規(guī)模化豬場(chǎng)廢水處理系統(tǒng)中氧化塘產(chǎn)甲烷和脫氮微生物學(xué)機(jī)理研究
發(fā)布時(shí)間：2018-08-28 10:26
【摘要】：氧化塘作為一種基建投資少、運(yùn)行管理簡(jiǎn)便、能耗成本較低的污水處理工藝,被廣泛應(yīng)用于規(guī)�；i場(chǎng)厭氧發(fā)酵廢水的處理。然而,伴隨進(jìn)水中高濃度化學(xué)需氧量(COD)和氨氮(NH4+-N)的輸入,氧化塘存在溫室氣體甲烷(CH4)排放量大和氮素去除率低的問(wèn)題。目前有關(guān)氧化塘產(chǎn)甲烷和脫氮過(guò)程的研究較少,主要集中在CH4排放通量和氮素去除率方面,有關(guān)微生物機(jī)制機(jī)理及其影響因素的研究尚未見(jiàn)報(bào)道。因此,從明確生態(tài)影響和滿足環(huán)保需求的層面,急需開(kāi)展氧化塘生境中產(chǎn)甲烷和脫氮過(guò)程相關(guān)微生物學(xué)研究,并闡明影響機(jī)理,以期為預(yù)測(cè)控制氧化塘溫室氣體CH4排放和優(yōu)化氧化塘廢水脫氮處理效能提供理論依據(jù)。本研究采集位于我國(guó)不同緯度地區(qū)的7個(gè)規(guī)�；i場(chǎng)廢水處理系統(tǒng)中氧化塘的水樣及底泥樣品,通過(guò)樣品的理化指標(biāo)分析,結(jié)合熒光定量PCR (qPCR)和Miseq高通量測(cè)序等分子生物學(xué)檢測(cè)技術(shù),研究了不同緯度地區(qū)規(guī)�；i場(chǎng)廢水處理系統(tǒng)中一級(jí)氧化塘和浙江省某一規(guī)�；i場(chǎng)廢水處理系統(tǒng)中多級(jí)氧化塘的產(chǎn)甲烷與脫氮過(guò)程相關(guān)功能基因豐度和微生物群落多樣性變化規(guī)律,揭示了影響氧化塘產(chǎn)甲烷過(guò)程的關(guān)鍵因素,提出了硫酸鹽還原過(guò)程對(duì)氧化塘氮素去除過(guò)程的影響機(jī)制,為氧化塘溫室氣體排放控制和氧化塘工藝脫氮效能的提升提供了理論依據(jù)。主要研究結(jié)論如下：(1)我國(guó)不同緯度地區(qū)規(guī)�；i場(chǎng)廢水處理系統(tǒng)中一級(jí)氧化塘底泥中產(chǎn)甲烷微生物活性和豐度均非常高,表明氧化塘是一個(gè)巨大的潛在溫室氣體CH4排放源。根據(jù)測(cè)得的一級(jí)氧化塘底泥產(chǎn)甲烷和甲烷氧化活性以及我國(guó)氧化塘的數(shù)量與分布情況估算,我國(guó)畜禽養(yǎng)殖業(yè)廢水處理系統(tǒng)中氧化塘底泥每年排放的CH4量為1.78-2.68 Tg,約占到全球人為CH4排放量的0.56-0.84%。此外,通過(guò)對(duì)浙江省杭州市某規(guī)�；i場(chǎng)廢水處理系統(tǒng)中連續(xù)四級(jí)氧化塘的水樣和底泥理化指標(biāo)、產(chǎn)甲烷微生物活性及其豐度的分析可以發(fā)現(xiàn),氧化塘進(jìn)水COD負(fù)荷對(duì)同一地點(diǎn)多級(jí)氧化塘產(chǎn)甲烷過(guò)程的影響最為顯著。因此,從控制溫室氣體CH4排放,應(yīng)對(duì)氣候變化的角度出發(fā),氧化塘不適合直接應(yīng)用于養(yǎng)殖廢水厭氧發(fā)酵液的處理,應(yīng)通過(guò)優(yōu)化氧化塘前期設(shè)計(jì)、強(qiáng)化進(jìn)水固液分離效果和設(shè)置相應(yīng)的生化處理單元來(lái)降低氧化塘進(jìn)水有機(jī)質(zhì)負(fù)荷,以減少氧化塘溫室氣體CH4排放量。(2)運(yùn)用分子生物學(xué)檢測(cè)技術(shù),對(duì)比分析了不同緯度地區(qū)一級(jí)氧化塘底泥中產(chǎn)甲烷微生物活性、豐度和群落結(jié)構(gòu)與功能的變化規(guī)律,發(fā)現(xiàn)年平均溫度(MAT, mean annual temperature)是影響不同緯度地區(qū)一級(jí)氧化塘底泥產(chǎn)甲烷過(guò)程的關(guān)鍵因素。隨著氧化塘所在區(qū)域MAT的升高,氧化塘底泥中產(chǎn)甲烷微生物活性和豐度均呈現(xiàn)極顯著的上升趨勢(shì)。高溫區(qū)氧化塘底泥以WCHD3-30主導(dǎo)的氫營(yíng)養(yǎng)型產(chǎn)甲烷古菌為主,而低溫區(qū)氧化塘底泥則以甲烷鬃菌科(Methanosaetaceae)主導(dǎo)的乙酸營(yíng)養(yǎng)型產(chǎn)甲烷古菌為主。隨著氧化塘所在區(qū)域MAT的變化,底泥細(xì)菌群落結(jié)構(gòu)組成也存在一定的變化規(guī)律,并與主導(dǎo)產(chǎn)甲烷古菌營(yíng)養(yǎng)型的變化規(guī)律相吻合。高溫區(qū)底泥細(xì)菌以具有產(chǎn)氫功能的乙酸氧化菌為主；低溫區(qū)底泥細(xì)菌種群大多與大分子有機(jī)質(zhì)降解和產(chǎn)乙酸過(guò)程相關(guān)。另外,冗余分析(RDA, redundancy analysis)的結(jié)果表明,MAT對(duì)一級(jí)氧化塘底泥中產(chǎn)甲烷古菌群落結(jié)構(gòu)組成的影響最為顯著。研究揭示了MAT影響氧化塘產(chǎn)甲烷過(guò)程的微生物學(xué)機(jī)理,并為未來(lái)全球氣候變暖的趨勢(shì)下,氧化塘CH4排放量呈現(xiàn)潛在性升高趨勢(shì)推斷提供了理論依據(jù)。(3)通過(guò)對(duì)不同緯度地區(qū)的一級(jí)氧化塘進(jìn)出水氮素的測(cè)定和比較發(fā)現(xiàn),一級(jí)氧化塘NH4+-N去除率均較低,最高去除率不足20%。采用定量PCR研究了氧化塘中氮循環(huán)相關(guān)功能基因(nifH, AOA amoA, AOB amoA, nirS和nirK)豐度的變化情況。結(jié)果表明,一級(jí)氧化塘水體和底泥中固氮功能基因(nifH)豐度普遍較高,而氨氧化功能基因(AOA amoA和AOB amoA)豐度極低。Pearson相關(guān)性分析的結(jié)果表明,一級(jí)氧化塘中nifH豐度與NH4+-N濃度呈現(xiàn)顯著的正相關(guān)關(guān)系,氨氧化功能基因豐度與NH4+-N濃度沒(méi)有表現(xiàn)出任何的顯著相關(guān)性。一級(jí)氧化塘中有可能發(fā)生固氮過(guò)程并由此促進(jìn)NH4+-N濃度的升高,而氨氧化過(guò)程并沒(méi)有導(dǎo)致NH4+-N濃度的下降。值得注意的是,一級(jí)氧化塘中SO42-濃度與nifH豐度存在顯著的正相關(guān)關(guān)系,且與AOB amoA豐度存在極顯著的負(fù)相關(guān)關(guān)系。因此,一級(jí)氧化塘中硫循環(huán)相關(guān)過(guò)程可能會(huì)強(qiáng)化氧化塘中NH4+-N的生成過(guò)程,同時(shí)削弱氨氧化過(guò)程,最終導(dǎo)致一級(jí)氧化塘極低的NH4+-N去除現(xiàn)象。(4)通過(guò)對(duì)浙江省某一規(guī)�；i場(chǎng)廢水處理系統(tǒng)中連續(xù)四級(jí)氧化塘底泥和水樣的理化指標(biāo)分析、氮循環(huán)相關(guān)功能基因(nifH, AOA amoA, AOB amoA, nirS和nirK)豐度、硫循環(huán)相關(guān)功能基因(dsrB和soxB)豐度的測(cè)定以及硫酸鹽還原過(guò)程抑制劑的添加實(shí)驗(yàn),證實(shí)了硫酸鹽還原過(guò)程是導(dǎo)致一級(jí)氧化塘脫氮性能低的主要原因。隨著氧化塘級(jí)數(shù)的增加,底泥和水樣SO42-濃度、硫酸鹽還原功能基因(dsrB)豐度和水體硫化物濃度逐漸下降,硫酸鹽還原過(guò)程減弱,NH4+-N去除率呈升高趨勢(shì)。