Elewa Amal M, Amer Ahmed A, Attallah Mohamed F, Gad Hamdy A, Al-Ahmed Zehbah Ali Mohamed, Ahmed Inas A
Department of Chemistry, Faculty of Science, Zagazig University, Zagazig 44519, Egypt.
Analytical Chemistry and Control Department, Hot Laboratories and Waste Management Center, Atomic Energy Authority of Egypt, Cairo 13759, Egypt.
Materials (Basel). 2023 Feb 1;16(3):1251. doi: 10.3390/ma16031251.
Rice husk was converted into activated carbon (AC) as a byproduct of agricultural waste in an electric furnace at 700 °C and chemically activated using three distinct processes: NaOH AC(C), acetic acid AC(C-1), phosphoric acid AC(C-2), and carbonization AC(C-3) without any chemical activation. To characterize the activated carbon and the removal efficiencies of Fe(III) and Mn(II) from aqueous solutions, various analytical tools were used. The results revealed that the capacities of the four adsorbents to adsorb Fe(III) or Mn(II) from an aqueous solution differ significantly. AC(C-3) was chosen for additional research. The impact of different operational factors, including pH, contact time, adsorbent dosage, starting metal ion concentration, interfering ions, and temperature, were investigated. The optimum pH values for Fe(III) and Mn(II) adsorption were found to be pH 3 and pH 6, respectively. The results obtained were utilized to assess the kinetics and thermodynamics of the adsorption process. The sorption of Fe(III) and Mn(II) ions was found to be a pseudo-second-order kinetic process, and the equilibrium data were fitted with the Langmuir isotherm. Additionally, the evidence suggests that an endothermic mechanism governs the adsorption process. The maximum adsorption capacities of Fe(III) and Mn(II) were 28.9 and 73.47 mg/g, respectively.
稻壳在700℃的电炉中被转化为活性炭（AC），作为农业废弃物的副产品，并通过三种不同的化学活化方法进行处理：氢氧化钠活化活性炭（AC(C)）、乙酸活化活性炭（AC(C-1)）、磷酸活化活性炭（AC(C-2)）以及未经过任何化学活化的碳化活性炭（AC(C-3)）。为了表征活性炭以及其从水溶液中去除铁（III）和锰（II）的效率，使用了各种分析工具。结果表明，四种吸附剂从水溶液中吸附铁（III）或锰（II）的能力存在显著差异。选择AC(C-3)进行进一步研究。研究了包括pH值、接触时间、吸附剂用量、初始金属离子浓度、干扰离子和温度等不同操作因素的影响。发现吸附铁（III）和锰（II）的最佳pH值分别为pH 3和pH 6。所得结果用于评估吸附过程的动力学和热力学。发现铁（III）和锰（II）离子的吸附是一个准二级动力学过程，平衡数据符合朗缪尔等温线。此外，有证据表明吸附过程受吸热机制控制。铁（III）和锰（II）的最大吸附容量分别为28.9和73.47 mg/g。
