電解強化人工濕地脫氮除磷過程與機理研究
發(fā)布時間：2018-09-14 09:19
【摘要】：本文基于電化學(xué)反應(yīng)穩(wěn)定高效的特點,開展了電化學(xué)與人工濕地聯(lián)合脫氮除磷過程與機理研究。構(gòu)建電解-生物濾床\人工濕地室內(nèi)小試裝置,研究不同人工濕地基質(zhì)、電極布置方式、電解時間、電流密度、水力停留時間(Hydraulic retention time,HRT)等電解設(shè)備和工藝參數(shù)對硝態(tài)氮(NO_3~--N)和磷酸鹽-磷(PO_4~(3-)-P)去除效果的影響,并分析電解對濕地植物和基質(zhì)生物膜細(xì)菌群落結(jié)構(gòu)的影響。開發(fā)了一種新型的光伏電解人工濕地技術(shù),應(yīng)用于污水處理廠尾水的深度凈化處理。獲得的主要結(jié)論如下：電解-生物濾床(Electrolysis-integrated biofilter, E-BF)將電解引入生物濾床處理工藝中,E-BF以沸石作為基質(zhì),有利于模擬廢水中氨氮(NH_~(3-)-N)的去除；鐵電極作為電解反應(yīng)的陽極,電解后產(chǎn)生Fe~(2+), Fe~(2+)進(jìn)一步氧化成Fe~(3+), Fe~(3+)與水體中OH-生成Fe(OH)_3絮凝劑,鐵離子與磷酸鹽的化學(xué)反應(yīng)以及Fe(OH)_3的絮凝沉淀作用有利于PO_4~(3-)-P的去除�；|(zhì)吸附的氨氮在微生物作用下轉(zhuǎn)化為亞硝態(tài)氮(NO_2~--N)和NO_3~--N, E-BF中N02-N和NO_3~--N的積累較對照組(Biofilter, BF)少。在不同的電解條件和PO_4~(3-)-P的進(jìn)水濃度下,去除PO43--P的最低電耗為1.1kW·h/g。16S rDNA測序結(jié)果表明E-BF基質(zhì)中有一定含量的鐵硫細(xì)菌,在鐵的生物化學(xué)轉(zhuǎn)化過程中發(fā)生作用。電解-水平潛流人工濕地(Electrolysis-integrated horizontal subsurface-flow constructed wetland system, E-HFCWs)處理模擬廢水的研究結(jié)果表明電極的布置方式會影響氮磷去除效果,采用雙陰極的電極布置方式有利于NO_3~--N和PO43--P的去除；最適宜的電流密度、電解時間和HRT分別為0.07mA/cm2、8h和8h；同時電解會導(dǎo)致電極周圍的濕地床體形成一個相對堿性的、溫度略高和氧化還原電位(Oxidation-reduction potential, ORP)較低的微環(huán)境,有利于NH_3~--N和NO_3~--N的同步微生物轉(zhuǎn)化；對不同HRT條件下E-HFCWs對氮磷去除電耗結(jié)果分析表明：去除單位總氮最低電耗為0.026 kW·h/g (HRT=4h),去除單位PO_4~(3-)-P電耗最低為0.112kW·h/g(HRT=2h); 16S rDNA結(jié)果表明,E-HFCWs基質(zhì)表面生物膜的細(xì)菌主要屬于β-proteobacteria,與對照組(Horizontal subsurface-flow constructed wetland system, HFCWs)相比,電解導(dǎo)致其門和屬類數(shù)量相對減少,但是其中的Hydrogenophaga屬的細(xì)菌和Xanthomonadaceae科的細(xì)菌含量有所增加,它們分別是以氫和亞鐵離子作為電子供體的自養(yǎng)反硝化微生物,在電解-人工濕地脫氮過程中發(fā)揮作用。電解-生物質(zhì)炭水平潛流人工濕地(Electrolysis-integrated biochar horizontal subsurface-flow constructed wetland system, E-B-HFCWs)以生物質(zhì)炭作為濕地基質(zhì),同時添加鐵電極構(gòu)成電化學(xué)反應(yīng)體系,不僅在較低的電耗條件下具有較高的脫氮除磷效果,而且實現(xiàn)了生物質(zhì)炭的原位電化學(xué)改性,提高了生物質(zhì)炭對NO_3~--N的吸附能力,而且出水中鐵離子含量較低,出水色度大大降低。E-B-HFCWs對COD也具有一定的去除效果。對濕地植物生長和生理生化指標(biāo)的結(jié)果分析表明電解對濕地植物生長影響較小。B-HFCWs基質(zhì)生物膜主要以Proteobacteria、Actinobacteria、Acidobacteria門細(xì)菌為主。光伏電解人工濕地將電解引入人工濕地處理過程中,同時以光伏太陽能作為電解反應(yīng)的能源,該濕地處理污水處理廠尾水的年運行結(jié)果表明,光伏電解人工濕地有利于降低電解反應(yīng)所需電耗；以吸附材料生物質(zhì)炭作為濕地基質(zhì)有利于污染物的原位濃縮；濕地植物的根區(qū)微環(huán)境有利于犧牲陽極法對PO_4~(3-)-P的絮凝沉淀作用和濕地基質(zhì)表面微生物的生長；光伏電解人工濕地較傳統(tǒng)人工濕地強化了高濃度NO_3~--N和低濃度PO_4~(3-)-P的同步去除,有利于污水處理廠尾水的深度凈化,具有良好的應(yīng)用前景。
[Abstract]:Based on the characteristics of stable and efficient electrochemical reaction, the process and mechanism of combined electrochemical and constructed wetland nitrogen and phosphorus removal were studied in this paper. The effects of electrolysis equipment and process parameters such as RT on the removal efficiency of nitrate nitrogen (NO_3-N) and phosphate phosphorus (PO_4-3-P) were studied. The effects of electrolysis on the bacterial community structure of wetland plants and matrix biofilm were analyzed. A new photovoltaic electrolysis constructed wetland technology was developed and applied to the advanced purification of wastewater treatment plant tail water. The main conclusions are as follows: Electrolysis-integrated biofilter (E-BF) introduces electrolysis into the biofilter process, E-BF uses zeolite as the substrate, which is conducive to the removal of NH_ (3-) -N in simulated wastewater; iron electrode as the anode of