摘要
硫自养反硝化(SAD)是一种绿色低碳的污水脱氮技术,具有成本低、污泥产量少、无须外加有机碳源等优点,已成为污水脱氮技术研究的热点之一。阐述SAD填料组成与复合硫源填料的合成方法,归纳SAD固定床反应器和流化床反应器的结构及其适用条件,回顾SAD与电化学、异养反硝化、厌氧氨氧化耦合工艺等方面的研究进展,并总结SAD耦合技术的优缺点以及耦合工艺的脱氮特征。微生物的代谢功能是实现高效SAD的关键因素,列举不同代谢特性的SAD功能微生物种类,阐述代表性微生物Thiobacillus和Sulfurimonas在SAD过程中的反硝化特性及其生长条件。目前,SAD技术在填料、反应器和耦合工艺等方面取得显著进步,但仍面临诸多挑战,在SAD技术温度适应性、高处理负荷反应器设计以及工艺流程优化等方面进一步创新。
中国市政生活污水处理碳源不足问题突出,控氮减碳特别是低C/N污水中硝酸盐的低碳处理已成为行业重大技术挑
硫自养反硝化(SAD)是通过活性污泥中的SAD菌,硫化物作为电子供体,NO
随着“双碳”目标深入推进,具有绿色低碳特征的SAD技术愈发受到科研领域的关注。近几年来,SAD技术在工艺和反硝化微生物作用机制方面取得了新的进展。笔者简述不同种类SAD填料的研究进展,从反应器构型和工艺耦合等角度对SAD及SAD水处理集成工艺技术的研究进行回顾和总结,并展望该技术未来发展方向。
电子供体是SAD技术中反应效果及效率的决定性因
单质硫填料价格低、毒性小、便于运输和操作,在SAD技术中被广泛使用。研究表明,单质硫填料粒径越小,比表面积就越大,给微生物提供的代谢结合位点越多,可以更好地提升反硝化效率。粒径0.8、3 mm的单质硫填料在经过培养后,当进水NO
但单质硫的低水溶性(5 μg/L 20 ℃)导致脱氮效率难以进一步提
SAD工艺中会消耗大量碱度,降低出水pH
不仅如此,最优的SAD辅助填料还应当能保障填料具有良好透气性和传质条件,并且能为微生物生长提供良好环境。因此,提高填料比表面积有利于增加SAD微生物的附着生长和提升反硝化速率,一些可强化反硝化效率的新型复合硫源填料应运而生。例如,采用包埋法制备的硫铁生物填料具有疏松多孔结构,有效提高了填料的比表面积,在进水硝酸盐浓度为30 mg/L、HRT为10 h时脱氮效率可以达到99.8
SAD填料的形式多种多样,常有不同类型的反应器与之匹配。基于填料在反应器中的状态分为填充床反应器和流化床反应器两大类。
SAD填充床反应器(如
SAD流化床反应器(如
综上,填料的内部结构和不同的电子供体对反应器的脱氮效果均有影响,此外,不同的进水污水种类、水力停留时间、反应器的传质性能、排气排泥的效率等诸多因素对脱氮的影响都值得探究。在研究中需将这些参数进行模拟和优化,以设计最佳反应器构建形式,使脱氮效率进一步提高。

(a) SAD填充床反应器

(b) SAD流化床反应器
图1 SAD反应器类型示意图
Fig. 1 Schematic diagram of SAD reactor type
SAD过程会消耗硫源与碱度,并产生SO
SAD耦合电化学工艺(如

(a) 硫自养-电化学耦合工艺机理示意

(b) 某种硫自养-电化学反硝化耦合装置示意

(c) 硫自养-电化学反硝化耦合装置中NO
图2 SAD-电化学耦合工艺示意图
Fig. 2 Schematic diagram of sulfur autotrophic-electrochemical coupling process
还原路径示意
SAD和HD耦合有以下优点:1)无须外加有机碳源,降低了运行成本;2)减少副产物SO

(a) 污水处理工艺后接SAD滤池示意

(b) 投加了硫基载体的
图3 SAD-异养反硝化耦合工艺示意图
Fig. 3 Schematic diagram of coupling process of sulfur autotrophic-heterotrophic denitrification
厌氧氨氧化(Anammox)的优势同SAD一样,即无须外加有机物、无须曝气,可以大大节约经济成本,但Anammox过程将水中污染物NO
将SAD耦合部分硝化-厌氧氨氧化(PNA)工艺有着同样的作用机制,与传统的PNA和SAD工艺相比,耦合工艺中SAD产生的NO
微生物的代谢功能是实现高效SAD的关键。SAD的功能微生物种类、生长条件及其生理特性见
菌属 | 微生物功能 | 微生物类型 | 适宜温度T/℃ | 生长pH值 | 电子供体 | 电子受体 | 参考文献 |
---|---|---|---|---|---|---|---|
Thiobacillus denitrificans | 氧化还原态硫化物或单质硫 | 专性无机化能自养型菌 | 28~30 | 6.5~7.0 |
H |
NO |
[ |
Thiobacillus thiophilus | 氧化硫代硫酸根 | 兼性厌氧革兰氏阴性菌 | -2~30 | 6.3~8.7 |
S2O |
NO |
[ |
Thialkalivibrio nitratireducens | 硝酸盐还原 | 硫酸盐弧菌 | 30 | 8~10.5 |
多硫化物、H |
NO |
[ |
Sulfurimonas | 硫氧化单胞菌 | 化能自养菌 | 15~35 | 6.5~8.5 |
|
NO |
[ |
Sulfurimonas denitrificans | 氧化硫化物 | 脱氮嗜硫单胞菌 | 22 | 7.0 |
H |
NO |
[ |
Sulfuricella denitrificans | 反硝化作用 | 硫氧化自养菌 | 22 | 7.5~8.0 |
|
NO |
[ |
Paracoccus | 还原硝酸盐和亚硝酸盐 | 脱氮副球菌 | 22±1 | 7.5±0.3 |
|
NO |
[ |
Thiomicrospira CVO | 氧化硫化物还原硝酸盐 | 化能自养菌 | 5~35 | 5.5~8.5 |
H |
NO |
[ |
Ferritrophicum | 2价铁氧化为3价铁 | 铁氧化细菌 | 6.4~19.2 | 7.4~8.1 |
F |
NO |
[ |
Thiobacillus和Sulfurimonas是已报道的最普遍的两种SAD细菌,在SAD过程中,它们易受到如电子受体不同、水中有机碳含量和电子供体浓度等环境因素影响,使其相对丰度发生变化。Chen
SAD技术在填料、反应器、耦合工艺等方面的研究取得了显著进步,成为污水绿色低碳脱氮的重要技术选择,且中国已在部分工程上得到了推广和应用。然而,SAD技术的工程化应用仍面临诸多限制:SAD工艺温度适应性需提高、反应器处理负荷亟待提升以及工程化工艺缺乏进一步创新等。以下几个方面未来可能成为SAD研究重点:
1)开发适应低温的SAD技术。研制抗低温SAD菌、设计适合低温运行的SAD工艺系统、开发耐低温的SAD填料载体,克服因低温导致SAD过程脱氮效率低的问题,提高SAD的温度适用范围。
2)提高硫自养反应器的处理负荷。加快传质,促进
