Page 38 - 《广西植物》2024年第10期
P. 38
1 8 4 0 广 西 植 物 44 卷
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Abstract: The effects of pHꎬ temperatureꎬ initial Cr concentrationꎬ adsorbent dosageꎬ timeꎬ and other factors on the
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adsorption capacity of Cr were examined by the single factor test method using inactivated Bacillus cereus J01 strain as
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biological adsorbent in order to investigate the adsorption performance of Cr by endophytic bacterium Bacillus cereus J01
from Leersia hexandra Swartz. The kineticꎬ thermodynamicꎬ and isothermal adsorption processes were analyzed. Infrared
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spectroscopy was used to provide a preliminary analysis of the Cr adsorption mechanism. The results were as follows:
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(1) In the reaction system of 50 mLꎬ inactivated Bacillus cereus J01 reached the best adsorption performance on Cr
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when pH value was 6ꎬ temperature was 40 ℃ꎬ initial concentration of Cr was 150 mgL ꎬ adsorbent dosage was 0.2 g
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and adsorption time was 12 h. The equilibrium adsorption capacity was 34.30 mgg and the removal rate of Cr was
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91.60%. (2) The Langmuir isothermal adsorption model could better simulate the adsorption of Cr by inactivated
Bacillus cereus J01. The adsorption process was more similar to monolayer adsorption. (3) The adsorption kinetics
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analysis showed that the adsorption of inactivated Bacillus cereus J01 on Cr was more consistent with quasi ̄second ̄order
kinetic rate equation. (4) Thermodynamic analysis of adsorption showed that at 40 ℃ꎬ △Gꎬ △H and △S were -2.609
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kJmol ꎬ 61.792 kJmol and 206.11 Jmol ꎬ respectively. The adsorption process was spontaneous at 40 ℃. (5)
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The results of infrared spectroscopy showed that the adsorption of inactivated Bacillus cereus J01 on Cr could be
attributed to the effects of aminoꎬ hydroxyl and carbonyl groups in the cell components. The results show that the
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inactivated bacteria of this bacterium has strong adsorption capacity for Cr ꎬ and has good application potential in the
treatment of environmental chromium pollution.
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Key words: Bacillus cereusꎬ adsorptionꎬ Cr ꎬ Leersia hexandraꎬ endophytic bacterium
重金属污染是世界上最受关注的环境问题之 等(2011)从皮革铬鞣、复鞣污泥等处分离纯化出丝
一ꎬ对环境和人类有着各种影响ꎮ 铬是对人体具有 孢酵母 TP、蜡样芽孢杆菌 XB、蜡样芽孢杆菌 MY 和
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致癌和致突变作用的典型重金属之一 ( Mishra & 土曲霉 TQ 等菌株ꎬ其吸附 Cr 的最大吸附量分别
Bharagavaꎬ 2016)ꎮ 为适应对废水排放要求越发苛 为 26.8、19.3、16.9、21.4 mgg ꎻ海洋解木糖赖氨酸
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刻的限制形势ꎬ许多技术被用来脱除废水中的铬ꎬ 芽孢杆菌 ( Lysinibacillus xylanilyticus sp. JZ008) 对
如微滤技术、吸附法、化学沉淀法、萃取法和电解法 Cr 的吸附量约为 0.4 mgg 湿菌体( 林梵宇等ꎬ
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(Fu & Wangꎬ 2011)ꎮ 其中ꎬ吸附法性价比最高ꎬ而 2018)ꎻ短乳杆菌( Lactobacillus brevis) 对水溶液中
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传统吸附法存在着明显缺点ꎬ如化学药剂用量大、 Cr 的 最 大 吸 附 量 约 为 32 mg g ( 代 启 虎 等ꎬ
成本高、需要后期进行脱水处理、金属去除不彻底 2019)ꎻ米曲霉 AS3.951 干菌体对 Cr 的吸附量为
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或者易产生二次污染等(Joseph et al.ꎬ 2019)ꎮ 近年 6.66 mgg (吴俊贤ꎬ2017)ꎮ 现有报道的 Cr 微生
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来ꎬ微生物吸附法因具有成本低廉、易于处理、可获 物吸附剂存在种类较少、吸附量较低、吸附速率慢
得性广泛、资源丰富和与金属结合能力强等优点而 等问题ꎮ 因此ꎬ亟需寻找新的高效吸附 Cr 的微生
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受到了人们的重视(Vendruscolo et al.ꎬ 2017ꎻ Wei et
物ꎬ以补充和完善微生物法修复铬污染的菌源ꎮ
al.ꎬ 2018)ꎮ 应用的微生物包括微藻( Daneshvar et 重金属超积累植物 ( hyperaccumulator) ( 陈一
al.ꎬ 2019ꎻ Pradhan et al.ꎬ 2019)、真菌( de Rossi et 萍ꎬ2008)是一类能超量吸收重金属且使其富集的
al.ꎬ 2018ꎻ Shi et al.ꎬ 2019) 和 细 菌 ( Ma et al.ꎬ
特殊植物ꎬ如东南景天( 杨肖娥等ꎬ2002ꎻ 何冰等ꎬ
2018)ꎮ 铬的形态主要表现为三价铬(Cr ) 和六价 2014)、 堇 叶 碎 米 荠 ( 郭 松 明 等ꎬ 2022)、 Nopalea
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铬[Cr(Ⅵ)]ꎮ 与 Cr(Ⅵ)相比ꎬ尽管 Cr 毒性较弱ꎬ cochenillifera( Adki et al.ꎬ 2013)、野薄荷( 高洁等ꎬ
但 Cr 所造成的伤害同样不可忽视ꎬ若吸入的氧化 2012)等ꎬ在重金属污染修复中的应用日益广泛ꎮ
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铬浓度为 0.012~ 0.033 mgm 时ꎬ可诱发鼻出血、 近年来ꎬ为了弥补植物修复易受生长周期、地理环
鼻黏膜萎缩和鼻中隔穿孔ꎬ甚至严重时会引起肺癌 境等影响的不足ꎬ植物内生菌的应用开始得到研究
(钟雅洁等ꎬ2007ꎻ 霍小平和刘存海ꎬ2009)ꎮ 目前ꎬ 者的重视ꎮ 植物内生菌是指一类在其部分或全部
在铬污染微生物修复领域ꎬ大多数研究集中在 Cr 生活史中存活于健康植物组织内部ꎬ并且不使宿主
(Ⅵ)的吸附或还原ꎬ对 Cr 的去除研究不多ꎮ 李欣 植物 表 现 出 明 显 感 染 症 状 的 微 生 物 ( Wilsonꎬ
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