-
餐饮行业的餐厨垃圾产量逐年递增[1-2]。据联合国粮食及农业组织(Food and Agriculture Organization of the United Nations,FAO)统计,目前全球每年产生的餐厨垃圾约16亿吨,预计到2025年,全球每年餐厨垃圾产量可能会高达25亿吨[3]。“预处理+厌氧消化”因其处理量大、占地面积小、臭味小、废物资源化等优点已成为餐厨垃圾处理的主流工艺[4-5]。但餐厨垃圾厌氧消化过程中会产生大量高COD、高NH4+-N、高SS、高油脂、高盐的餐厨垃圾厌氧沼液[6]。餐厨沼液的资源化、无害化处理成为亟待解决的市政、环境和公共卫生问题[7-9]。目前,餐厨沼液处理多采用“预处理+生化+深度处理”相结合的工艺。生化处理主要包括SBR工艺、A/O工艺、MBR工艺等,但大都具有碳源与碱度不足、脱氮能力有限、处理成本过高、运行维护难度高等问题[10],应探索更高效、节能的餐厨沼液处理工艺[11]。
厌氧氨氧化(anaerobic ammonium oxidation,anammox)因具有节省曝气能耗、无需外加碳源、污泥产量低、运行成本低等优势[12-13],自1995年被发现以来便成为污水处理领域的研究热点[14]。一段式短程硝化-厌氧氨氧化工艺(partial nitrification/anammox,PN/A)是先通过氨氧化细菌(aerobic ammonia-oxidizing bacteria,AOB)将污水中的部分NH4+-N好氧氧化为NO2−-N,再通过厌氧氨氧化菌(anaerobic ammonia oxidizing bacteria,AnAOB)的代谢作用,将剩余的NH4+-N与NO2−-N转化为NO3−-N和N2。该工艺主要应用于垃圾渗滤液[15]、化工废水[16]、养殖废水[17]等高氨氮废水的处理,在餐厨沼液处理方面却鲜有报道。
膜曝气生物膜反应器(membrane aerated biofilm reactor,MABR)是一项颇具节能潜力的技术,凭借其高效脱氮、占地面积小等优势,逐渐成为研究及应用的热点[18]。MABR具有无泡曝气[19]、异向传质[20]、生物膜分层结构[21]三大特点。将一段式PN/A工艺与MABR反应器耦合处理餐厨沼液,可最大限度地发挥厌氧氨氧化工艺与MABR反应器优势。将陶瓷膜作为预处理去除餐厨沼液中大量COD、SS,再通过微氧曝气工艺的精确供氧实现耗氧有机物的进一步脱除,并保留NH4+-N,最终在MABR中进行深度脱氮。
本研究采用“陶瓷膜-微氧曝气-MABR”组合工艺,在MABR单元中耦合一段式PN/A工艺,以餐厨垃圾厌氧沼液为处理对象,探究该组合工艺对餐厨沼液中主要污染物的去除效果,以期为餐厨垃圾厌氧沼液的处理及厌氧氨氧化的工程应用提供参考。
陶瓷膜微氧曝气MABR强化PN/anammox工艺处理餐厨沼液
Treatment of food waste digestate by ceramic membrane-micro oxygen aeration-MABR enhanced PN/anammox process
-
摘要: 针对餐厨沼液高COD、高氨氮的特点,采用“陶瓷膜-微氧曝气-MABR”组合工艺处理餐厨沼液。将陶瓷膜作为预处理单元对沼液中的TSS及部分耗氧有机物 (以COD计) 、NH4+-N进行去除,出水进入微氧曝气单元后,耗氧有机物被进一步去除,并维持NH4+-N处于较低的硝化率。当微氧曝气单元运行稳定后,在MABR单元中启动一段式短程硝化-厌氧氨氧化工艺,进行深度脱氮研究。结果表明:陶瓷膜对TSS去除率达98%,COD降低了73%,NH4+-N去除率为14%;经过50 d的驯化,在DO低于0.5 mg·L−1的条件下,微氧曝气单元COD降低了90%,平均NH4+-N损失率仅为12.7%;出水三维荧光光谱显示剩余耗氧有机物为类富里酸和类腐殖酸,难以进一步被生物降解;MABR单元经过148 d的驯化启动,成功实现一段式短程硝化-厌氧氨氧化工艺的稳定运行,尾气压力为0.025 MPa时处理效果最佳,NH4+-N去除率为68%,NRR为0.30 kg N·(m3·d)−1,△NO3−-N/△NH4+-N稳定在0.11左右,OTE最高可达39%。本研究可为餐厨沼液的处理及厌氧氨氧化的工程应用提供参考。Abstract: In view of the characteristics of high COD and NH4+-N of food waste digestate, the combined process of "ceramic membrane-micro oxygen aeration-MABR" was used to treat food waste digestate. The ceramic membrane was used as pretreatment unit to remove TSS and some oxygen-consuming organic matter(COD) and NH4+-N. COD in effluent was further removed in the micro oxygen aeration tank and NH4+-N was maintained at a low nitrification rate. When stable operation of the micro-oxygen aeration was reached, the one-stage partial nitrification-anammox process was started in MABR unit to carry out advanced nitrogen removal research. The results showed that the removal rate of