-
邻苯二甲酸酯(phthalate esters, PAEs)又称酞酸酯,是一类重要的合成有机物,被广泛应用于塑料制造[1],常用作涂料、润滑剂、粘合剂、杀虫剂、包装和化妆品的添加剂[2]。有文献报道了国内23个城市的90个自来水厂141个水源水样中均检出了邻苯二甲酸单酯(MPAEs)[3],邻苯二甲酸二丁酯(DBP)是PAEs中的一种,在增塑剂中应用最为广泛,极易从塑料中释放到环境中[4-5],是一种环境激素类物质,具有致癌、致畸与致突变作用[6-8],因此,开展PAEs此类污染物在不同环境中的降解研究对于生态环境安全保障尤为重要。
目前,对DBP污染的生物降解研究主要集中在高效降解菌的筛选、驯化及降解机理等方面[9-10],游离态菌株在实际应用中存在降解周期长、菌体易流失、环境耐受性差等问题,因此,国内外学者利用固定化微生物技术解决生物降解的缺陷,已应用在处理生活废水[11]、池塘模拟废水[12]、难降解有机废水[13-14]等水污染治理方面。为了得到具有高固定化强度和高微生物活性的固定化系统,可选择两种及以上的固定化材料结合起来的复合固定化法,例如:采用聚乙烯醇和海藻酸钠为包埋材料、活性炭为吸附材料、CaCl2的饱和硼酸溶液为交联剂,同时,负载较强生物活性的高效降解混合菌势必会提高生物解吸的效率,最终获得对底物优异的降解性能[15],具有较强的实际应用性。
本研究以DBP为目标污染物,开展了DBP降解混合菌(以下简称DP3)的包埋-吸附-交联固定化条件优化及降解特性研究,以聚乙烯醇(PVA)和海藻酸钠(SA)为包埋材料、活性炭为吸附材料,CaCl2的饱和硼酸溶液为交联剂,采用正交试验确定最佳固定化制备条件,并以游离态混合菌为对照,研究了pH值、盐度、DBP浓度对固定化混合菌降解性能的影响,研究结果可为DBP降解菌在环境修复中的应用提供理论依据和技术支持。
复合固定化混合菌DP3去除邻苯二甲酸二丁酯
The removal of dibutyl phthalate by immobilization of mixed bacteria DP3
-
摘要: 为了提高邻苯二甲酸二丁酯(DBP)的降解效率,采用正交法开展了“包埋-吸附-交联”复合固定化法固定混合菌DP3制备条件的优化试验,研究了环境因素对固定化混合菌DP3降解DBP性能的影响,并对其去除DBP过程进行初步研究。结果表明,固定化混合菌DP3的最佳制备条件为聚乙烯醇(PVA)质量分数10%、海藻酸钠(SA)质量分数2%、活性炭(AC)质量分数3%、CaCl2质量分数1%,1 d内对DBP降解效果可达到98.84%,与游离态混合菌相比,其降解率提高35.11%;固定化混合菌DP3对不同浓度DBP去除效率显著优于空白凝胶球;其对模拟人工污水中DBP的降解率1 d即可达98.03%。当pH值在4—10、NaCl浓度在5—100 g·L−1、底物浓度在10—200 mg·L−1时,固定化混合菌DP3对底物表现优异的降解性能,降解率显著优于游离态;固定化混合菌DP3对底物降解符合一阶动力学方程,具有良好的重复稳定性,研究结果可为固定化混合菌在环境中降解DBP的应用提供理论依据。
-
关键词:
- 邻苯二甲酸二丁酯(DBP)降解 /
- 固定化 /
- 混合菌DP3
Abstract: In order to improve the degradation efficiency of dibutyl phthalate (DBP), this study used an orthogonal design across a combined “embedding-adsorption-crosslinking” aspect to optimize the preparation conditions for the immobilization of mixed bacteria DP3, and then investigated the DBP degradation efficiencies by the immobilized DP3 under different environmental conditions. Also the removal process of DBP by the immobilized DP3 was preliminarily studied. The established formula for the preparation of the immobilized mixed bacteria DP3 was addressed with mass fractions and the proportions of polyvinyl alcohol (PVA), sodium alginate (SA), activated carbon (AC), and calcium chloride (CaCl2) were 10%, 2%, 3%, and 1%, respectively. The degradation efficiency of the immobilized mixed bacteria DP3 was 35.11% higher than the free mixed bacteria and reached to 98.84% in 1 d. In addition, the degradation efficiency of the immobilized DP3 were demonstrated to be higher than the blank gel spheres over different DBP concentrations, and the DBP degradation efficiency of artificial sewage wastewater reached 98.03% in 1 day. Under the condition of pH 4–10, NaCl concentration of 5–100 g·L−1, DBP concentration of 10–200 mg·L−1, the immobilized mixed bacteria DP3 showed significantly higher degradation efficiency comparing with the free mixed bacteria. Moreover, the degradation curve of DBP was well fitted with a first-order kinetics stably and repeatedly. This study provided evidence for using immobilized mixed bacteria to remove DBP under actual conditions.-