electrolysis reaction, produces Fe ~ (2+), and Fe ~ (2+) is further oxidized to Fe ~ (3+). Fe~ (3+) and OH-formed Fe (OH) _3 flocculant in water, chemical reaction of Fe~ (3+) with phosphate and flocculation and precipitation of Fe (OH) _3 are beneficial to the removal of PO_4~ (3-) -P. The accumulation of N02-N and NO_3-N in matrix adsorbed ammonia nitrogen is less than that in control group (Biofilter, BF). Under different electrolysis conditions and influent concentration of PO_4~ (3-) -P, the lowest power consumption of removing PO_43-P was 1.1kW H / g.16S rDNA sequencing. The results showed that there was a certain amount of iron-sulfur bacteria in E-BF matrix, which played an important role in the biochemical transformation of iron. The results of simulation wastewater treatment by onstructed wetland system (E-HFCWs) show that the electrode arrangement will affect the removal efficiency of nitrogen and phosphorus, and the electrode arrangement with double cathodes is beneficial to the removal of NO_3-N and PO43-P; the most suitable current density, electrolysis time and HRT are 0.07 mA/cm2, 8 h and 8 h, respectively; and electrolysis will lead to the electrode removal. A relatively alkaline microenvironment with slightly higher temperature and lower oxidation-reduction potential (ORP) was formed around the wetland bed, which facilitated the simultaneous microbial transformation of NH_3-N and NO_3-N. The lowest power consumption per PO_4~ (3-) - P removal unit was 0.112 kW h/g (HRT = 2h) at 6 kW h/g (HRT = 4h), and 16S rDNA analysis showed that the bacteria on the surface of E-HFCWs substrate mainly belonged to beta-proteobacteria. Compared with the control group (Horizontal subsurface-flow constructed wetland system, HFCWs), electrolysis resulted in a relative decrease in the number of phyla and genera, but the number of bacteria on the surface of E-HFCWs decreased. Hydrogenophaga and Xanthomonadaceae, which are autotrophic denitrifying microorganisms with hydrogen and ferrous ions as electron donors, play an important role in the process of electrolytic-constructed wetland denitrification. The E-B-HFCWs (izontal subsurface-flow constructed wetland system) uses biomass charcoal as wetland substrate and adds iron electrode to form an electrochemical reaction system. It not only has a high effect of nitrogen and phosphorus removal under low power consumption, but also realizes in-situ electrochemical modification of biomass char and improves the NO_3~--N activity of biomass char. E-B-HFCWs also had a certain removal effect on COD. The results showed that electrolysis had little effect on wetland plant growth and physiological and biochemical indicators. B-HFCWs substrate biofilms were mainly composed of Proteobacteria, Actinobacteria and Acidobacteria. Photovoltaic electrolysis constructed wetland introduces electrolysis into the process of constructed wetland treatment, and uses photovoltaic solar energy as the energy source of electrolysis reaction. The annual operation results of the wetland treatment of wastewater treatment plant tail water show that photovoltaic electrolysis constructed wetland is conducive to reducing the electricity consumption needed for electrolysis reaction; biomass carbon as adsorbent material