TSS, COD and NH4+-N by ceramic membrane was 98%, 73% and 14% respectively. After 50 days of domestication, when DO was lower than 0.5 mg·L−1, the removal rate of COD in micro oxygen aeration unit was 90%, and the average removal rate of NH4+-N was only 12.7%. The three-dimensional fluorescence spectrum of the effluent showed that the remaining COD were fulvic acid and humic acid, which were difficult to be further biodegraded. After 148 days of domestication and start-up, MABR unit successfully realized the stable operation of one-stage partial nitrification-anammox process. The treatment effect was the best when the tail gas pressure was 0.025 MPa, the removal rate of NH4+-N was 68%, the NRR was 0.30 kg N·(m3·d)−1, △NO3−-N/△NH4+-N was stable at 0.11, and the highest OTE was 39%. This study can provide reference for the treatment of food waste digestate and the engineering application of anammox.
-
Key words:
- food waste digestate /
- micro oxygen aeration /
- partial nitrification /
- anammox /
- MABR
-
表 1 微氧曝气池运行参数
Table 1. Operating parameters of micro oxygen aeration tank
阶段 时间/d 进水COD/(mg·L−1) 进水NH4+-N/(mg·L−1) 进水TN/(mg·L−1) C/N 曝气量/(L·min−1) 污泥回流比 Ⅰ 1~16 300~350 137~211 160~246 1.42~2.18 0.3 160% Ⅱ 17~34 400~450 107~213 125~249 1.91~3.96 0.4 160% Ⅲ 35~50 500~550 136~154 159~180 3.42~3.90 0.5 180% 注:各阶段SRT均为4~5d,HRT均为10 h,pH均为7.1~7.5。 表 2 MABR运行参数
Table 2. Operating parameters of MABR
阶段 时间/d 进水NH4+-N/(mg·L−1) 进水COD/(mg·L−1) 进水TN/(mg·L−1) C/N 尾气压力/MPa 尾气流量/(L·min−1) Ⅰ 1~36 100 64 116 0.64 0.015 0.80 Ⅱ 37~58 100 61 116 0.61 0.018 0.55 Ⅲ 59~93 150 57 175 0.38 0.025 0.10 Ⅳ 94~122 200 83 232 0.42 0.025 0.10 Ⅴ 123~148 250 63 292 0.25 0.025 0.10 注:各阶段污泥回流比均为200%。 表 3 陶瓷膜对餐厨沼液的处理效果
Table 3. Performance of ceramic membrane on treatment of food waste digestate
水样 COD/(mg·L−1) NH4+-N/(mg·L−1) TN/(mg·L−1) TSS/(mg·L−1) 盐度/(g·L−1) pH 餐厨沼液原水 8 000~15 000 2 000~3 500 2 300~3 800 10 000~14 100 8~10 7.9~8.1 陶瓷膜出水 2 000~4 300 1 600~3 200 1 900~3 400 30~120 6~8 8.1~8.2 去除率/% 73 14 15 98 22 注:COD、NH4+-N、TN、TSS、盐度去除率分别为73%、14%、15%、98%、22%。 -
[1] 胡新军, 张敏, 余俊锋, 等. 中国餐厨垃圾处理的现状、问题和对策[J]. 生态学报, 2012, 32(14): 4575-4584. [2] 王丽华, 李宇宸, 韩聪. 城市餐厨垃圾处理技术分析及思路分析[J]. 中国资源综合利用, 2018, 36(12): 73-75. [3] CONNOR J O, HOANG S A, BRADNEY L, et al. A review on the valorisation of food waste as a nutrient source and soil amendment[J]. Environmental Pollution. 2021, 272: 115985. [4] 邴君妍, 罗恩华, 金宜英, 等. 我国餐厨废弃物厌氧消化技术的物质流分析[J]. 环境工程, 2018, 36(8): 130-133. [5] 庄渊. 高效预处理+厌氧消化工艺处理餐厨垃圾工程实例[J]. 