3)SAD工艺的创新与应用。现有大多数研究采用SAD生物滤池的形式用于污水的深度脱氮,这增加了污水处理的流程且作用单一。未来研究应进一步缩短现有工艺,直接将SAD复合填料引入主流水处理工艺中,探究SAD和异养反硝化细菌的协同脱碳机制,并开展工程应用研究。
参考文献
WU Z, LIU Y, LIANG Z Y, et al. Internal cycling, not external loading, decides the nutrient limitation in eutrophic lake: A dynamic model with temporal Bayesian hierarchical inference [J]. Water Research, 2017, 116: 231-240. [百度学术]
LI Y Y, LIU L, WANG H J. Mixotrophic denitrification for enhancing nitrogen removal of municipal tailwater: Contribution of heterotrophic/sulfur autotrophic denitrification and bacterial community [J]. Science of the Total Environment, 2022, 814: 151940. [百度学术]
LI X, SHI M, ZHANG M, et al. Progresses and challenges in sulfur autotrophic denitrification-enhanced Anammox for low carbon and efficient nitrogen removal [J]. Critical Reviews in Environmental Science and Technology, 2022, 52(24): 4379-4394. [百度学术]
WANG H C, LIU Y, YANG Y M, et al. Element sulfur-based autotrophic denitrification constructed wetland as an efficient approach for nitrogen removal from low C/N wastewater [J]. Water Research, 2022, 226: 119258. [百度学术]
LI Y Y, LIU Y X, LUO J H, et al. Emerging onsite electron donors for advanced nitrogen removal from anammox effluent of leachate treatment: A review and future applications [J]. Bioresource Technology, 2021, 341: 125905. [百度学术]
马航, 朱强, 朱亮, 等. 单质硫颗粒尺寸及反应器类型对硫自养反硝化反应器启动的影响[J]. 环境科学, 2016, 37(6): 2235-2242. [百度学术]
MA H, ZHU Q, ZHU L, et al. Effect of element sulfur particle size and type of the reactor on start-up of sulfur-based autotrophic denitrification reactor [J]. Environmental Science, 2016, 37(6): 2235-2242. (in Chinese) [百度学术]
KONG Z, FENG C P, CHEN N, et al. A soil infiltration system incorporated with sulfur-utilizing autotrophic denitrification (SISSAD) for domestic wastewater treatment [J]. Bioresource Technology, 2014, 159: 272-279. [百度学术]
UCAR D, YILMAZ T, DI CAPUA F, et al. Comparison of biogenic and chemical sulfur as electron donors for autotrophic denitrification in sulfur-fed membrane bioreactor (SMBR) [J]. Bioresource Technology, 2020, 299: 122574. [百度学术]
LI R H, GUAN M S, WANG W. Simultaneous arsenite and nitrate removal from simulated groundwater based on pyrrhotite autotrophic denitrification [J]. Water Research, 2021, 189: 116662. [百度学术]
LIU Y J, CHEN N, TONG S, et al. Performance enhancement of H2S-based autotrophic denitrification with bio-gaseous CO2 as sole carbon source through new pH adjustment materials [J]. Journal of Environmental Management, 2020, 261: 110157. [百度学术]
TIAN T, YU H Q. Denitrification with non-organic electron donor for treating low C/N ratio wastewaters [J]. Bioresource Technology, 2020, 299: 122686. [百度学术]
李天昕, 邱诚翔, 徐昊, 等. 硫/石灰石自养反硝化处理低碳高氮城市污水的工艺[J]. 环境工程学报, 2014, 8(3): 1062-1066. [百度学术]
LI T X, QIU C X, XU H, et al. Low carbon and high nitrogen concentration municiple wastewater treatment with sulfur/limestone autotrophic denitrification technology [J]. Chinese Journal of Environmental Engineering, 2014, 8(3): 1062-1066. (in Chinese) [百度学术]
