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四溴双酚A(TBBPA)是一种被广泛应用于电子电气产品生产的阻燃剂添加物. 在废弃电子产品或电器的拆解和回收过程中,添加型的TBBPA及重金属(包括铜、镉、锌等)易进入土壤环境中造成复合污染[1-3]. Wang等[1]的研究表明,电子垃圾回收站土壤中TBBPA、铜(Cu)、镉(Cd)、和锌(Zn)浓度分别高达0.65、2968、2088、11.5 mg·kg−1. 同时污染会向周边农田和河流底泥扩散,危害农业生产安全[4-5].
有研究报道了TBBPA在土壤、底泥、水体等环境中易发生生物降解转化作用,但较难发生彻底矿化[6]. 在厌氧微生物作用下,TBBPA脱溴形成双酚A(BPA),BPA在好氧条件下容易发生C链氧化断裂和苯环开环等反应,最终彻底矿化为CO2 [7-10]. 硝化污泥中的TBBPA降解和代谢则主要包括四个方面:1)经还原脱溴形成BPA;2)经氧化断裂形成各类极性代谢产物;3)经原位取代形成硝基衍生物;4)经甲基化生成持久性更强的甲基醚衍生物[11]. 在好氧土壤环境中TBBPA主要以生成极性代谢产物和甲基醚衍生物为主,其中甲基醚衍生物的生物毒性要低于TBBPA母体和其极性产物,是蚯蚓对抗TBBPA毒性的重要手段[12-13]. 此外,基于14C放射性示踪技术的研究发现土壤和底泥中30%—70%TBBPA会形成不可提取的结合残留,从而降低其环境暴露风险[6, 13-14].
有研究表明重金属可以通过直接或间接作用影响有机污染物的生物降解和吸附等行为:1)重金属离子可以和有机物上的羟基或氨基等活性官能团发生络合作用,直接影响有机污染物的形态和化学结构[15-17];2)重金属离子与土壤有机质发生络合或吸附作用,进而影响溶解态有机质团聚或竞争有机质上的吸附位,间接影响土壤中有机污染物的吸附行为 [18-21];3)重金属刺激或抑制土壤微生物活动,间接影响有机污染物的生物降解转化过程[22-25]. TBBPA作为一种含两个酚羟基且常与重金属同时进入土壤环境的污染物,有必要深入研究重金属离子对TBBPA降解转化行为的影响,以正确评价TBBPA在土壤环境的持久性和生物有效性.
因此,通过14C放射性示踪技术,研究了3种重金属(Cu、Cd和Zn)在不同浓度水平对两种典型土壤(乌栅土和红壤)中14C-TBBPA降解转化、矿化、不可提取态残留形成等环境行为的影响.
不同重金属对土壤中四溴双酚A环境归趋的影响
Effect of different heavy metals on the fate of TBBPA in two kinds of soil
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摘要: 四溴双酚A(TBBPA)和重金属的复合污染情况常见于电子电器拆解厂或回收站周边土壤,而重金属对TBBPA在土壤环境中的降解、转化和残留的影响尚不清晰. 本研究利用14C标记的TBBPA来探索不同浓度水平重金属(Cu、Cd和Zn)对两种土壤(红壤和乌栅土)中TBBPA降解转化、矿化、不可提取态残留形成等环境行为的影响. 经60 d培养,乌栅土中92.2% ± 0.5%的TBBPA被转化为不可提取态残留或代谢产物,其中7.2% ± 0.8%被彻底矿化为CO2;灭菌作用极大地抑制了乌栅土中TBBPA不可提取态残留的形成(由77.2%降至9.9%),表明土壤微生物在不可提取态残留的形成中起到关键作用. 而红壤中仅有9.9% ± 0.5%的TBBPA被转化成不可提取态残留,<0.5%被矿化为CO2,与灭菌对照组无显著差异. 当土壤重金属(>500 μmol·kg−1)存在时,乌栅土中TBBPA矿化和不可提取态残留形成率分别降低14%—78%和31%—86%,而可提取态TBBPA(即生物可利用态)增加0.5—4.4倍,其中水溶态残留增加0.3—1.5倍,进而增加TBBPA在土壤中的持久性和生物有效性. 随着重金属浓度增加,其对TBBPA降解转化的抑制效果也显著增强,在相同摩尔浓度下,不同重金属的抑制效应强度为Cd>Cu≈Zn;而在工业用地土壤重金属背景浓度范围内,Cu和Zn的抑制效应则远高于Cd. 本研究结果为正确评价重金属和TBBPA复合污染土壤中TBBPA的环境行为和风险提供了理论支撑.Abstract: The co-exist of tetrabromobisphenol A (TBBPA) and heavy metals is common in electrical and electronic dismantling plants or recycling stations, but the effect of heavy metals on the degradation and transformation of TBBPA in soil environment is still unknown. Therefore, we used 14C-labeled TBBPA to explore the effects of heavy metals (Cu, Cd and Zn) on the transformation, mineralization and bound residue formation of TBBPA in different soils with different heavy metal concentrations level. After 60 days of incubation, 92.2% ± 0.5% of TBBPA was converted into bound residues or metabolites, and only 7.2% ± 0.8% of TBBPA was mineralized into CO2. Sterilization greatly inhibited the formation of TBBPA bound residues (from 77.2% to 9.9%) in