Ahmed Sobur, Shahriar Abrar, Rahman Nazia, Alam Md Zahangir, Nurnabi Mohammad
Institute of Leather Engineering and Technology, University of Dhaka, 44-50, Hazaribagh, Dhaka, 1209, Bangladesh.
Institute of Nuclear Science and Technology, Bangladesh Atomic Energy Commission, Dhaka, 3787, Bangladesh.
J Hazard Mater Adv. 2024 May;14:None. doi: 10.1016/j.hazadv.2024.100427.
Water pollution caused by chromium released from tannery is a serious concern to the environment and public health. Chromium removal from tannery effluent is a crying need before discharging to the surface water. In this study, acrylic acid-grafted sawdust was prepared by Tectona grandis sawdust grafting with acrylic acid employing gamma irradiation in the presence of air and Mohr's salt. It was treated with NaOH and the characterization of surface morphology and functional groups of modified sawdust was studied by SEM and FTIR.. The effects of solution pH, adsorbent dosage, adsorption time, and initial Cr(III) ion concentration were investigated by batch sorption studies. The process was found to be pH, temperature and concentration dependent. Langmuir and Freundlich isotherms were applied to realize the adsorption process in depth, and it was found that the Langmuir isotherm model fitted well with experimental data (R value of 0.983). The maximum monolayer adsorption capacity of acrylic acid-grafted sawdust for Cr(III) from aquous solution was found to be 21.55 mg g at 25 °C. Pseudo-first-order and pseudo-second-order kinetic models were employed to analyze the kinetics of the process, and it was found that the experimental process followed the pseudo-second-order kinetic model, i.e. chemisorption. This study revealed that acrylic acid-grafted sawdust has a decent potential for the removal of Cr(III) from tannery effluents.
制革厂排放的铬所造成的水污染对环境和公众健康构成严重威胁。在将制革厂废水排放到地表水之前，去除其中的铬是当务之急。在本研究中，通过在空气和莫尔盐存在的情况下利用γ射线辐照，使柚木锯末与丙烯酸接枝制备了丙烯酸接枝锯末。用氢氧化钠对其进行处理，并通过扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）研究了改性锯末的表面形态和官能团特征。通过分批吸附研究考察了溶液pH值、吸附剂用量、吸附时间和初始Cr(III)离子浓度的影响。发现该过程取决于pH值、温度和浓度。应用朗缪尔等温线和弗伦德利希等温线深入了解吸附过程，发现朗缪尔等温线模型与实验数据拟合良好（R值为0.983）。在25℃下，丙烯酸接枝锯末对水溶液中Cr(III)的最大单层吸附容量为21.55 mg/g。采用准一级动力学模型和准二级动力学模型分析该过程的动力学，发现实验过程遵循准二级动力学模型，即化学吸附。本研究表明，丙烯酸接枝锯末在去除制革厂废水中的Cr(III)方面具有良好的潜力。