Key words:
- Dibutyl phthalate, degradation /
- immobilization /
- mixed bacteria
-
表 1 正交试验设计
Table 1. Orthogonal design of immobilization
水平
Level因素Factor A:PVA/% B:SA/% C:AC/% D:CaCl2 /% 1 8 1 1 1 2 10 2 2 2 3 12 3 3 3 表 2 固定化条件优化正交试验结果
Table 2. Orthogonal experimental results
序号
Number因素Factor DBP去除率/%
DBP Removal ratePVA SA AC CaCl2 1 1 1 1 1 88.57 2 1 2 2 2 93.88 3 1 3 3 3 95.62 4 2 1 2 3 95.73 5 2 2 3 1 99.86 6 2 3 1 2 91.58 7 3 1 3 2 95.77 8 3 2 1 3 90.15 9 3 3 2 1 94.33 Ⅰj 92.69 93.36 90.10 94.25 Ⅱj 95.72 94.63 94.65 93.74 Ⅲj 93.42 93.84 97.08 93.83 Rj 3.03 1.27 6.98 0.51 表 3 固定化DP3的DBP降解动力学方程
Table 3. Equation of DBP degradation kinetics by immobilized DP3
名称
Name初始浓度/(mg·L−1)
Initial concentration动力学方程
Degradation kinetics动力学参数/h−1
Kinetic parametert1/2/h R2 10 lnC=−0.1859t+2.3026 0.1859 3.7284 0.8022 20 lnC=−0.1869t+2.9957 0.1869 3.7089 0.8008 固定化DP3 50 lnC=−0.1540t+3.9120 0.1540 4.5014 0.8487 100 lnC=−0.0977t+4.6052 0.0977 7.0951 0.9283 200 lnC=−0.0922t+5.2983 0.0922 7.5175 0.9353 10 lnC=−0.0426t+2.3026 0.0426 16.2671 0.8869 20 lnC=−0.0352t+2.9957 0.0352 19.7153 0.9181 游离态DP3 50 lnC=−0.0105t+3.9120 0.0105 65.9889 0.9916 100 lnC=−0.0060t+4.6052 0.0060 114.8983 0.9972 200 lnC=−0.0037t+5.2983 0.0037 184.4257 0.9989 -
[1] 黄艳, 卞战强, 田向红, 等. 环境中邻苯二甲酸酯类化合物降解技术研究进展[J]. 环境与健康杂志, 2010, 27 (7): 654-657. HUANG Y, BIAN Z Q, TIAN X H, et al. Progress of degradation techniques of environmental phthalic acid esters[J]. Journal of Environment and Health, 2010, 27(7): 654-657(in Chinese).
[2] ROSLEV P, VORKAMP K, AARUP J, et al. Degradation of phthalate esters in an activated sludge wastewater treatment plant [J]. Water Research, 2007, 41(5): 969-976. doi: 10.1016/j.watres.2006.11.049 [3] 丁梦雨, 康启越, 张释义, 等. 全国23个城市水源水中邻苯二甲酸酯代谢物浓度调查 [J]. 中国环境科学, 2019, 39(10): 4205-4211. doi: 10.3969/j.issn.1000-6923.2019.10.021 DING M Y, KANG Q Y, ZHANG S Y, et al. National survey of phthalate metabolites in drinking source water of 23 cities in China [J]. China Environmental Science, 2019, 39(10): 4205-4211(in Chinese). doi: 10.3969/j.issn.1000-6923.2019.10.021
[4] LIANG D W, ZHANG T, FANG H H, et al. Phthalates biodegradation in the environment [J]. Applied Microbiology & Biotechnology, 2008, 80(2): 183-198. [5] NAHURIRA R, REN L, SONG J, et al. Degradation of di(2-Ethylhexyl) phthalate by a novel Gordonia alkanivorans strainYC-RL2 [J]. Current Microbiology, 2017, 74(3): 1-11. [6] 杨婧. 邻苯二甲酸酯降解菌的降解特性与土壤应用研究[D]. 广州: 华南理工大学, 2018. YANG J. Characterization of phthalate-degrading bacterial strain and its application in phthalate-contaminated soil[D]. Guangzhou: South China University of Technology, 2018(in Chinese).