SAHINKAYA E, DURSUN N, KILIC A, et al. Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: Control of sulfate production [J]. Water Research, 2011, 45(20): 6661-6667. [百度学术]
QAMBRANI N A, OH S E. Effect of dissolved oxygen tension and agitation rates on sulfur-utilizing autotrophic denitrification: Batch tests [J]. Applied Biochemistry and Biotechnology, 2013, 169(1): 181-191. [百度学术]
史航, 隆添翼, 柳聪, 等. 基于异养-硫自养反硝化耦合技术的陶粒-硫磺混合生物填料对城市污水处理厂尾水的深度脱氮[J]. 环境工程学报, 2022, 16(4): 1363-1372. [百度学术]
SHI H, LONG T Y, LIU C, et al. Deep nitrogen removal from urban wastewater by ceramsite-sulfur mixed biological fillers based on heterotrophy-sulfur autotrophic denitrification coupling technology [J]. Chinese Journal of Environmental Engineering, 2022, 16(4): 1363-1372. (in Chinese) [百度学术]
阮赟杰, 罗国芝, 谭洪新, 等. 硫/珊瑚石填料床的自养反硝化反应器[J]. 福建农林大学学报(自然科学版), 2009, 38(2): 198-202. [百度学术]
RUAN Y J, LUO G Z, TAN H X, et al. A sulfur and corallite packed-bed reactor for autotrophic denitrification [J]. Journal of Fujian Agriculture and Forestry University (Natural Science Edition), 2009, 38(2): 198-202. (in Chinese) [百度学术]
刘艳芳, 刘晓帅, 尹思婕, 等. 包埋硫铁生物填料的制备及自养反硝化性能[J]. 中国环境科学, 2022, 42(11): 5136-5143. [百度学术]
LIU Y F, LIU X S, YIN S J, et al. Preparation and autotrophic denitrification properties of embedded sulfur/iron biological filler [J]. China Environmental Science, 2022, 42(11): 5136-5143. (in Chinese) [百度学术]
WOO Y C, LEE J J, JEONG A, et al. Removal of nitrogen by a sulfur-based carrier with powdered activated carbon (PAC) for denitrification in membrane bioreactor (MBR) [J]. Journal of Water Process Engineering, 2020, 34: 101149. [百度学术]
LIANG J, CHEN N, TONG S, et al. Sulfur autotrophic denitrification (SAD) driven by homogeneous composite particles containing CaCO3-type kitchen waste for groundwater remediation [J]. Chemosphere, 2018, 212: 954-963. [百度学术]
VO T K Q, JEONG A, SONG J, et al. Nitrogen removal by using sulfur-based carriers: A comparison of configurations for the denitrification process [J]. Desalination and Water Treatment, 2019, 167: 212-217. [百度学术]
VO T K Q, KANG S, AN S N, et al. Exploring critical factors influencing on autotrophic denitrification by elemental sulfur-based carriers in upflow packed-bed bioreactors [J]. Journal of Water Process Engineering, 2021, 40: 101866. [百度学术]
HAN G B, PARK J K. NO
MA W C, ZHOU D P, ZHONG D, et al. Study of nitrogen removal efficiency of the filled bed reactors using alkali-treated corncobs-sulfur (mixotrophic) for treating the effluent from simulated urban wastewater plants [J]. Bioresource Technology, 2022, 349: 126630. [百度学术]
QIU Y Y, GUO J H, ZHANG L, et al. A high-rate sulfidogenic process based on elemental sulfur reduction: Cost-effectiveness evaluation and microbial community analysis [J]. Biochemical Engineering Journal, 2017, 128: 26-32. [百度学术]
ZHANG L L, SONG Y D, ZUO Y, et al. Integrated sulfur- and iron-based autotrophic denitrification process and microbial profiling in an anoxic fluidized-bed membrane bioreactor [J]. Chemosphere, 2019, 221: 375-382. [百度学术]