Wushan soil, indicating that soil microorganisms played a key role in the formation of TBBPA bound residues. Moreover, only 9.9% ± 0.5% of TBBPA was converted into bound residues in red soil, and less than 0.5% was mineralized, which was not significantly different from the sterilized control. With the presence of heavy metals (>500 μmol·kg−1), the mineralization and bound residues formation of TBBPA decreased by 14%—78% and 31%—86%, respectively. While, the extractable TBBPA (bioavailability) increased by 0.5—4.4 times, and the water-soluble residual increased by 0.3—1.5 times, resulting the increase of persistence and bioavailability of TBBPA in soil. With the increase of the concentration of heavy metals, the inhibition effect on TBBPA degradation and transformation was also significantly enhanced. Cd shown stronger effect than Zn and Cu under the same molar concentration. However, considering the background concentration of heavy metals in industrial land, the inhibition effect of Cu and Zn on TBBPA degradation and transformation was much higher than that of Cd. Our study provided theoretical support for correctly evaluating the persistence and effectiveness of TBBPA in heavy metal co-contaminated sites, such as electronic product recycling stations and waste sites.
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Key words:
- TBBPA /
- heavy metal /
- environmental fate /
- co-contamination
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表 1 土壤基本理化性质
Table 1. Physical and chemical properties of soil
种类
SoilpH 最大持水量/ %
Water holding capacity (dry soil weight)CEC / (cmol·kg−1) 全氮/ %
Total nitrogen有机质碳/ %
Organic carbon红壤 5.3 49.08 9.4 0.112 0.397 乌栅土 7.34 72.86 20.3 0.234 2.37 表 2 土壤重金属浓度及相应污染风险标准(mg·kg−1)
Table 2. Soil heavy metal concentrations and corresponding pollution risk criteria
重金属类型
Heavy metal红壤
Red soil乌栅土
Wushan soil农业地风险值a
Standard for agricultural land居住地风险值b
Standard for residential land工业地风险值b
Standard for industrial landCu 43.9 29.9 100 2000 18000 Zn 90.7 100 200 3500c 10000c Cd 0.046 0.183 0.3 20 65 备注:a 参考《土壤环境质量 农用地土壤污染风险管控标准(试行)》(GB15618—2018)农用地筛选值. According to the risk value of agricultural land in " Soil environmental quality Risk control standard for soil contamination of agricultural land. (Trial)" (GB15618-2018).
b 参考《土壤环境质量 建设用地土壤污染风险管控标准(试行)》(GB36600—2018)中的居住一类用地风险筛选值和二类工业用地风险筛选值. According to the risk value of residential land and industrial land in “Soil environmental quality Risk control standard for soil contamination of development land. (Trial)” (GB36600-2018).
c 参考《北京市场地土壤环境风险评价筛选值》(DB11/T 811—2011)中的居住地风险筛选值.
