.80 kJ was directly applied to HDH. Its activity was increased by 40.58. It is proved that low intensity ultrasound can promote enzyme activity and increase sludge denitrification rate. Based on the above results, the long effect of low intensity ultrasound on single stage autotrophic denitrification was investigated by continuous running reactor. The results showed that the biofilm reactor was used in the biofilm reactor, and the three reactors were started for the culture of functional bacteria in 337 days and 1 to 177 days, and the stable operation stage was in the 178-270 days. The removal rates of total nitrogen in co-entrapment reactor and granular sludge reactor were 58.94% and 45.05%, respectively, in which biofilm reactor had the best denitrification performance, and ultrasonic radiation was applied to the three reactors on the 271-337 days. The denitrification efficiency of biofilm reactor and granular sludge reactor was increased by 33.88% and 22.18%, respectively, but the co-entrapment reactor did not. The experimental results show that low intensity ultrasound can effectively enhance the denitrification efficiency of single-stage autotrophic denitrification process and significantly improve the denitrification efficiency of autotrophic biofilm reactor.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703.1

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