[7] 裴小强. 室内空气中邻苯二甲酸酯的污染特征及健康风险[D]. 杭州: 浙江大学, 2013. PEI X Q. Pollution characteristics and health risk of phthalates in indoor air[D]. Hangzhou: Zhejiang University, 2013(in Chinese).
[8] 唐文娟. PAEs 降解菌筛选及一株根瘤菌降解特性与基因组学分析的研究[D]. 上海: 华东理工大学, 2016. TANG W J. Isolation of phthalate esters degrading strains and biodegradation characteristics and whole genome analyses of Rhizobium sp. LMB-1[D]. Shanghai: South China University of Technology, 2016(in Chinese).
[9] 高静静, 陈丽玮, 王宜青, 等. 一株邻苯二甲酸二(2-乙基己基)酯(DEHP)高效降解菌的筛选及其降解特性 [J]. 环境化学, 2016, 35(11): 2362-2369. doi: 10.7524/j.issn.0254-6108.2016.11.2016040103 GAO J J, CHEN L W, WANG Y Q, et al. Screening and degradation characteristics of a highly efficient degrading bacteria of Di(2-ethylhexyl) phthalate (DEHP) [J]. Environmental Chemistry, 2016, 35(11): 2362-2369(in Chinese). doi: 10.7524/j.issn.0254-6108.2016.11.2016040103
[10] LI J, GU J D, PAN L. Transformation of dimethyl phthalate, dimethyl isophthalate and dimethyl terephthalate by Rhodococcus rubber, Sa and modeling the processes using the modified Gompertz model [J]. International Biodeterioration & Biodegradation, 2005, 55(3): 223-232. [11] 胡俊. 固定化微球菌降解废水中邻苯二甲酸酯的研究[D]. 北京: 中国地质大学, 2014. HU J. Biodegradation of di-n-butyl phthalate in wastewater by immobilized Micrococcus sp.[D]. Beijing: China University of Geosciences, 2014 (in Chinese).
[12] 颜婷婷. 固定化微生物处理邻苯二甲酸酯类废水的研究[D]. 合肥: 安徽农业大学, 2007. YANT T, Treatineni of PAEs wastewater by immobilized microbial cells[D]. Hefei: Anhui Agricultural University, 2007(in Chinese).
[13] EL-NAAS M H, AL-ZUHAIR S, MAKHLOUF S. Continuous biodegradation of phenol in a spouted bed bioreactor (SBBR) [J]. Chemical Engineering Journal, 2010, 160(2): 565-570. doi: 10.1016/j.cej.2010.03.068 [14] QIAO L, WEN D L, WANG J L. Biodegradation of pyridine by Paracoccus sp. KT-5 immobilized on bamboo-based activated carbon [J]. Bioresource Technology, 2010, 101(14): 5229-5234. doi: 10.1016/j.biortech.2010.02.059 [15] 李婧, 党志, 郭楚玲, 等. 复合固定化法固定微生物去除芘 [J]. 环境化学, 2012, 31(7): 1036-1042. LI J, DANG Z, GUO C L. Pyrene was removed by immobilization of microorganisms [J]. Environmental Chemistry, 2012, 31(7): 1036-1042(in Chinese).