According to the risk value of residential land in “Screening Levels for Soil Environmental Risk Assessment of Sites” (DB11/T 811 -- 2011). -
[1] WANG J X, LIU L L, WANG J F, et al. Distribution of metals and brominated flame retardants (BFRs) in sediments, soils and plants from an informal e-waste dismantling site, South China [J]. Environmental Science and Pollution Research, 2015, 22(2): 1020-1033. doi: 10.1007/s11356-014-3399-1 [2] WU Y Y, LI Y Y, KANG D, et al. Tetrabromobisphenol A and heavy metal exposure via dust ingestion in an e-waste recycling region in Southeast China [J]. Science of the Total Environment, 2016, 541: 356-364. doi: 10.1016/j.scitotenv.2015.09.038 [3] LAW R J, ALLCHIN C R, de BOER J, et al. Levels and trends of brominated flame retardants in the European environment [J]. Chemosphere, 2006, 64(2): 187-208. doi: 10.1016/j.chemosphere.2005.12.007 [4] 夏炎, 韩伟立, 马安德. 广东省农耕土壤中四溴双酚A与六溴环十二烷的含量调查及其蓄积水平估算 [J]. 环境化学, 2017, 36(6): 1328-1334. XIA Y, HAN W L, MA A D. Contents, distribution and composition of tetrabromobisphenol A and hexabromocyclododecane in agricultural soils of Guangdong [J]. Environmental Chemistry, 2017, 36(6): 1328-1334(in Chinese).
[5] 吴玉丽, 肖羽堂, 王冠平, 等. 多溴联苯醚、六溴环十二烷和四溴双酚A在环境中污染现状的研究进展 [J]. 环境化学, 2021, 40(2): 384-403. WU Y L, XIAO Y T, WANG G P, et al. Research progress on status of environmental pollutions of polybrominated diphenyl ethers, hexabromocyclodocane, and tetrabromobisphenol A: A review [J]. Environmental Chemistry, 2021, 40(2): 384-403(in Chinese).
[6] 蔡蕊, 王文姬, 许航, 等. 四溴双酚A在土壤中的降解转化及残留研究进展 [J]. 环境化学, 2021, 40(1): 102-110. CAI R, WANG W J, XU H, et al. Degradation, transformation, and residue formation of tetrabromobisphenol A ( TBBPA) in soil: A review [J]. Environmental Chemistry, 2021, 40(1): 102-110(in Chinese).
[7] VOORDECKERS J W, FENNELL D E, JONES K, et al. Anaerobic biotransformation of tetrabromobisphenol A, tetrachlorobisphenol A, and bisphenol A in estuarine sediments [J]. Environmental Science & Technology, 2002, 36(4): 696-701. [8] HU F, PAN L, XIU M, JIN Q, et al. Bioaccumulation and detoxification responses in the scallop Chlamys farreri exposed to tetrabromobisphenol A (TBBPA) [J]. Environmental Toxicology and Pharmacology, 2015, 39(3): 997-1007. doi: 10.1016/j.etap.2015.03.006 [9] LIU J, WANG Y F, JIANG B Q, et al. Degradation, metabolism, and bound-residue formation and release of Tetrabromobisphenol A in soil during sequential anoxic-oxic incubation [J]. Environmental Science & Technology, 2013, 47(15): 8348-8354. [10] 杨书娴, 胡星. 新型好氧W1-2菌株降解四溴双酚A的性能 [J]. 上海大学学报(自然科学版), 2022, 28(1): 57-66. YANG S X, HU X. Degradation characteristics of biodegradation of tetrabromobisphenol A by the novel arerobic strain W1-2 [J]. Journal of Shanghai University (Natural Science Edition), 2022, 28(1): 57-66(in Chinese).
