Centre for Agroecology Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton on Dunsmore, CV8 3LG, UK.
Centre for Agroecology Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton on Dunsmore, CV8 3LG, UK.
Sci Total Environ. 2020 Nov 1;741:140411. doi: 10.1016/j.scitotenv.2020.140411. Epub 2020 Jun 20.
This study reports on the evaluation of the equilibrium, thermodynamics and kinetics of mercury (II) biosorption using a living biofilm, developed on a nonwoven polypropylene and polyethylene geotextile, typically used within the structure of Sustainable Drainage System (SuDS) devices. Batch biosorption assays were carried out with variables such as pH, initial concentrations, contact time, temperature and biofilm incubation time. Langmuir, Freundlich and Dubinin Radushkevich (D-R) models were applied to the equilibrium data which revealed the maximum biosorption capacities and efficiencies at pH 5.5 with a contact time of 120 min at 25 °C. With 20 mg L added Hg (II), living biofilm samples with incubation times of 1, 7, 14, 21 and 28 days, biosorption values were 101.31 (55.72%), 24.41 (67.12%), 16.81 (61.37%), 9.70 (62.57%) and 13.34 (65.38%) mg g, respectively. Free mean biosorption energy from the D-R model was between 2.24 and 2.36 kJ mol for all biofilm development incubation times, that revealed the physical biosorption mechanism for Hg(II). The thermodynamic studies showed that the Hg(II) biosorption of living biofilm was thermodynamically feasible and had a spontaneous and exothermic nature. Kinetic parameters revealed that Hg(II) biosorption onto living biofilm had a good correlation with a pseudo second-order kinetic model. FTIR spectra after biosorption suggested that amine, hydroxyl and carboxyl groups were the main functional groups available and responsible for Hg(II) biosorption onto living biofilm. Experimental data suggested that a living biofilm developed on a nonwoven polypropylene and polyethylene geotextile can be efficient in the removal of mercury ions from contaminated urban and industrial runoff.
本研究报告了使用无纺聚丙烯和聚乙烯土工织物上的生物膜评估汞（II）生物吸附的平衡、热力学和动力学，该土工织物通常用于可持续排水系统（SuDS）装置的结构内。进行了批次生物吸附实验，变量包括 pH 值、初始浓度、接触时间、温度和生物膜孵育时间。将 Langmuir、Freundlich 和 Dubinin Radushkevich（D-R）模型应用于平衡数据，结果表明，在 pH 值为 5.5、接触时间为 120 分钟、温度为 25°C 的条件下，生物吸附的最大容量和效率最高。对于添加了 20 mg L 的 Hg（II），具有 1、7、14、21 和 28 天孵育时间的生物膜样品的吸附值分别为 101.31（55.72%）、24.41（67.12%）、16.81（61.37%）、9.70（62.57%）和 13.34（65.38%）mg g。从 D-R 模型得出的自由平均生物吸附能在所有生物膜发育孵育时间下均在 2.24 到 2.36 kJ mol 之间，这表明 Hg(II)的生物吸附机制为物理吸附。热力学研究表明，生物膜上的 Hg(II)生物吸附在热力学上是可行的，具有自发和放热的性质。动力学参数表明，Hg(II)生物吸附到生物膜上与拟二级动力学模型有很好的相关性。吸附后的 FTIR 光谱表明，胺、羟基和羧基是可用的主要官能团，负责 Hg(II)生物吸附到生物膜上。实验数据表明，无纺聚丙烯和聚乙烯土工织物上生长的生物膜可有效去除受污染城市和工业径流中的汞离子。