[16] 李容榛, 李成, 赵暹, 等. 一株高效邻苯二甲酸二丁酯降解菌的筛选、鉴定及其降解特性研究 [J]. 环境化学, 2019, 38(10): 2274-2282. doi: 10.7524/j.issn.0254-6108.2018111502 LI R Z, LI C, ZHAO X, et al. Isolation and identification of a highly efficient DBP degrading bacteria and its degradation characteristics [J]. Environmental Chemistry, 2019, 38(10): 2274-2282(in Chinese). doi: 10.7524/j.issn.0254-6108.2018111502
[17] 邱东亚, 薛屏. 聚乙烯醇-壳聚糖复合物包埋微生物高效降解水中苯酚的研究 [J]. 化学研究与应用, 2017, 29(9): 1339-1345. doi: 10.3969/j.issn.1004-1656.2017.09.011 QIU D Y, XU P. Microorganism entrapped using polyvinyl alcohol-chitosan composite for efficient degradation of phenol in water [J]. Chemical Research and Application, 2017, 29(9): 1339-1345(in Chinese). doi: 10.3969/j.issn.1004-1656.2017.09.011
[18] ZHU X M, CHEN B L, ZHU L Z, et al. Effects and mechanisms of biochar-microbe interactions in soil improvement and pollution remediation: A review [J]. Environmental Pollution, 2017, 227: 98-115. doi: 10.1016/j.envpol.2017.04.032 [19] 叶正芳, 倪晋仁. 污水处理的固定化微生物与游离微生物性能的比较 [J]. 应用基础与工程科学学报, 2002, 10(4): 325-331. doi: 10.3969/j.issn.1005-0930.2002.04.001 YE Z F, NI J R. Comparison of immobilized microorganism and free microorganism in sewage treatment [J]. Journal of Basic Science and Engineering, 2002, 10(4): 325-331(in Chinese). doi: 10.3969/j.issn.1005-0930.2002.04.001
[20] 李欣, 凌婉婷, 刘静娴, 等. 固定化菌剂对污水和牛粪中雌二醇和己烯雌酚的去除作用 [J]. 环境科学, 2015, 36(7): 2581-2590. LI X, LING W T, LIU J X, et al. Immobilization of Estrogen-degrading Bacteria to remove the 17β-estradiol and Diethylstilbestrol from Polluted Water and Cow Dung [J]. Environmental Science, 2015, 36(7): 2581-2590(in Chinese).
[21] 郝红红, 陈浚, 程鳌, 等. 一株好氧反硝化菌的筛选鉴定及固定化研究 [J]. 环境科学学报, 2013, 33(11): 102-109. HAO H H, CHEN J, CHENG A, et al. Isolation and identification of an aerobic denitrifying bacteria and its immobilization characteristics [J]. Acta Scientiae Circumstantiae, 2013, 33(11): 102-109(in Chinese).
[22] 李瑞, 于超, 丁裕斌, 等. 增塑剂邻苯二甲酸二(2-乙基己基)酯(DEHP)对绒毛外滋养层细胞侵袭和迁移的影响 [J]. 中国细胞生学学报, 2011, 33(12): 22-29. LI R, YU C, DING Y B, et al. Effect of plasticizer Di(2-ethylhexyl) phthalate (DEHP) on invasion and migration of trophoblast cells outside villi [J]. Chinese Journal of Cell Biology, 2011, 33(12): 22-29(in Chinese).
[23] 刘文斌, 张海涛, 杨海君, 等. 辛基酚聚氧乙烯醚高效降解混合菌L9的固定化及其条件优化 [J]. 环境工程学报, 2016, 10(10): 6056-6064. doi: 10.12030/j.cjee.201603195 LIU W B, ZHANG H T, YANG H J, et al. Immobilization of mixed bacteria L9’s degrading octylphenol ethoxylates and its optimization [J]. Chinese Journal of Environmental Engineering, 2016, 10(10): 6056-6064(in Chinese). doi: 10.12030/j.cjee.201603195
[24] 路俊玲, 彭宇科, 陈旭, 等. 包埋法固定化对邻苯二甲酸酯降解菌功能的影响 [J]. 南京大学学报(自然科学), 2017, 53(2): 309-315. LU J L, PENG Y K, CHEN X, et al. Effects of immobilization on the activity of the phthalic acid esters degradation bacteria [J]. Journal of Nanjing University(Natural Science), 2017, 53(2): 309-315(in Chinese).
[25] TALLUR P N, MEGADI V B, NINNEKAR H Z. Biodegradation of p-cresol by immobilized cells of Bacillus sp. strain PHN 1 [J]. Biodegradation, 2009, 20(1): 79-83. doi: 10.1007/s10532-008-9201-7