中国资源综合利用, 2018, 36(11): 86-88. [6] 谢苏峰, 尹贞, 薛秋玉, 等. 浅谈餐厨沼液的处理技术[J]. 安徽化工, 2020,46(5):81-84. [7] 成娟. 生活污水稀释餐厨垃圾厌氧消化液培养微藻及氮磷去除的研究[D]. 济南: 山东大学, 2017. [8] 郑炜, 杨兴兴, 万梅, 等. MBR组合工艺处理餐厨垃圾发酵废液的运行特性[J]. 水处理技术, 2018, 44(3): 118-120. [9] 吴健, 赵明星, 阮文权. A/O-MBR处理高COD和高氨氮餐厨废水试验研究[J]. 工业水处理, 2014, 34(4): 66-69. [10] 张春, 郑利兵, 郁达伟, 等. 沼液处理与资源化利用现状与展望[J]. 中国沼气, 2018, 36(5): 36-46. [11] 刘文蓉, 董飞, 王玉军, 等. UASB-MBR-NF-RO处理垃圾渗滤液与餐厨垃圾厌氧消化液[J]. 水处理技术, 2021, 47(9): 77-80. [12] KARTAL B, KUENEN J G, VAN LOOSDRECHT M C M. Sewage treatment with anammox science[J]. Science, 2010, 328(5979): 702-703. doi: 10.1126/science.1185941 [13] YANG W, HE S, HAN M, et al. Nitrogen removal performance and microbial community structure in the start-up and substrate inhibition stages of an anammox reactor[J]. Journal of Bioscience and Bioengineering, 2018, 126(1): 88-95. doi: 10.1016/j.jbiosc.2018.02.004 [14] VAN DE GRAAF A A, MULDER A, DE BRUIJN P, et al. Anaerobic oxidation of ammonium is a biologically mediated process[J]. Applied and Environmental Microbiology, 1995, 61(4): 1246-1251. doi: 10.1128/aem.61.4.1246-1251.1995 [15] WANG G, XU X, ZHOU L, et al. A pilot-scale study on the start-up of partial nitrification-anammox process for anaerobic sludge digester liquor treatment[J]. Bioresource Technology, 2017, 241: 181-189. doi: 10.1016/j.biortech.2017.02.125 [16] KELUSKAR R, NERURKAR A, DESAI A. Development of a simultaneous partial nitrification, anaerobic ammonia oxidation and denitrification (SNAD) bench scale process for removal of ammonia from effluent of a fertilizer industry[J]. Bioresource Technology, 2013, 130: 390-397. doi: 10.1016/j.biortech.2012.12.066 [17] ARRIAGADA C, GUZMÁN-FIERRO V, GIUSTINIANOVICH E, et al. NOB suppression and adaptation strategies in the partial nitrification-Anammox process for a poultry manure anaerobic digester[J]. Process Biochemistry, 2017, 58: 258-265. doi: 10.1016/j.procbio.2017.03.028 [18] 康晓峰, 王黎声, 刘春, 等. 膜曝气生物膜反应器生物脱氮研究进展[J]. 环境工程, 2021, 39(07): 38-45. [19] COTE P, BERSILLON J L, HUYARD A. Bubble-free aeration using membranes-mass-transfer analysis[J]. Journal of Membrane Science, 1989, 47(1/2): 91-106. [20] SYRON E, CASEY E. Membrane-aerated biofilms for high rate biotreatment: performance appraisal, engineering principles, scale-up, and development requirements[J]. Environmental Science & Technology, 2008, 42(6): 1833-1844. [21] YAMAGIWA K, OHKAWA A, HIRASA O. Simultaneous organic-carbon removal and nitrification by biofilm formed on oxygen enrichment membrane[J]. Journal of Chemical Engineering of Japan, 1994, 27(5): 638-643. doi: 10.1252/jcej.27.638 [22] 国家环境保护总局. 