餐廚垃圾發(fā)酵碳源制備及其生物脫氮利用性能研究
發(fā)布時間：2018-07-31 17:07
【摘要】：碳源缺失現(xiàn)象普遍存在并已經(jīng)成為了制約污水處理高效脫氮的重要原因,通過投加碳源強化反硝化過程是提升脫氮效率的重要途徑。餐廚垃圾是城市有機固體廢物的來源之一,本著“以廢治廢”的原則,利用其有機物含量高的特點,從餐廚垃圾制備可用碳源已成為水環(huán)境界關注的技術發(fā)展方向�；诖四康�,本文以校園餐廚垃圾為基質,系統(tǒng)地研究了高溫自由發(fā)酵和中溫乳酸發(fā)酵兩種碳源制備模式的特點,全面考察了發(fā)酵產(chǎn)物作為碳源的反硝化特性,并針對低碳氮比(C/N)生活污水處理和再生利用,開展了A/O-MBR中試研究,重點考察了碳源投加后的脫氮效率和膜污染特性。研究工作的主要成果如下:(1)提出了餐廚垃圾碳源制備的技術策略,將厭氧消化過程控制在水解和酸化階段,以實現(xiàn)可用碳源的高效回收。高溫自由發(fā)酵(55°C,無pH調節(jié))能有效促進有機物水解,產(chǎn)物中以碳水化合物為主;中溫酸性發(fā)酵(37°C,間歇調節(jié)pH至6)有利于酸化過程,能有效富集乳酸菌(Lactobacillus),產(chǎn)物以乳酸為主,并在OLR為14 g-TS/L·d時獲得最大的乳酸產(chǎn)量,較高的OLR不利于乳酸發(fā)酵。(2)研究比較了不同接種對中溫乳酸發(fā)酵碳源制備的影響,發(fā)現(xiàn)以餐廚垃圾本身作為接種時,乳酸產(chǎn)量最大,有機物損失量最少。微生物種群結構分析結果表明,盡管接種液中微生物種群結構差異較大,但在最優(yōu)的發(fā)酵條件下,Lactobacillus能大量富集并成為優(yōu)勢種群,并實現(xiàn)基質高效轉化。(3)研究提出了動態(tài)膜乳酸發(fā)酵強化技術,利用動態(tài)膜對顆粒態(tài)有機物的截留作用,延長了基質在反應器中的停留時間,增大了微生物量,強化了微生物酶活性,進而極大地提高乳酸產(chǎn)量。通過動態(tài)膜乳酸發(fā)酵可實現(xiàn)溶解性發(fā)酵產(chǎn)物的連續(xù)分離,從而提高發(fā)酵碳源制備效率。(4)研究揭示了中溫酸性發(fā)酵條件下,有機物水解酸化過程中呈現(xiàn)的“碳水化合物→乳酸→VFAs”的物質轉化路徑,及其相關的微生物種群結構變化規(guī)律。利用未發(fā)酵、部分發(fā)酵、乳酸為主和VFAs為主的階段產(chǎn)物作為碳源進行反硝化試驗,結果表明,乳酸為主的發(fā)酵產(chǎn)物具有較高的反硝化速率和潛能,并能在C/N比大于6時實現(xiàn)完全反硝化。利用乳酸為主的發(fā)酵產(chǎn)物作為小試SBR碳源用于低C/N比實際污水處理時發(fā)現(xiàn),反應器能夠長期穩(wěn)定運行,脫氮效率明顯提高,微生物的碳源利用能力增強,微生物種群多樣性豐富。(5)高溫自由發(fā)酵產(chǎn)物雖然以碳水化合物為主,但作為外增碳源也具有良好的反硝化促進作用,且發(fā)酵液中未充分水解的顆粒態(tài)有機物也能得到生化利用,實現(xiàn)強化脫氮效果。以高溫自由發(fā)酵產(chǎn)物作為補充碳源用于中試A/O-MBR系統(tǒng)進行低C/N比實際污水處理,結果表明,反應器能夠長期穩(wěn)運行定,微生物的碳源利用能力明顯強化,具有降解溶解性微生物代謝產(chǎn)物(SMP)和復雜有機物能力的微生物種群增多,反硝化菌群相對豐度增加,脫氮效率明顯提高。發(fā)酵產(chǎn)物投加后反應器內微生物胞外聚合物(EPS)并未明顯累積,溶解性有機物(DOM)沿A/O-MBR系統(tǒng)處理流程逐漸降低,部分污染物被膜面泥餅層截留,長期運行過程中并未導致膜面的不可逆污染。
[Abstract]:The loss of carbon source is common and has become an important reason for restricting the efficient denitrification of sewage treatment. Strengthening the denitrification process by adding carbon source is an important way to enhance the efficiency of denitrification. In this paper, the characteristics of two carbon source models for high temperature free fermentation and medium temperature lactic acid fermentation are systematically studied based on the purpose of this purpose. The characteristics of the denitrification characteristics of the fermented products as carbon sources are investigated in this paper. Compared with (C/N) domestic sewage treatment and reuse, the pilot study of A/O-MBR was carried out, and the nitrogen removal efficiency and membrane fouling characteristics after the addition of carbon source were investigated. The main achievements of the research are as follows: (1) the technical strategy of carbon source preparation for food waste is proposed, and the anaerobic digestion process is controlled at the stage of hydrolysis and acidification to achieve the available carbon source. High efficiency recovery. High temperature free fermentation (55 C, no pH regulation) can effectively promote the hydrolysis of organic matter. Carbohydrates are the main products in the products. Medium temperature acid fermentation (37 degree C, intermittent regulation of pH to 6) is beneficial to acidification process and can effectively enrich lactic acid bacteria (Lactobacillus). The products are mainly lactic acid, and the maximum lactic acid yield is obtained when OLR is 14 g-TS/L D. The higher OLR was not beneficial to lactic acid fermentation. (2) the effect of different inoculation on the