Department of Chemistry, University of Engineering and Technology, Lahore, 54890, Pakistan.
Department of Chemistry, University of Engineering and Technology, Lahore, 54890, Pakistan.
J Environ Manage. 2018 Oct 1;223:771-778. doi: 10.1016/j.jenvman.2018.06.080. Epub 2018 Jul 4.
Nitrobenzene (NB) is a kind of persistent organic pollutant. A ubiquitous and cost-effective substance spent black tea (SBT) was investigated for the removal of nitrobenzene from aqueous media. The maximum uptake potential of dried biomass (SBT) for NB was found to be 14.86 mg per gram (q) in a batch experimental set-up. Equilibration time for NB sorption was about 50 min, and optimal removal efficiency was achieved at a dosage of 2 g/L with an initial concentration of 100 mg/L of NB. Findings revealed that NB uptake increased with an increase in the temperature from 273 K to 353 K. Sorption was also found to be pH sensitive, sorption improved as the pH value changes from alkaline to acidic (from 10 to 2). Different isotherm (Langmuir, Freundlich, Temkin and Dubinin Radushkevich) and kinetic models (pseudo-1st order, pseudo-2nd order and Elovich models) were applied to experimental results; the sorption mechanism was well described by the Freundlich and pseudo-2nd order models. Moreover, Scanning electron micrographs, ATR-FTIR spectra and the results of elemental analysis also supported the efficacy of SBT as an efficient bio-sorbent for the elimination of NB from water.
硝基苯（NB）是一种持久性有机污染物。本研究选用一种普遍存在且经济有效的物质——黑茶 spent black tea（SBT），用于去除水溶液中的硝基苯。在分批实验装置中，发现干燥生物质（SBT）对 NB 的最大吸附量为 14.86mg/g（q）。NB 吸附的平衡时间约为 50min，在初始 NB 浓度为 100mg/L 时，投加量为 2g/L 时，去除效率最佳。研究结果表明，NB 的吸附量随温度从 273K 升高到 353K 而增加。吸附还表现出对 pH 值的敏感性，随着 pH 值从碱性变为酸性（从 10 变为 2），吸附效果得到改善。应用了不同的等温线（朗缪尔、弗伦德利希、特姆金和杜宾-拉什科夫斯基）和动力学模型（拟一级、拟二级和艾洛维奇模型）来处理实验结果；吸附机制很好地用弗伦德利希和拟二级模型描述。此外，扫描电子显微镜照片、ATR-FTIR 光谱和元素分析结果也支持 SBT 作为一种有效的生物吸附剂，可有效去除水中的 NB。