水和废水监测分析方法[M]. 4版. 北京: 中国环境科学出版社, 2002. [23] 江兴. 膜曝气生物膜反应器处理低碳氮比市政污水的同步脱氮除碳研究[D]. 广州: 广州大学, 2022. [24] 夏一帆, 王冰洁, 涂凌波, 等. DMBR短程硝化反硝化处理餐厨垃圾厌氧沼液[J]. 中国给水排水, 2021, 37(7): 27-33. [25] YCHEN W, WESTERHOFF P, LEENHEER J A, et al. Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter[J]. Environmental Science & Technology, 2003, 37(24): 5701-5710. [26] STEDMON C A, MARKAGER S. Resolving the variability in dissolved organic matter fluorescence in a temperate estuary and its catchment using PARAFAC analysis[J]. Limnology and Oceanography, 2005, 50(2): 686-697. doi: 10.4319/lo.2005.50.2.0686 [27] BAGHOTH S A, SHARMA S K, AMY G L. Tracking natural organic matter (NOM) in a drinking water treatment plant using fluorescence excitation-emission matrices and PARAFAC[J]. Water Research, 2011, 45(2): 797-809. doi: 10.1016/j.watres.2010.09.005 [28] LYON B A, CORY R M, WEINBERG H S. Changes in dissolved organic matter fluorescence and disinfection byproduct formation from UV and subsequent chlorination /chloramination[J]. Journal of Hazardous Materials, 2014, 264: 411-419. doi: 10.1016/j.jhazmat.2013.10.065 [29] 侯飞飞. MABR去除高盐废水中COD和氨氮的基础研究[D]. 天津: 天津大学, 2013. [30] LI J, ZHANG Q, LI X, et al. Rapid start-up and stable maintenance of domestic wastewater nitritation through short-term hydroxylamine addition[J]. Bioresource Technology, 2019, 278: 468-472. doi: 10.1016/j.biortech.2019.01.056 [31] KINDAICHI T, OKABE S, SATOH H, et al. Effects of hydroxylamine on microbial community structure and function of autotrophic nitrifying biofilms determined by in situ hybridization and the use of microelectrodes[J]. Water Science Technology, 2004, 49(11/12): 61-68. [32] SOLIMAN M, ELDYASTI A. Development of partial nitrification as a first step of nitrite shunt process in a sequential batch reactor (SBR) using ammonium oxidizing bacteria (AOB) controlled by mixing regime[J]. Bioresource Technology, 2016, 221: 85-95. doi: 10.1016/j.biortech.2016.09.023 [33] KOUBA V, CATRYSSE M, STRYJOVA H, et al. The impact of influent total ammonium nitrogen concentration on nitrite-oxidizing bacteria inhibition in moving bed biofilm reactor[J]. Water Science and Technology, 2014, 69(6): 1227-1233. doi: 10.2166/wst.2013.757 [34] 王小龙. 基于颗粒污泥的单级自养脱氮系统构建及其脱氮效能研究[D]. 哈尔滨: 哈尔滨工业大学, 2018. [35] MAGRÍ A, VANOTTI M B, SZÖGI A A. Anammox sludge immobilized in polyvinyl alcohol (PVA) cryogel carriers[J]. Bioresource Technology, 2012, 114(1): 231-240.