脱硝微藻筛选及气升圆柱光生物反应器脱硝效能研究

发布时间：2018-06-09 14:10

本文选题：微藻 + 脱硝　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：传统脱硝系统能耗大、基建投资高及一般会产生二次污染等问题,难以达到经济、低耗的要求。微藻在生长代谢过程中吸收和转化NOx,相对于传统物化方法没有催化剂昂贵以及腐蚀的问题,还可同时固碳脱硝,同时藻细胞含有大量高经济价值产品。微藻脱硝技术可以实现废物资源化,也具有经济性,是一种极有潜力的NOx去除方案。该技术中高效的脱硝藻种和反应器是关键,因此本论文主要针对脱硝藻种的筛选、藻种脱硝性质和脱硝反应器的构型和脱氮效率开展研究。筛选出一株烟道气高耐性藻种,鉴定该藻为一株微芒藻(Micractinium sp.),该藻对100ppm NO的去除率达90%,生长速率0.14111g L d????。加入100ppm SO2后,微藻生长明显受到抑制,证实SO2的加入致使p H等环境发生改变,不利于微藻的生长。以10%CO2作为碳源,微藻生长慢于葡萄糖组,并导致总脱硝效率的下降。以NO作为氮源培养微藻,微藻生长快于以NO3-N组,但并不能增加藻干重,说明NO相比较于NO3-N,能促使微藻提前成熟。考察了不同进气条件下气升平板、膜式平板、气升圆柱、膜式圆柱四种反应器中微藻生长状况以及对污染物去除效果。通空气情况下,气升和膜式圆柱PBR中藻干重分别达到1.0g/L和0.95g/L,是气升和膜式平板PBR中藻干重的1.82倍和1.77倍。通入10%CO2明显改善了微藻的生长条件,气升和膜式圆柱PBR中藻干重分别达到了1.50g/L和1.45g/L,是气升和膜式平板PBR的1.50倍和1.45倍。本实验条件下,气升圆柱PBR能达到最好的传质和培养微藻效能。系统研究了气升圆柱PBR对微藻脱硝效能的影响,建立了微藻脱硝模型,重点对微藻的培养方式、进气NO浓度、初始液相氮浓度、反应器不同高径比等进行了研究。光异养方式下微藻的生长速率是混养的1.5倍,累计NO去除率为96.51%。同样在光异养方式下微芒藻对NO3-N有较高的去除率。在100,300,500ppm浓度下微藻对NO的去除率分别为96.51%、91.99%和88.57%,藻干重分别为1.448、1.428和0.924 g/L,对照组为1.42 g/L,证实NO对微藻存在“低浓度促进、高浓度抑制”的作用。当培养基中初始NO3-N的浓度分别为17.65mmol/L、35.3mmol/L、88.25mmol/L和176.5mmol/L时,微藻对NO3-N的去除率分别为39.12%、17.85%、27%和11%,即高浓度NO3-N会抑制微藻的生长。高径比15的反应器中微藻生长速率是高径比1.1的1.37倍,累计去除率分别为96.51%和97.02%。高径比15的反应器中微藻对NO3-N的利用率为39.97%,稍大于高径比1.1组的36.84%。
[Abstract]:The traditional denitrification system has many problems, such as high energy consumption, high investment in capital construction and secondary pollution, so it is difficult to meet the requirements of economy and low consumption. Compared with the traditional physicochemical methods, microalgae absorb and transform no _ x in the growth and metabolism process. Compared with the traditional physical and chemical methods, it has no problems of expensive catalyst and corrosion. It can also sequester and denitrification at the same time, and the algal cells contain a large number of high-value products. Microalgae denitrification is a potential NOx removal scheme because it can realize waste recycling and is economical. The key of this technology is the efficient denitrification algae seed and reactor, so this paper mainly focuses on the screening of denitrification algae species, the properties of denitrification, the configuration and denitrification efficiency of denitrification reactor. A high tolerance algal strain was selected and identified as Micractinium sp. the algae was identified as Micractinium sp. the removal rate of 100ppm no was 90% and the growth rate was 0. 14111 g / d ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1). After the addition of 100ppm SO2, the growth of microalgae was obviously inhibited. It was proved that the addition of SO2 caused changes in pH and other environments, which was not conducive to the growth of microalgae. Using 10 carbon dioxide as carbon source, the growth of microalgae was slower than that of glucose group, and the total denitrification efficiency decreased. Microalgae cultured with no as nitrogen source grew faster than those treated with no _ 3-N, but could not increase the dry weight of algae, indicating that no could accelerate the maturation of microalgae compared with no _ 3-N. The growth of microalgae and the removal efficiency of pollutants were investigated in four kinds of reactors, I. e., air lift plate, membrane plate, air lift cylinder and membrane cylinder under different air intake conditions. The dry weight of algae in air-lift and membrane cylindrical PBR was 1.0g / L and 0.95g / L respectively, which was 1.82 and 1.77 times of that in air-lift and membrane PBR respectively. The dry weight of algae in air-lift and membrane-type cylindrical PBR was 1.50 g / L and 1.45 g / L respectively, which was 1.50 and 1.45 times as much as that of air-lift and membrane PBR, respectively. In this experiment, PBR can achieve the best mass transfer and microalgae culture efficiency. The effects of air-lift cylinder PBR on denitrification efficiency of microalgae were systematically studied, and the model of denitrification of microalgae was established. The culture mode of microalgae, the concentration of no in inlet air, the initial concentration of liquid nitrogen and the ratio of height to diameter of reactor were studied. The growth rate of microalgae in photoheterotrophic mode was 1.5 times of that of mixed culture, and the cumulative no removal rate was 96.51 kum. The removal rate of no _ 3-N was also higher under the light heterotrophic mode. The removal rates of no by microalgae at 100300500ppm concentration were 91.99% and 88.57, respectively. The dry weight of algae was 1.448% and 0.924 g / L, respectively, and that of control group was 1.42 g / L. it was proved that no had the effect of "promoting low concentration and high concentration inhibition" on microalgae. When the initial concentration of NO3-N was 17.65 mmol / L 35.3 mmol / L and 176.5 mmol / L, respectively, the removal rates of NO3-N in microalgae were 39.12% and 17.85%, respectively. The high concentration of NO3-N inhibited the growth of microalgae. The growth rate of microalgae in the reactor with the ratio of height to diameter 15 was 1.37 times of that of the ratio of height to diameter 1.1, and the cumulative removal rates were 96.51% and 97.02%, respectively. The utilization rate of NO3-N in the reactor with height to diameter ratio 15 was 39.97, which was slightly higher than that in the height to diameter ratio 1.1 group (36.84).
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X701;X173

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