RDA和Pearson相關(guān)性分析的結(jié)果表明,硫酸鹽還原過(guò)程生成的硫化物是影響氮循環(huán)和硫循環(huán)相關(guān)功能基因豐度整體變化的最主要因子,并且與氧化塘主要脫氮過(guò)程的功能基因(水體中AOB amoA和nirS)豐度均呈現(xiàn)顯著的負(fù)相關(guān)關(guān)系,表明硫化物顯著抑制氧化塘脫氮過(guò)程。另一方面,nifH和dsrB豐度呈現(xiàn)極顯著的正相關(guān)關(guān)系,硫酸鹽還原過(guò)程的存在可能會(huì)顯著提高nifH豐度,由此促進(jìn)固氮過(guò)程的發(fā)生,從而提高水體和底泥的NH4+-N濃度。抑制劑添加實(shí)驗(yàn)的結(jié)果表明,一級(jí)氧化塘(ZJ1)中的硫酸鹽還原過(guò)程被抑制后,NH4+-N的去除率提高了5.1-9.5%,ZJ1中硫酸鹽還原過(guò)程的存在抑制了20.9-32.8%的NH4-N去除。鑒于硫酸鹽還原過(guò)程對(duì)氧化塘脫氮過(guò)程的抑制作用,從提高氧化塘脫氮性能的角度出發(fā),氧化塘不適合直接應(yīng)用于硫化物濃度較高的厭氧發(fā)酵出水和SO42-濃度較高的養(yǎng)殖廢水、食品廠廢水和制藥業(yè)廢水等的處理。
[Abstract]:Oxygen pond is widely used in the treatment of anaerobic fermentation wastewater from large-scale pig farms as a wastewater treatment process with low capital investment, simple operation and management, and low energy consumption. However, with the high concentration of COD and NH4 + - N in the influent, the greenhouse gas methane (CH4) emissions and nitrogen removal from the pond are high. At present, there are few studies on methane production and nitrogen removal process in oxidation ponds, mainly focusing on CH4 emission flux and nitrogen removal rate, but there is no report on the mechanism of microbial mechanism and its influencing factors. Microbiological studies on methane and denitrification processes were carried out, and the influencing mechanism was clarified in order to provide theoretical basis for predicting and controlling greenhouse gas CH4 emission from oxidation ponds and optimizing denitrification efficiency of oxidation pond wastewater. The phase of methane production and denitrification in the primary oxidation pond and the multistage oxidation pond of a large-scale pig farm wastewater treatment system in Zhejiang Province were studied by analyzing the physical and chemical indexes of the samples and combining with fluorescence quantitative PCR (qPCR) and Mosq high-throughput sequencing techniques. The changes of functional gene abundance and microbial community diversity reveal the key factors affecting methane production in oxidation ponds. The mechanism of sulfate reduction affecting nitrogen removal in oxidation ponds is proposed, which provides a theoretical basis for controlling greenhouse gas emissions and improving nitrogen removal efficiency of oxidation ponds. The conclusions are as follows: (1) The methanogenic microbial activities and abundance in the sediments of the primary oxidation ponds in large-scale pig farm wastewater treatment systems in different latitudes of China are very high, indicating that the oxidation ponds are a huge potential source of greenhouse gas CH4 emission. The quantity and distribution of the ponds are estimated to be 1.78-2.68 Tg of CH4 discharged annually from the sediments of the oxidation ponds in the livestock and poultry wastewater treatment systems in China, accounting for about 0.56-0.84% of the global anthropogenic CH4 discharged. Therefore, from the point of view of controlling greenhouse gas CH4 emission and coping with climate change, oxidation pond is not suitable for the treatment of anaerobic fermentation broth of aquaculture wastewater. By optimizing the pre-design of oxidation pond, enhancing the effect of solid-liquid separation and setting up the corresponding biochemical treatment unit, the organic load in the inlet of oxidation pond can be reduced to reduce the greenhouse gas CH4 emissions. (2) The methanogenic microbial activities in the sediments of oxidation ponds in