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活性污泥作为污水处理厂的主要副产物,其产量在2017年已达4.328×107 t (以含水率80%计)[1],且处理费用可占污水处理厂总运行费用的60%[2-3]。由于多环芳烃(polycyclic aromatic hydrocarbons,PAHs)具有较低的溶解性和较高的辛醇/脂水分配系数,因此,在污水处理过程中,PAHs容易吸附到活性污泥上[4]。虽然PAHs在污水处理过程中的去除率能达到90%,但由于自身的疏水特征会使得PAHs聚集在活性污泥中[5]。根据MENG等[6]对过去14年间我国污泥中有机污染物的统计,干污泥中16种PAHs(∑PAHs)含量为0.1×103~17×103 μg·kg−1,平均含量为159 μg·kg−1。因此,活性污泥中不仅含有大量的有机质[7],而且还含有大量污染物质[8-9]。本课题组前期研究结果表明,秸秆、纤维素与污泥在不同配比下进行联合厌氧消化均能促进污泥中∑PAHs降解,其降解速率可达到29.86%~51.33%和14.82%~20.75%[10-11]。可见,秸秆对PAHs的促进能力强于纤维素。而根据CHANDRA等[12]的统计,一些常见作物(小麦、玉米、水稻)的秸秆的纤维素、半纤维素及木质素含量分别为25%~44.3%、30%~50%和10%~21%。其中,纤维素和半纤维素在厌氧条件下容易水解形成葡萄糖,从而为微生物的生长提供碳源。因此,为了解秸秆和纤维素为共基质时污泥中PAHs的降解机制,可利用秸秆和纤维素的主要水解产物葡萄糖为共基质。
本研究以葡萄糖为共基质,研究污泥与葡萄糖在不同配比下联合厌氧消化对污泥中PAHs去除效能及细菌群落的影响,并优化最佳配比,为深入了解秸秆和纤维素与污泥进行联合厌氧消化过程中PAHs的降解机制提供参考和技术支撑。
污泥与葡萄糖不同配比联合厌氧消化对污泥中多环芳烃去除效能及细菌群落的影响
Effect of different ratio of sludge to glucose combined with anaerobic co-digestion on polycyclic aromatic hydrocarbons removal efficiency and bacterial community in sludge
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摘要: 为分析污泥与葡萄糖不同配比进行联合厌氧消化对污泥中多环芳烃(PAHs)去除效能及细菌群落的影响,在中温(35±1) ℃条件下,以未添加葡萄糖的污泥厌氧消化为对照(CK),研究了活性污泥与葡萄糖按不同有机质含量(挥发性固体(VS)质量比)分别为1∶0.1、1∶0.3和1∶0.5对PAHs去除效能及细菌群落的影响。结果表明,葡萄糖添加量的增加并未进一步提高PAHs的降解能力。P1实验组(VS污泥∶VS葡萄糖=1∶0.1)对消化污泥中∑PAHs的去除能力最强;降解速率可达到(60.56±8.10)%;且高分子质量PAHs(≥4环)的降解速率显著高于低分子质量PAHs(2~3环)(P<0.05)。苯并(a)蒽、䓛、苯并(b)荧蒽和苯并(k)荧蒽的平均降解速率均大于62%;而苯并(a)芘的降解速率达到(59.60±14.05)%。此外,使用16S rRNA技术,检测消化污泥中细菌群落发现,向污泥中添加葡萄糖,可能通过促进Actinobacteria、Bacteroidetes_vadin HA17、Spirochaetes、Planctomycetes和norank_f_Anaerolineaceae菌群的生长,从而提高污泥中PAHs的去除能力。Abstract: In order to analyze the effects of the different ratio of sludge to glucose combined with anaerobic co-digestion on the removal efficiency of polycyclic aromatic hydrocarbons (PAHs) and bacterial communities in sludge, at medium temperature (35±1) ℃, the effects of different organic matter contents (as volatile solids (VS) mass ratio) for sludge and glucose of 1∶0.1, 1∶0.3 and 1∶0.5 on the removal efficiency of PAHs and bacterial community were compared with anaerobic digestion of sludge without added glucose (CK). The results showed that the increase of glucose amount did not further improve the degradation ability of PAHs. Among them, P1 experimental group (VSsludge∶VSglucose=1∶0.1) had the strongest removal ability of ∑PAHs in digested sludge, and degrading rate could reach (60.56±8.10)%. And the removal efficiency of high molecular weight PAHs (≥4 ring) was significantly higher than that of the low molecular weight PAHs (2~3 rings) (P<0.05). All the average degradation rates of benzo(a)pyrene, anthracene, benzo(b)fluoranthene and benzo(k)fluoranthene were higher than 62%, while the degradation rate of benzo(a)pyrene reached (59.60±14.05)%. In addition, 16S rRNA technology was used to detect the bacterial community in the digested sludge. It was found that the addition of glucose to the sludge could enhance PAHs removal in the sludge by promoting the growth of Actinobacteria, Bacteroidetes_vadin HA17, Spirochaetes, Planctomycetes and norank_f_Anaerolineaceae.