is used as wet. In situ concentration of pollutants was favored by the ground material; flocculation and sedimentation of PO_4~ (3-) - P by sacrificial anode method and growth of microorganisms on the surface of wetland substrate were favored by the root zone microenvironment of wetland plants; simultaneous removal of high concentration of NO_3~ - N and low concentration of PO_4~ (3-) - P was enhanced by the photovoltaic electrolysis constructed wetland compared with the traditional constructed wetland. The deep purification of tail water in water treatment plant has a good application prospect.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：X703
本文編號：2242280
[Abstract]:Based on the characteristics of stable and efficient electrochemical reaction, the process and mechanism of combined electrochemical and constructed wetland nitrogen and phosphorus removal were studied in this paper. The effects of electrolysis equipment and process parameters such as RT on the removal efficiency of nitrate nitrogen (NO_3-N) and phosphate phosphorus (PO_4-3-P) were studied. The effects of electrolysis on the bacterial community structure of wetland plants and matrix biofilm were analyzed. A new photovoltaic electrolysis constructed wetland technology was developed and applied to the advanced purification of wastewater treatment plant tail water. The main conclusions are as follows: Electrolysis-integrated biofilter (E-BF) introduces electrolysis into the biofilter process, E-BF uses zeolite as the substrate, which is conducive to the removal of NH_ (3-) -N in simulated wastewater; iron electrode as the anode of electrolysis reaction, produces Fe ~ (2+), and Fe ~ (2+) is further oxidized to Fe ~ (3+). Fe~ (3+) and OH-formed Fe (OH) _3 flocculant in water, chemical reaction of Fe~ (3+) with phosphate and flocculation and precipitation of Fe (OH) _3 are beneficial to the removal of PO_4~ (3-) -P. The accumulation of N02-N and NO_3-N in matrix adsorbed ammonia nitrogen is less than that in control group (Biofilter, BF). Under different electrolysis conditions and influent concentration of PO_4~ (3-) -P, the lowest power consumption of removing PO_43-P was 1.1kW H / g.16S rDNA sequencing. The results showed that there was a certain amount of iron-sulfur bacteria in E-BF matrix, which played an important role in the biochemical transformation of iron. The results of simulation wastewater treatment by onstructed wetland system (E-HFCWs) show that the electrode arrangement will affect the removal efficiency of nitrogen and phosphorus, and the electrode arrangement with double cathodes is beneficial to the removal of NO_3-N and PO43-P; the most suitable current density, electrolysis time and HRT are 0.07 mA/cm2, 8 h and 8 h, respectively; and electrolysis will lead to the electrode removal. A relatively alkaline microenvironment with slightly higher temperature and lower oxidation-reduction potential (ORP) was formed around the wetland bed, which facilitated the simultaneous microbial transformation of NH_3-N and NO_3-N. The lowest power consumption per PO_4~ (3-) - P removal unit was 0.112 kW h/g (HRT = 2h) at 6 kW h/g (HRT = 4h), and 16S rDNA analysis showed that the bacteria on the surface of E-HFCWs substrate mainly belonged to