different latitudes were compared and analyzed by using molecular biological detection technology. It was found that the annual mean temperature (MAT) was the key factor affecting the methane production in the sediments of oxidation ponds in different latitudes. With the increase of MAT in the area where the oxidation ponds were located, the methane-producing microbial activities and abundance in the sediments of oxidation ponds increased significantly. WCHD3-30 dominated methanogenic archaea were dominant in the sediments of oxidation ponds at high temperatures, while methanosaetaceae dominated methanogenic archaea in the sediments of oxidation ponds at low temperatures. In addition, the results of redundancy analysis (RDA) showed that MAT had a significant effect on the degradation of macromolecular organic matter and the production of acetic acid. The study reveals the microbiological mechanism of MAT affecting methane production in oxidation ponds, and provides a theoretical basis for predicting the potential increase of CH4 emissions from oxidation ponds under the trend of global warming in the future. (3) Through the first-order oxidation ponds in different latitudes. The results showed that the removal rate of NH4 + - N in the primary oxidation pond was lower than 20%, and the highest removal rate was less than 20%. The abundance of nitrogen cycling related functional genes (nifH, AOA amoA, AOB amoA, nirS and nirK) in the primary oxidation pond was studied by quantitative PCR. Pearson correlation analysis showed that there was a significant positive correlation between the abundance of nifH and the concentration of NH4 + - N in primary oxidation ponds, and there was no significant correlation between the abundance of NH4 + - N and the abundance of NH4 + - N in primary oxidation ponds. It is noteworthy that there is a significant positive correlation between SO42-concentration and nifH abundance in primary oxidation ponds, and a very significant negative correlation between SO42-concentration and AOB amoA abundance. Cheng may intensify the formation of NH4 + - N in the oxidation pond and weaken the ammonia oxidation process, resulting in very low NH4 + - N removal in the primary oxidation pond. The abundances of AOB amoA, nirS and nirK, the abundances of sulfur cycling related functional genes (dsrB and soxB) and the addition of sulfate reduction process inhibitors confirmed that the sulfate reduction process was the main reason for the low denitrification performance of the primary oxidation pond. The results of RDA and Pearson correlation analysis showed that sulfides formed during sulfate reduction were the most important factors affecting the overall changes of functional gene abundance related to nitrogen cycle and sulfur cycle, and were related to oxygen. The abundances of functional genes (AOB amoA and nirS) in the main denitrification processes in the ponds were negatively correlated, suggesting that sulfides significantly inhibited the denitrification process in the ponds. The experimental results showed that the removal rate of NH4 + - N increased by 5.1-9.5% and the removal rate of NH4 - N by 20.9-32.8% in the first-order oxidation pond (ZJ1) when the sulfate reduction process was inhibited. From the point of view of improving the denitrification performance of oxidation pond, oxidation pond is not suitable for the treatment of anaerobic fermentation effluent with high sulfide concentration, aquaculture wastewater with high SO42-concentration, food factory wastewater and pharmaceutical wastewater.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：X713