CARBONI M F, MILLS S, ARRIAGA S, et al. Autotrophic denitrification of nitrate rich wastewater in fluidized bed reactors using pyrite and elemental sulfur as electron donors [J]. Environmental Technology & Innovation, 2022, 28: 102878. [百度学术]
GAO M C, WANG S, REN Y, et al. Simultaneous removal of perchlorate and nitrate in a combined reactor of sulfur autotrophy and electrochemical hydrogen autotrophy [J]. Chemical Engineering Journal, 2016, 284: 1008-1016. [百度学术]
LIU Y W, NGO H H, GUO W S, et al. Modeling electron competition among nitrogen oxides reduction and N2O accumulation in hydrogenotrophic denitrification [J]. Biotechnology and Bioengineering, 2018, 115(4): 978-988. [百度学术]
CHEN F, LI Z L, YE Y, et al. Coupled sulfur and electrode-driven autotrophic denitrification for significantly enhanced nitrate removal [J]. Water Research, 2022, 220: 118675. [百度学术]
WANG H Y, LYU W L, HU X L, et al. Effects of current intensities on the performances and microbial communities in a combined bio-electrochemical and sulfur autotrophic denitrification (CBSAD) system [J]. Science of the Total Environment, 2019, 694: 133775. [百度学术]
WAN D J, LIU H J, LIU R P, et al. Study of a combined sulfur autotrophic with proton-exchange membrane electrodialytic denitrification technology: Sulfate control and pH balance [J]. Bioresource Technology, 2011, 102(23): 10803-10809. [百度学术]
CHEN F, YE Y, FAN B L, et al. Simultaneous removal of tetrachloroethylene and nitrate with a novel sulfur-packed biocathode system: The synergy between bioelectrocatalytic dechlorination and sulfur autotrophic denitrification [J]. Chemical Engineering Journal, 2022, 439: 135793. [百度学术]
SAHINKAYA E, DURSUN N. Use of elemental sulfur and thiosulfate as electron sources for water denitrification [J]. Bioprocess and Biosystems Engineering, 2015, 38(3): 531-541. [百度学术]
李祥, 马航, 黄勇, 等. 异养与硫自养反硝化协同处理高硝氮废水特性研究[J]. 环境科学, 2016, 37(7): 2646-2651. [百度学术]
LI X, MA H, HUANG Y, et al. Characteristics of a combined heterotrophic and sulfur autotrophic denitrification technology for removal of high nitrate in water [J]. Environmental Science, 2016, 37(7): 2646-2651. (in Chinese) [百度学术]
WANG S S, CHENG H Y, ZHANG H, et al. Sulfur autotrophic denitrification filter and heterotrophic denitrification filter: Comparison on denitrification performance, hydrodynamic characteristics and operating cost [J]. Environmental Research, 2021, 197: 111029. [百度学术]
WOO Y C, LEE J J, KIM H S. Removal of nitrogen from municipal wastewater by denitrification using a sulfur-based carrier: A pilot-scale study [J]. Chemosphere, 2022, 296: 133969. [百度学术]
QIANG J X, ZHOU Z, WANG K C, et al. Coupling ammonia nitrogen adsorption and regeneration unit with a high-load anoxic/aerobic process to achieve rapid and efficient pollutants removal for wastewater treatment [J]. Water Research, 2020, 170: 115280. [百度学术]