[11] LI F J, WANG J J, NASTOLD P, et al. Fate and metabolism of tetrabromobisphenol A in soil slurries without and with the amendment with the alkylphenol degrading bacterium Sphingomonas sp. strain TTNP3 [J]. Environmental Pollution (Barking, Essex:1987), 2014, 193: 181-188. doi: 10.1016/j.envpol.2014.06.030 [12] GU J Q, CHEN X, WANG Y F, et al. Bioaccumulation, physiological distribution, and biotransformation of tetrabromobisphenol a (TBBPA) in the geophagous earthworm Metaphire guillelmi - hint for detoxification strategy [J]. Journal of Hazardous Materials, 2020, 388: 122027. doi: 10.1016/j.jhazmat.2020.122027 [13] GU J Q, JING Y Y, MA Y N, et al. Effects of the earthworm Metaphire guillelmi on the mineralization, metabolism, and bound-residue formation of tetrabromobisphenol A (TBBPA) in soil [J]. The Science of the Total Environment, 2017, 595: 528-536. doi: 10.1016/j.scitotenv.2017.03.273 [14] SUN F F, KOLVENBACH B A, NASTOLD P, et al. Degradation and metabolism of tetrabromobisphenol A (TBBPA) in submerged soil and soil-plant systems. [J]. Environmental Science & Technology, 2014, 48(24): 14291-14299. [15] SCHRÖEDER P, LYUBENOVA L, HUBER C. Do heavy metals and metalloids influence the detoxification of organic xenobiotics in plants? [J]. Environmental Science and Pollution Research International, 2009, 16(7): 795-804. doi: 10.1007/s11356-009-0168-7 [16] TAN Y Y, GUO Y, GU X Y, et al. Effects of metal cations and fulvic acid on the adsorption of ciprofloxacin onto goethite [J]. Environmental Science and Pollution Research, 2015, 22(1): 609-617. doi: 10.1007/s11356-014-3351-4 [17] ZHAO Y P, TAN Y Y, GUO Y, et al. Interactions of tetracycline with Cd (II), Cu (II) and Pb (II) and their cosorption behavior in soils [J]. Environmental Pollution, 2013, 180: 206-213. doi: 10.1016/j.envpol.2013.05.043 [18] LU M, ZHANG Z Z, WANG J X, et al. Interaction of heavy metals and Pyrene on their fates in soil and tall fescue (Festuca arundinacea) [J]. Environmental Science & Technology, 2014, 48(2): 1158-1165. [19] LUO L, ZHANG S Z, CHRISTIE P. New insights into the influence of heavy metals on phenanthrene sorption in soils [J]. Environmental Science & Technology, 2010, 44(20): 7846-7851. [20] ZHANG W H, ZHENG J, ZHENG P, et al. The roles of humic substances in the interactions of phenanthrene and heavy metals on the bentonite surface [J]. Journal of Soils and Sediments, 2015, 15(7): 1463-1472. doi: 10.1007/s11368-015-1112-8 [21] 孔颖, 左翔之, 易鹏, 等. 天然有机质的性质分析及其与土壤矿物和外源污染物相互作用研究进展 [J]. 环境化学, 2021, 40(9): 2715-2726. KONG Y, ZUO X Z, YI P, et al. Research progress on analysis of the properties of natural organic matter and its interaction with soil minerals and exogenous pollutants [J]. Environmental Chemistry, 2021, 40(9): 2715-2726(in Chinese).
[22] ZHANG H, DANG Z, YI X Y, et al. Evaluation of dissipation mechanisms for pyrene by maize (Zea Mays L. ) in cadmium co-contaminated soil [J]. Global Nest Journal, 2009, 11(4): 487-496. [23] WANG Y H, LI M J, LIU Z W, et al. Interactions between Pyrene and heavy metals and their fates in a soil-maize (Zea mays L. ) system: Perspectives from the root physiological functions and rhizosphere microbial community [J]. Environmental Pollution, 2021, 287: 117616. doi: 10.1016/j.envpol.2021.117616 [24] 陆雅婕, 吴笛, 尹颖, 等. 重金属和溴代阻燃剂复合污染对小白菜的生物效应 [J]. 南京大学学报(自然科学), 2018, 54(1): 196-204. LU Y J, WU D, YIN Y, et al. Combined effect of heavy metals and bromine flame retardants for pakchoi [J]. Journal of Nanjing University (Natural Science), 2018, 54(1): 196-204(in Chinese).
[25] 陈欣瑶, 杨惠子, 陈楸健, 等. 重金属胁迫下不同区域土壤的生态功能稳定性与其微生物群落结构的相关性 [J]. 环境化学, 2017, 36(2): 356-364. CHEN X Y, YANG H Z, CHEN Q J, et al. Correlation between microbial community structure and soil ecosystem functional stability under heavy metal stress [J]. Environmental Chemistry, 2017, 36(2): 356-364(in Chinese).