[Abstract]:Oxygen pond is widely used in the treatment of anaerobic fermentation wastewater from large-scale pig farms as a wastewater treatment process with low capital investment, simple operation and management, and low energy consumption. However, with the high concentration of COD and NH4 + - N in the influent, the greenhouse gas methane (CH4) emissions and nitrogen removal from the pond are high. At present, there are few studies on methane production and nitrogen removal process in oxidation ponds, mainly focusing on CH4 emission flux and nitrogen removal rate, but there is no report on the mechanism of microbial mechanism and its influencing factors. Microbiological studies on methane and denitrification processes were carried out, and the influencing mechanism was clarified in order to provide theoretical basis for predicting and controlling greenhouse gas CH4 emission from oxidation ponds and optimizing denitrification efficiency of oxidation pond wastewater. The phase of methane production and denitrification in the primary oxidation pond and the multistage oxidation pond of a large-scale pig farm wastewater treatment system in Zhejiang Province were studied by analyzing the physical and chemical indexes of the samples and combining with fluorescence quantitative PCR (qPCR) and Mosq high-throughput sequencing techniques. The changes of functional gene abundance and microbial community diversity reveal the key factors affecting methane production in oxidation ponds. The mechanism of sulfate reduction affecting nitrogen removal in oxidation ponds is proposed, which provides a theoretical basis for controlling greenhouse gas emissions and improving nitrogen removal efficiency of oxidation ponds. The conclusions are as follows: (1) The methanogenic microbial activities and abundance in the sediments of the primary oxidation ponds in large-scale pig farm wastewater treatment systems in different latitudes of China are very high, indicating that the oxidation ponds are a huge potential source of greenhouse gas CH4 emission. The quantity and distribution of the ponds are estimated to be 1.78-2.68 Tg of CH4 discharged annually from the sediments of the oxidation ponds in the livestock and poultry wastewater treatment systems in China, accounting for about 0.56-0.84% of the global anthropogenic CH4 discharged. Therefore, from the point of view of controlling greenhouse gas CH4 emission and coping with climate change, oxidation pond is not suitable for the treatment of anaerobic fermentation broth of aquaculture wastewater. By optimizing the pre-design of oxidation pond, enhancing the effect of solid-liquid separation and setting up the corresponding biochemical treatment unit, the organic load in the inlet of oxidation pond can be reduced to reduce the greenhouse gas CH4 emissions. (2) The methanogenic microbial activities in the sediments of oxidation ponds in different latitudes were compared and analyzed by using molecular biological detection technology. It was found that the annual mean temperature (MAT) was the key factor affecting the methane production in the sediments of oxidation ponds in different latitudes. With the increase of MAT in the area where the oxidation ponds were located, the methane-producing microbial activities and abundance in the sediments of oxidation ponds increased significantly. WCHD3-30 dominated methanogenic archaea were