preparation of carbon source in medium temperature lactic acid fermentation was compared. It was found that the production of lactic acid was the largest and the loss of organic matter was the least. The results of microbial population structure analysis showed that, although the diversity of the microbial population structure in the inoculant was the best, it was the best. Under the condition of fermentation, Lactobacillus can enrich and become the dominant population, and realize the efficient transformation of matrix. (3) the dynamic membrane lactic acid fermentation strengthening technology was put forward, the dynamic membrane was used to intercept the granular organic matter, prolong the residence time of the matrix in the reactor, increase the microbial biomass and strengthen the microbial enzyme activity. The continuous separation of dissolved fermentation products can be achieved by dynamic membrane lactic acid fermentation, and the efficiency of the fermentation carbon source can be improved. (4) the transformation path of "carbohydrate to lactic acid to VFAs" in the process of hydrolysis and acidification of organic matter under the condition of medium temperature acid fermentation, and the phase of its phase, and its phase are revealed. The change rule of the microbial population structure of the microorganism. The denitrification test was carried out by using the unfermented, partially fermented, lactic acid based and VFAs dominant phase products as the carbon source. The results showed that the lactic acid based fermentation products had high denitrification rate and potential, and could complete denitrification when the C/N ratio was greater than 6. The fermentation by lactic acid was the main fermentation. The product was used as a small test SBR carbon source for low C/N ratio to actual sewage treatment. It was found that the reactor can run steadily for a long time, the efficiency of nitrogen removal is obviously improved, the carbon source utilization ability of microorganism is enhanced and the diversity of microbial population is rich. (5) the high temperature free fermentation products are mainly carbon hydrates, but they also have good reaction as the external carbon source. Nitrification promotes the effect, and the granular organic matter which is not fully hydrolyzed in the fermentation broth can also be used for biochemical utilization, and the effect of enhanced denitrification is achieved. The high temperature free fermentation product is used as a supplementary carbon source for the low C/N ratio of the actual wastewater treatment in the pilot A/O-MBR system. The results show that the reactor can run steadily for a long time and the carbon source of microorganism can be used. The increase of microbial population with the ability to degrade dissolved microorganism metabolites (SMP) and complex organic matter increased, the relative abundance of denitrifying bacteria increased and the efficiency of denitrification increased obviously. The microbial extracellular polymer (EPS) in the reactor was not obviously accumulated after the fermentation product was added, and the dissolved organic matter (DOM) was treated along the A/O-MBR system. The process gradually decreased, and some pollutants were trapped by the membrane cake layer. The long-term operation did not lead to irreversible fouling on the membrane surface.