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Key words:
- sludge /
- anaerobic co-digestion /
- different ratio /
- PAHs /
- bacterial community
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表 1 实验污泥中PAHs含量
Table 1. Concentration of PAHs in experimental sludge
化合物中文名称 英文简写 PAHs含量/(μg·kg−1) 萘 NaP 41.72±12.89 苊 Ace 5.72±0.14 苊烯 Acy 14.95±0.88 芴 Flu 114.14±9.46 菲 Phe 669.85±52.13 蒽 Ant 43.57±4.42 荧蒽 Fluo 447.67±77.75 芘 Pyr 89.70±2.40 苯并(a)蒽 BaA 85.21±35.81 䓛 Chry 345.26±27.93 苯并(b)荧蒽 BbF 299.71±49.09 苯并(k)荧蒽 BkF 582.88±337.19 苯并(a)芘 BaP 305.56±117.10 总PAHs ∑PAHs 3 116.06±454.23 表 2 各样本序列统计
Table 2. Sequence statistics of each sample
样品名称 序列数量/条 OTU/个 Shannon Simpson CK 35 232 1 301 5.28 0.017 P1 29 228 1 455 5.51 0.030 P2 29 114 1 408 5.49 0.023 P3 29 482 1 311 4.97 0.033 -
[1] 杭世珺, 傅涛, 戴晓虎, 等. 技术路线没有走通, 产业没有融通, 政策缺乏贯通 污泥出路困境如何破?[J]. 环境经济, 2019(2): 34-39. [2] ZHAO J, GUI L, WANG Q, et al. Aged refuse enhances anaerobic digestion of waste activated sludge[J]. Water Research, 2017, 123: 724-733. doi: 10.1016/j.watres.2017.07.026 [3] WANG Q, WEI W, GONG Y, et al. Technologies for reducing sludge production in wastewater treatment plants: State of the art[J]. Science of the Total Environment, 2017, 587-588: 510-521. doi: 10.1016/j.scitotenv.2017.02.203 [4] CLARKE B O, SMITH S R. Review of 'emerging' organic contaminants in biosolids and assessment of international research priorities for the agricultural use of biosolids[J]. Environment International, 2011, 37(1): 226-247. doi: 10.1016/j.envint.2010.06.004 [5] APARICIO I, SANTOS J L, ALONSO E. Limitation of the concentration of organic pollutants in sewage sludge for agricultural purposes: A case study in South Spain[J]. Waste Management, 2009, 29(5): 1747-1753. doi: 10.1016/j.wasman.2008.11.003 [6] MENG X Z, VENKATESAN A K, NI Y L, et al. Organic contaminants in Chinese sewage sludge: A meta-analysis of the literature of the past 30 years[J]. Environmental Science & Technology, 2016, 50(11): 5454-5466. [7] 李素慧, 许智华, 樊小军. 污水处理厂污泥处理处置现状分析及建议[J]. 能源研究与信息, 2011, 27(4): 187-192. doi: 10.3969/j.issn.1008-8857.2011.04.001 [8] LAVADO R S, RODRIGUEZ M B, TABOADA M A. Treatment with biosolids affects soil availability and plant uptake of potentially toxic elements[J]. Agriculture Ecosystems & Environment, 2005, 109(3/4): 360-364. [9] SHOBER A L, STEHOUWER R C, MACNEAL K E. Chemical fractionation of trace elements in biosolid-amended soils and correlation with trace elements in crop tissue[J]. Communications in Soil Science & Plant Analysis, 2007, 38(7): 1029-1046. [10] International Journal of Environmental Science and Technology. Effect of straw on microbial community composition and degradation efficiency of polycyclic aromatic hydrocarbons in sludge digester[J]. International Journal of Environmental Science and Technology, 2019, 16(12): 7973-7986. [11] 李新. 纤维素对污泥中多环芳烃厌氧生物降解的影响研究[D]. 贵州: 贵州大学, 2017. [12] CHANDRA R, TAKEUCHI H, HASEGAWA T. Methane production from lignocellulosic agricultural crop wastes: A review in context to second generation of biofuel production[J]. Renewable and Sustainable Energy Reviews, 2012, 16(3): 1462-1476. doi: 10.1016/j.rser.2011.11.035 [13] HENRY S M, GRBIC-GALIC D. Influence of endogenous and exogenous electron donors and trichloroethylene oxidation toxicity on trichloroethylene oxidation by methanotrophic cultures from a groundwater aquifer[J]. Applied and Environmental Microbiology, 1991, 57(1): 236-244. [14] MILTON L L, MILOS V N, KEITH D B. Analytical Chemistry of Polycyclic Aromatic Compounds[M]. New York: Academic Press, 1981. [15] LAHA S, LUTHY R G. Effects of nonionic surfactants on the solubilization and mineralization of phenanthrene in soil-water systems[J]. Biotechnology and Bioengineering, 1992, 40(11): 1367-1380. doi: 10.1002/(ISSN)1097-0290 [16] MCNALLY D L, MIHELCIC J R, LUEKING D R. Biodegradation of mixtures of polycyclic aromatic hydrocarbons under aerobic and nitrate-reducing conditions[J]. Chemosphere, 1999, 38(6): 1313-1321. doi: 10.1016/S0045-6535(98)00532-3 [17] RODRIGUES V D, TORRES T T, OTTOBONI L M M. Bacterial diversity assessment in soil of an active Brazilian copper mine using high-throughput sequencing of 16S rDNA amplicons[J]. Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2014, 106(5): 879-890. doi: 10.1007/s10482-014-0257-6 [18] MOLLER A K, SOBORG D A, Al SOUND W A, et al. Bacterial community structure in high-arctic snow and freshwater as revealed by pyrosequencing of 16S rRNA genes and cultivation[J]. Polar Research, 2013, 32(1): 1-11. [19] WANG Y, SHENG H F, HE Y, et al. Comparison of the levels of bacterial diversity in freshwater, intertidal wetland, and marine sediments by using millions of illumina tags[J]. Applied and Environmental Microbiology, 2012, 78(23): 8264-8271. doi: 10.1128/AEM.01821-12 [20] SCHLOSS P D, GEVERS D, WESTCOTT S L. Reducing the effects of PCR amplification and sequencing artifacts on 16S rRNA-based studies[J]. Plos One, 2011, 6(12): e27310. doi: 10.1371/journal.pone.0027310 [21] FOUTS D E, SEBASTIAN S, JANAKI P, et al. Next generation sequencing to define prokaryotic and fungal diversity in the Bovine Rumen[J]. Plos One, 2012, 7(11): e48289. doi: 10.1371/journal.pone.0048289 [22] OBERAUNER L, ZACHOW C, LACKNER S, et al. The ignored diversity: Complex bacterial communities in intensive care units revealed by 16S pyrosequencing[J]. Scientific Reports, 2013, 3: 1413-1424. doi: 10.1038/srep01413 [23] NELSON M C, MORROSON M, YU Z. A meta-analysis of the microbial diversity observed in anaerobic digesters[J]. Bioresource Technology, 2011, 102(4): 3730-3739. doi: 10.1016/j.biortech.2010.11.119 [24] RIVERE D, DESVIGNES V, PELLETIER E, et al. Towards the definition of a core of microorganisms involved in anaerobic digestion of sludge[J]. ISME Journal, 2009, 3(6): 700-714. doi: 10.1038/ismej.2009.2 [25] BURNS A S, PUGH C W, SEGID Y T, et al. Performance and microbial community dynamics of a sulfate-reducing bioreactor treating coal generated acid mine drainage[J]. Biodegradation, 2012, 23(3): 415-429. doi: 10.1007/s10532-011-9520-y [26] NIEPCERON M, MARTIN-LAURENT M, CRAMPON F, et al. GammaProteobacteria as a potential bioindicator of a multiple contamination by polycyclic aromatic hydrocarbons (PAHs) in agricultural soils[J]. Environmental Pollution, 2103, 180: 199-205. [27] ROGERS S W, ONG S K, MOORMAN T B. Mineralization of PAHs in coal-tar impacted aquifer sediments and associated microbial community structure investigated with FISH[J]. Chemosphere, 2007, 69: 1563-1573. doi: 10.1016/j.chemosphere.2007.05.058 [28] IMFELD G, ARAGONES C E, FETZER I, et al. Characterization of microbial communities in the aqueous phase of a constructed model wetland treating 1, 2-dichloroethene-contaminated groundwater[J]. FEMS Microbiology Ecology, 2010, 72(1): 74-88. doi: 10.1111/fem.2010.72.issue-1 [29] WANG L, ZHENG B, LEI K. Diversity and distribution of bacterial community in the coastal sediments of Bohai Bay, China[J]. Acta Oceanologica Sinica, 2015, 34(10): 122-131. doi: 10.1007/s13131-015-0719-3 [30] BALDWIN S A, KHOSHNOODI M, REZADEBASHI M, et al. The microbial community of a passive biochemical reactor treating arsenic, zinc and sulfate-rich seepage[J]. Frontiers in Bioengineering and Biotechnology, 2015, 3: 27. [31] TISCHER K, KLEINSTEUBER S, SCHLEINITZ K M, et al. Microbial communities along biogeochemical gradients in a hydrocarbon-contaminated aquifer[J]. Environmental Microbiology, 2013, 15(9): 2603-2615. doi: 10.1111/emi.2013.15.issue-9 [32] YAN Z S, HAO Z, WU H F, et al. Co-occurrence patterns of the microbial community in polycyclic aromatic hydrocarbon-contaminated riverine sediments[J]. Journal of Hazardous Materials, 2019, 367: 99-108. doi: 10.1016/j.jhazmat.2018.12.071