beta-proteobacteria. Compared with the control group (Horizontal subsurface-flow constructed wetland system, HFCWs), electrolysis resulted in a relative decrease in the number of phyla and genera, but the number of bacteria on the surface of E-HFCWs decreased. Hydrogenophaga and Xanthomonadaceae, which are autotrophic denitrifying microorganisms with hydrogen and ferrous ions as electron donors, play an important role in the process of electrolytic-constructed wetland denitrification. The E-B-HFCWs (izontal subsurface-flow constructed wetland system) uses biomass charcoal as wetland substrate and adds iron electrode to form an electrochemical reaction system. It not only has a high effect of nitrogen and phosphorus removal under low power consumption, but also realizes in-situ electrochemical modification of biomass char and improves the NO_3~--N activity of biomass char. E-B-HFCWs also had a certain removal effect on COD. The results showed that electrolysis had little effect on wetland plant growth and physiological and biochemical indicators. B-HFCWs substrate biofilms were mainly composed of Proteobacteria, Actinobacteria and Acidobacteria. Photovoltaic electrolysis constructed wetland introduces electrolysis into the process of constructed wetland treatment, and uses photovoltaic solar energy as the energy source of electrolysis reaction. The annual operation results of the wetland treatment of wastewater treatment plant tail water show that photovoltaic electrolysis constructed wetland is conducive to reducing the electricity consumption needed for electrolysis reaction; biomass carbon as adsorbent material is used as wet. In situ concentration of pollutants was favored by the ground material; flocculation and sedimentation of PO_4~ (3-) - P by sacrificial anode method and growth of microorganisms on the surface of wetland substrate were favored by the root zone microenvironment of wetland plants; simultaneous removal of high concentration of NO_3~ - N and low concentration of PO_4~ (3-) - P was enhanced by the photovoltaic electrolysis constructed wetland compared with the traditional constructed wetland. The deep purification of tail water in water treatment plant has a good application prospect.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：X703
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 汪鋒;錢莊;張周;張雅晶;繆恒鋒;;污水處理廠尾水對排放河道水質(zhì)的影響[J];安徽農(nóng)業(yè)科學(xué);2016年14期
2 董穎博;林海;;Ammonia nitrogen removal from aqueous solution using zeolite modified by microwave-sodium acetate[J];Journal of Central South University;2016年06期
3 李崇梅;傅崇輝;;人口規(guī)模與廢污水排放量關(guān)系的動態(tài)穩(wěn)定性研究[J];資源科學(xué);2016年06期
4 張尊舉;張仁志;董亞榮;金泥沙;王曉娜;;污水處理廠尾水資源化利用[J];中國環(huán)境管理干部學(xué)院學(xué)報;2016年01期
5 李熔;宋長忠;趙旭;冒冉;;Pd/rGO/C電極催化還原硝酸鹽[J];環(huán)境工程學(xué)報;2016年02期
6 張千;范皓翔;張逸洲;徐鈺焱;吉芳英;;固體碳源生物膜反應(yīng)器的脫氮性能及機理研究[J];中國給水排水;2015年19期
7 舒柳;;不同類型人工濕地凈化水質(zhì)季節(jié)變化分析[J];江蘇農(nóng)業(yè)科學(xué);2015年09期
8 張華;孫盛;;我國表面流人工濕地系統(tǒng)對污染物去除效果研究現(xiàn)狀[J];廣東林業(yè)科技;2015年04期
9 左倬;陳煜權(quán);成必新;胡偉;朱雪誕;倉基俊;王鵬;;不同植物配置下人工濕地大型底棲動物群落特征及其與環(huán)境因子的關(guān)系[J];生態(tài)學(xué)報;2016年04期
10 王文林;韓睿明;王國祥;唐曉燕;梁斌;;濕地植物根系泌氧及其在自然基質(zhì)中的擴散效應(yīng)研究進(jìn)展[J];生態(tài)學(xué)報;2015年22期
，本文編號：2242280
本文鏈接：http://sikaile.net/shoufeilunwen/gckjbs/2242280.html
最近更新
教材專著