DU R, PENG Y Z, JI J T, et al. Partial denitrification providing nitrite: Opportunities of extending application for anammox [J]. Environment International, 2019, 131: 105001. [百度学术]
LI X, YUAN Y, HUANG Y, et al. Simultaneous removal of ammonia and nitrate by coupled
CHEN F M, LI X, YUAN Y, et al. An efficient way to enhance the total nitrogen removal efficiency of the Anammox process by
王拓. 厌氧氨氧化与硫自养反硝化两段式耦合工艺运行机理研究 [D]. 天津:天津城建大学, 2020: 70. [百度学术]
WANG T. Study on the mechanism of two-stage coupled process of anammox and sulfur-based autotrophic denitrification [D]. Tianjin: Tianjin Chengjian University, 2020: 70. [百度学术]
DENG Y F, WU D, HUANG H, et al. Exploration and verification of the feasibility of sulfide-driven partial denitrification coupled with anammox for wastewater treatment [J]. Water Research, 2021, 193: 116905. [百度学术]
LOTTI T, KLEEREBEZEM R, LUBELLO C, et al. Physiological and kinetic characterization of a suspended cell anammox culture [J]. Water Research, 2014, 60: 1-14. [百度学术]
DENG Y F, ZAN F X, HUANG H, et al. Coupling sulfur-based denitrification with anammox for effective and stable nitrogen removal: A review [J]. Water Research, 2022, 224: 119051. [百度学术]
ZHANG K, KANG T L, YAO S, et al. A novel coupling process with partial nitritation-anammox and short-cut sulfur autotrophic denitrification in a single reactor for the treatment of high ammonium-containing wastewater [J]. Water Research, 2020, 180: 115813. [百度学术]
POKORNA D, ZABRANSKA J. Sulfur-oxidizing bacteria in environmental technology [J]. Biotechnology Advances, 2015, 33(6): 1246-1259. [百度学术]
HAN F, ZHANG M R, SHANG H G, et al. Microbial community succession, species interactions and metabolic pathways of sulfur-based autotrophic denitrification system in organic-limited nitrate wastewater [J]. Bioresource Technology, 2020, 315: 123826. [百度学术]
LIU C S, LI Y Z, GAI J N, et al. Cultivation of sulfide-driven partial denitrification granules for efficient nitrite generation from nitrate-sulfide-laden wastewater [J]. Science of the Total Environment, 2022, 804: 150143. [百度学术]
CHEN F M, LI X, GU C W, et al. Selectivity control of nitrite and nitrate with the reaction of
MOULANA A, ANDERSON R E, FORTUNATO C S, et al. Selection is a significant driver of gene gain and loss in the pangenome of the bacterial genus Sulfurovum in geographically distinct deep-sea hydrothermal vents [J]. mSystems, 2020, 5(2): e00673-e00719. [百度学术]
QIU Y Y, ZHANG L, MU X T, et al. Overlooked pathways of denitrification in a sulfur-based denitrification system with organic supplementation [J]. Water Research, 2020, 169: 115084. [百度学术]
ZHANG R C, XU X J, CHEN C, et al. Interactions of functional bacteria and their contributions to the performance in integrated autotrophic and heterotrophic denitrification [J]. Water Research, 2018, 143: 355-366. [百度学术]
LI Y Y, WANG Y L, WAN D J, et al. Pilot-scale application of sulfur-limestone autotrophic denitrification biofilter for municipal tailwater treatment: Performance and microbial community structure [J]. Bioresource Technology, 2020, 300: 122682. [百度学术]