【學位授予單位】：西安建筑科技大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：X799
，
本文編號：2156264
[Abstract]:The loss of carbon source is common and has become an important reason for restricting the efficient denitrification of sewage treatment. Strengthening the denitrification process by adding carbon source is an important way to enhance the efficiency of denitrification. In this paper, the characteristics of two carbon source models for high temperature free fermentation and medium temperature lactic acid fermentation are systematically studied based on the purpose of this purpose. The characteristics of the denitrification characteristics of the fermented products as carbon sources are investigated in this paper. Compared with (C/N) domestic sewage treatment and reuse, the pilot study of A/O-MBR was carried out, and the nitrogen removal efficiency and membrane fouling characteristics after the addition of carbon source were investigated. The main achievements of the research are as follows: (1) the technical strategy of carbon source preparation for food waste is proposed, and the anaerobic digestion process is controlled at the stage of hydrolysis and acidification to achieve the available carbon source. High efficiency recovery. High temperature free fermentation (55 C, no pH regulation) can effectively promote the hydrolysis of organic matter. Carbohydrates are the main products in the products. Medium temperature acid fermentation (37 degree C, intermittent regulation of pH to 6) is beneficial to acidification process and can effectively enrich lactic acid bacteria (Lactobacillus). The products are mainly lactic acid, and the maximum lactic acid yield is obtained when OLR is 14 g-TS/L D. The higher OLR was not beneficial to lactic acid fermentation. (2) the effect of different inoculation on the preparation of carbon source in medium temperature lactic acid fermentation was compared. It was found that the production of lactic acid was the largest and the loss of organic matter was the least. The results of microbial population structure analysis showed that, although the diversity of the microbial population structure in the inoculant was the best, it was the best. Under the condition of fermentation, Lactobacillus can enrich and become the dominant population, and realize the efficient transformation of matrix. (3) the dynamic membrane lactic acid fermentation strengthening technology was put forward, the dynamic membrane was used to intercept the granular organic matter, prolong the residence time of the matrix in the reactor, increase the microbial biomass and strengthen the microbial enzyme activity. The continuous separation of dissolved fermentation products can be achieved by dynamic membrane lactic acid fermentation, and the efficiency of the fermentation carbon source can be improved. (4) the transformation path of "carbohydrate to lactic acid to VFAs" in the process of hydrolysis and acidification of organic matter under the condition of medium temperature acid fermentation, and the phase of its phase, and its phase are revealed. The change rule of the microbial population structure of the microorganism. The denitrification test was carried out by using the unfermented, partially fermented, lactic acid based and VFAs dominant phase products as the carbon source. The results showed that the lactic acid based fermentation products had high denitrification rate and potential, and could complete denitrification when the C/N ratio was greater than 6. The fermentation by lactic acid was the main fermentation. The product was used as a small test SBR carbon source for low C/N ratio to actual sewage treatment. It was found that the reactor can run steadily for a long time, the efficiency of nitrogen removal is obviously improved, the carbon source utilization ability of microorganism is enhanced and the diversity of microbial population is rich. (5) the high temperature free fermentation products are mainly carbon hydrates, but they also have good reaction as the external carbon source. Nitrification promotes the effect, and the granular organic matter which is not fully hydrolyzed in the fermentation broth can also be used for biochemical utilization, and the effect of enhanced denitrification is achieved. The high temperature free fermentation product is used as a supplementary carbon source for the low C/N ratio of the actual wastewater treatment in the pilot A/O-MBR system. The results show that the reactor can run steadily for a long time and the carbon source of microorganism can be used. The increase of microbial population with the ability to degrade dissolved microorganism metabolites (SMP) and complex organic matter increased, the relative abundance of denitrifying bacteria increased and the efficiency of denitrification increased obviously. The microbial extracellular polymer (EPS) in the reactor was not obviously accumulated after the fermentation product was added, and the dissolved organic matter (DOM) was treated along the A/O-MBR system. The process gradually decreased, and some pollutants were trapped by the membrane cake layer. The long-term operation did not lead to irreversible fouling on the membrane surface.
【學位授予單位】：西安建筑科技大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：X799
，
本文編號：2156264
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