dominant in the sediments of oxidation ponds at high temperatures, while methanosaetaceae dominated methanogenic archaea in the sediments of oxidation ponds at low temperatures. In addition, the results of redundancy analysis (RDA) showed that MAT had a significant effect on the degradation of macromolecular organic matter and the production of acetic acid. The study reveals the microbiological mechanism of MAT affecting methane production in oxidation ponds, and provides a theoretical basis for predicting the potential increase of CH4 emissions from oxidation ponds under the trend of global warming in the future. (3) Through the first-order oxidation ponds in different latitudes. The results showed that the removal rate of NH4 + - N in the primary oxidation pond was lower than 20%, and the highest removal rate was less than 20%. The abundance of nitrogen cycling related functional genes (nifH, AOA amoA, AOB amoA, nirS and nirK) in the primary oxidation pond was studied by quantitative PCR. Pearson correlation analysis showed that there was a significant positive correlation between the abundance of nifH and the concentration of NH4 + - N in primary oxidation ponds, and there was no significant correlation between the abundance of NH4 + - N and the abundance of NH4 + - N in primary oxidation ponds. It is noteworthy that there is a significant positive correlation between SO42-concentration and nifH abundance in primary oxidation ponds, and a very significant negative correlation between SO42-concentration and AOB amoA abundance. Cheng may intensify the formation of NH4 + - N in the oxidation pond and weaken the ammonia oxidation process, resulting in very low NH4 + - N removal in the primary oxidation pond. The abundances of AOB amoA, nirS and nirK, the abundances of sulfur cycling related functional genes (dsrB and soxB) and the addition of sulfate reduction process inhibitors confirmed that the sulfate reduction process was the main reason for the low denitrification performance of the primary oxidation pond. The results of RDA and Pearson correlation analysis showed that sulfides formed during sulfate reduction were the most important factors affecting the overall changes of functional gene abundance related to nitrogen cycle and sulfur cycle, and were related to oxygen. The abundances of functional genes (AOB amoA and nirS) in the main denitrification processes in the ponds were negatively correlated, suggesting that sulfides significantly inhibited the denitrification process in the ponds. The experimental results showed that the removal rate of NH4 + - N increased by 5.1-9.5% and the removal rate of NH4 - N by 20.9-32.8% in the first-order oxidation pond (ZJ1) when the sulfate reduction process was inhibited. From the point of view of improving the denitrification performance of oxidation pond, oxidation pond is not suitable for the treatment of anaerobic fermentation effluent with high sulfide concentration, aquaculture wastewater with high SO42-concentration, food factory wastewater and pharmaceutical wastewater.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：X713
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 Chong Wang;Jiane Zuo;Xiaojie Chen;Wei Xing;Linan Xing;Peng Li;Xiangyang Lu;Chao Li;;Microbial community structures in an integrated two-phase anaerobic bioreactor fed by fruit vegetable wastes and wheat straw[J];Journal of Environmental Sciences;2014年12期
2 吳根義;廖新O，
本文編號(hào)：2209117
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