YANG J F, QIN Y J, LIU X Y, et al. Effects of different electron donors on nitrogen removal performance and microbial community of denitrification system [J]. Journal of Environmental Chemical Engineering, 2022, 10(3): 107915. [百度学术]
ZHANG Y W, WEI D Y, MORRISON L, et al. Nutrient removal through pyrrhotite autotrophic denitrification: Implications for eutrophication control [J]. Science of the Total Environment, 2019, 662: 287-296. [百度学术]
WANG W, WEI D Y, LI F C, et al. Sulfur-siderite autotrophic denitrification system for simultaneous nitrate and phosphate removal: From feasibility to pilot experiments [J]. Water Research, 2019, 160: 52-59. [百度学术]
KELLERMANN C, GRIEBLER C. Thiobacillus thiophilus sp. nov., a chemolithoautotrophic, thiosulfate-oxidizing bacterium isolated from contaminated aquifer sediments [J]. International Journal of Systematic and Evolutionary Microbiology, 2009, 59(3): 583-588. [百度学术]
SOROKIN D Y, TOUROVA T P, SJOLLEMA K A, et al. Thialkalivibrio nitratireducens sp. nov., a nitrate-reducing member of an autotrophic denitrifying consortium from a soda lake [J]. International Journal of Systematic and Evolutionary Microbiology, 2003, 53(Pt 6): 1779-1783. [百度学术]
KEN T K, SUZUKI M, NAKAGAWA S, et al. Sulfurimonas paralvinellae sp. nov., a novel mesophilic, hydrogen- and sulfur-oxidizing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent polychaete nest, reclassification of Thiomicrospira denitrificans as Sulfurimonas denitrificans comb. nov. and emended description of the genus Sulfurimonas [J]. International Journal of Systematic and Evolutionary Microbiology, 2006, 56(8): 1725-1733. [百度学术]
KOJIMA H, FUKUI M. Sulfuricella denitrificans Gen. nov., sp. nov., a sulfur-oxidizing autotroph isolated from a freshwater lake [J]. International Journal of Systematic and Evolutionary Microbiology, 2010, 60(Pt 12): 2862-2866. [百度学术]
CUI Y X, BISWAL B K, VAN LOOSDRECHT M C M, et al. Long term performance and dynamics of microbial biofilm communities performing sulfur-oxidizing autotrophic denitrification in a moving-bed biofilm reactor [J]. Water Research, 2019, 166: 115038. [百度学术]
SUN S S, LIU J, ZHANG M P, et al. Thiosulfate-driven autotrophic and mixotrophic denitrification processes for secondary effluent treatment: Reducing sulfate production and nitrous oxide emission [J]. Bioresource Technology, 2020, 300: 122651. [百度学术]
GEVERTZ D, TELANG A J, VOORDOUW G, et al. Isolation and characterization of strains CVO and FWKO B, two novel nitrate-reducing, sulfide-oxidizing bacteria isolated from oil field brine [J]. Applied and Environmental Microbiology, 2000, 66(6): 2491-2501. [百度学术]
QIAN J, LU H, JIANG F, et al. Beneficial co-treatment of simple wet flue gas desulphurization wastes with freshwater sewage through development of mixed denitrification–SANI process [J]. Chemical Engineering Journal, 2015, 262: 109-118. [百度学术]