[26] YU X S, LIU Y, LOU J, et al. Determination of water- and methanol-extractable pentachlorophenol in soils using vortex-assisted liquid-liquid extraction and gas chromatography [J]. Chinese Journal of Analytical Chemistry, 2015, 43(9): 1389-1394. doi: 10.1016/S1872-2040(15)60861-1 [27] LI F J, JIANG B Q, NASTOLD P, et al. Enhanced transformation of tetrabromobisphenol A by nitrifiers in nitrifying activated sludge [J]. Environmental Science & Technology, 2015, 49(7): 4283-4292. [28] LI F J, WANG J J, JIANG B Q, et al. Fate of tetrabromobisphenol A (TBBPA) and formation of ester- and ether-linked bound residues in an oxic sandy soil [J]. Environmental Science & Technology, 2015, 49(21): 12758-12765. [29] 郭碧林, 陈效民, 景峰, 等. 外源Cd胁迫对红壤性水稻土微生物量碳氮及酶活性的影响 [J]. 农业环境科学学报, 2018, 37(9): 1850-1855. GUO B L, CHEN X M, JING F, et al. Effects of exogenous cadmium on microbial biomass and enzyme activity in red paddy soil [J]. Journal of Agro-Environment Science, 2018, 37(9): 1850-1855(in Chinese).
[30] HE G H, WU J C, LIU Q, et al. Microbial and enzyme properties of acidic red soils under aluminum stress [J]. Fresenius Environmental Bulletin, 2012, 21(9): 2818-2825. [31] HAO S F, WANG P Y, GE F, et al. Enhanced Lead (Pb) immobilization in red soil by phosphate solubilizing fungi associated with tricalcium phosphate influencing microbial community composition and Pb translocation in Lactuca sativa L[J]. Journal of Hazardous Materials, 2022, 424(Pt D): 127720. [32] GU Y, SUN X B, LIU Y D. Biosorption and biodegradation of bisphenol A in an activated sludge system [J]. Research on Chemical Intermediates, 2016, 42(5): 4289-4301. doi: 10.1007/s11164-015-2274-0 [33] WANG M Q, YIN H, PENG H, et al. Degradation of 2, 2', 4, 4'-tetrabromodiphenyl ether by Pycnoporus sanguineus in the presence of copper ions [J]. Journal of Environmental Sciences, 2019, 83: 133-143. doi: 10.1016/j.jes.2019.03.020 [34] TONG F, GU X Y, GU C, et al. Insights into tetrabromobisphenol A adsorption onto soils: Effects of soil components and environmental factors [J]. Science of The Total Environment, 2015, 536: 582-588. doi: 10.1016/j.scitotenv.2015.07.063 [35] LI J H, ZHOU B X, SHAO J H, et al. Influence of the presence of heavy metals and surface-active compounds on the sorption of bisphenol A to sediment [J]. Chemosphere, 2007, 68(7): 1298-1303. doi: 10.1016/j.chemosphere.2007.01.045 [36] CHEN X, GU X Y, ZHAO X P, et al. Species-dependent effects of earthworms on the fates and bioavailability of tetrabromobisphenol A and cadmium coexisted in soils [J]. The Science of the Total Environment, 2019, 658: 1416-1422. doi: 10.1016/j.scitotenv.2018.12.196 [37] MA Y N, ZHAO Y Y, WANG Y F, et al. Effects of Cu2+ and humic acids on degradation and fate of TBBPA in pure culture of Pseudomonas sp strain CDT [J]. Journal of Environmental Sciences, 2017, 62: 60-67. doi: 10.1016/j.jes.2017.07.012 [38] HUANG Z L, JIANG L F, LU W S, et al. Elsholtzia splendens promotes phenanthrene and polychlorinated biphenyl degradation under Cu stress through enrichment of microbial degraders [J]. Journal of Hazardous Materials, 2022, 438: 129492. doi: 10.1016/j.jhazmat.2022.129492