低碳源高氨氮废水中好氧颗粒污泥的培养及特性研究

发布时间：2018-10-12 09:10

【摘要】：好氧颗粒污泥具有密实的结构、好的沉降性能和高的生物量,且对高强度废水、冲击负荷以及有毒物质具有很强的抵抗能力。因此,如何将好氧颗粒污泥系统运用到实际废水处理中的研究,得到了越来越研究者的关注。然而,在实际废水中,进水碳氮比(COD/N)是一个不断变化的参数,特别是垃圾渗滤液、污泥消化液等高氨氮废水,碳氮比例严重失调。过低的COD/N环境会改变好氧颗粒污泥的理化性质和微生物群落结构,是造成颗粒污泥破裂的一个重要原因。本文以普通絮状污泥为接种污泥,在进水COD/N(400/100)为4的条件下培养好氧颗粒污泥；考察COD/N的变化(400/200～600/300)对颗粒污泥理化性质和微生物群落的影响；并对低COD/N(400/100)条件下形成的颗粒污泥的长期运行稳定性进行探究。结果表明：(1)在低COD/N(400/100)条件下,好氧颗粒污泥成功形成。经过近140天的培养,A、B反应器中污泥浓度分别达到4.94g/L和5.36g/L,污泥SVI30/SVI5保持为1。形成的颗粒污泥具有很强的脱碳除氮能力,其中COD的去除率保持在90%以上,氨氮去除率接近100%。(2)进水COD/N由400/100降为400/200后,并未对颗粒污泥的硝化性能和物理特性产生不利影响。保持COD不变的情况下提升进水氨氮浓度至200mg/L,经短暂适应后,系统污泥浓度快速上升,经过110多天的运行,MLSS达到11.38g/L,而污泥SVI30/SVI5始终保持为1,氨氮去除率达到98%；继续调整COD/N至600/300,颗粒污泥的物理特性出现了波动,系统硝化性能发生恶化。在保持COD/N为2的情况下继续提升进水氨氮浓度至300 mg/L,污泥浓度和SVI30/SVI5出现了波动,但MLSS仍保持在9.82g/L以上,污泥SVI30为50 mL/g左右,出水氨氮浓度升高,并在实验结束时,氨氮去除率仅为34.88%。导致系统硝化性能下降的原因可能是颗粒污泥的内部更新和低温影响的结果。(3)不同COD/N条件下的DGGE表明,好氧颗粒污泥中的优势菌为具有稳定颗粒结构并参与脱碳除氮的异养菌；FISH实验发现好氧颗粒污泥中有硝化菌的存在,主要分布在距颗粒污泥外表面约50～100 u m的颗粒内部。(4)低COD/N (400/100)条件下形成的好氧颗粒污泥具有很强的自愈能力。在实验运行期间,好氧颗粒污泥首先发生了破裂随后又自我恢复。然而,好氧颗粒污泥的硝化效率并未受到影响,污泥的浓度和沉降性能虽然下降但又随着系统的恢复而提高。在系统恢复过程中具有稳定颗粒结构的Sphingomonas spp.逐渐成为颗粒中的优势菌。
[Abstract]:Aerobic granular sludge has a dense structure, good settling performance and high biomass, and has a strong resistance to high strength wastewater, shock load and toxic substances. Therefore, how to apply aerobic granular sludge system to practical wastewater treatment has been paid more and more attention by researchers. However, in the actual wastewater, the influent carbon to nitrogen ratio (COD/N) is a constantly changing parameter, especially the landfill leachate, sludge digestion liquid and other high ammonia nitrogen wastewater, the carbon to nitrogen ratio is seriously out of balance. Too low COD/N environment will change the physical and chemical properties of aerobic granular sludge and microbial community structure, which is an important cause of granular sludge rupture. In this paper, aerobic granular sludge was cultured under the condition of COD/N (400 / 100) = 4, and the effects of COD/N (400 / 200 / 600 / 300) on the physicochemical properties and microbial community of granular sludge were investigated. The long-term operation stability of granular sludge formed at low COD/N (400 / 100) was investigated. The results showed that: (1) aerobic granular sludge was successfully formed at low COD/N (400 / 100). After nearly 140 days of culture, the sludge concentration in AZB reactor reached 4.94g/L and 5.36 g / L, respectively, and the sludge SVI30/SVI5 was kept at 1. The formed granular sludge has strong decarbonization and nitrogen removal ability, in which the removal rate of COD is above 90%, and the removal rate of ammonia nitrogen is close to 100. (2) after the influent COD/N is reduced from 400 / 100 to 400 / 200, it has no adverse effect on the nitrification performance and physical characteristics of granular sludge. Under the condition of keeping COD unchanged, the influent ammonia nitrogen concentration was raised to 200mg / L. After a brief adaptation, the sludge concentration of the system increased rapidly. After more than 110 days of operation, the MLSS reached 11.38 g / L, while the sludge SVI30/SVI5 remained at 1, and the ammonia nitrogen removal rate reached 98. When COD/N was adjusted to 600 / 300, the physical properties of granular sludge fluctuated and the nitrification performance of the system deteriorated. Under the condition that COD/N was kept at 2, the influent ammonia nitrogen concentration increased to 300 mg/L, sludge concentration and SVI30/SVI5 fluctuated, but MLSS remained above 9.82g/L, sludge SVI30 was about 50 mL/g, effluent ammonia nitrogen concentration increased, and at the end of the experiment, The removal rate of ammonia nitrogen is only 34.88%. The results of internal regeneration and low temperature effect of granular sludge may be the cause of the decline of nitrification performance. (3) DGGE under different COD/N conditions showed that the dominant bacteria in aerobic granular sludge were heterotrophic bacteria with stable granular structure and involved in decarbonization and nitrogen removal; FISH test showed that nitrifying bacteria existed in aerobic granular sludge, mainly distributed in the inner of granules about 50 ~ 100u m from the outer surface of granular sludge. (4) aerobic granular sludge formed at low COD/N (400 / 100) had strong self-healing ability. During the experimental operation, aerobic granular sludge first ruptured and then recovered. However, the nitrification efficiency of aerobic granular sludge was not affected. The concentration and settling performance of aerobic granular sludge decreased but increased with the restoration of the system. Sphingomonas spp. with stable Particle structure during system recovery Gradually become the dominant bacteria in the granules.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X703

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