在世界许多地区,地表水和地下水中砷和氟化物的高共存对人类健康构成了风险。使用单次和竞争性分批平衡吸附研究,本研究的重点是活性炭对As(V)和F的吸附及其模型。BET,XRD,FESEM,EDS,和FTIR分析用于辨别活性炭的结构特征。剂量的影响,pH值,在单一和同时吸附系统中还研究了接触时间。活性炭对砷和氟的最大吸附量分别为3.58mg/g和2.32mg/g,分别。动力学研究表明,伪二阶动力学模型比伪一阶动力学模型拟合更好,埃洛维奇,和粒子内扩散动力学模型。Langmuir的非线性回归分析,Freundlich,托特,RedlichPeterson,并使用改进的LangmuirFreundlich模型来确定单组分吸收模型参数。此外,使用扩展的朗缪尔(EL)对同时吸附进行了严格建模和比较,扩展LangmuirFreundlich(ELF),改良竞争性朗缪尔(MCL),和JeppuAmruthaManipal多组分(JAMM)等温线模型,并解释了同时吸附系统的竞争机制。Further,通过使用归一化平均百分比误差(NAPE)的统计误差分析来评估模型性能,均方根误差(RMSE),和相关系数(R2)。根据建模结果,单平衡数据与修正的LangmuirFreundlich等温线模型拟合更好,As(V)和F的R2较高,为0.99,NAPE较低,为3.8%和1.28%,比其他模型。对于二元吸附,扩展的LangmuirFreundlich等温线模型表现出极好的拟合,误差最小。所有竞争等温线模型都可以很好地拟合As(V)和F同时吸附系统。此外,这项研究揭示了等温线拟合的细微差别,在恒定氟化物浓度下变化的砷中,ELF>EL>MCL>JAMM,和ELF>JAMM>EL>MCL在恒定砷浓度下变化的氟化物。此外,竞争性研究揭示了对选择性吸附的重要见解,As(V)在活性炭上表现出明显的对F的吸附选择性。实质上,由于(V)对F显示出更明显的拮抗行为,而F在砷的吸附中表现出较低的竞争行为。
The elevated co-occurrence of arsenic and
fluoride in surface and groundwater poses risks to human health in many parts of the world. Using single and competitive batch equilibrium adsorption studies, this research focuses on As(V) and F adsorption by activated carbon and its modeling. BET, XRD, FESEM, EDS, and FTIR analysis were used to discern the structural characteristics of activated carbon. The influence of dosage, pH, and contact time were also investigated in single and simultaneous adsorption systems. The maximum adsorption capacity of activated carbon for arsenic and
fluoride were found to be 3.58 mg/g and 2.32 mg/g, respectively. Kinetics studies indicated that pseudo-second-order kinetic model fit better than pseudo-first-order, Elovich, and intraparticle diffusion kinetic models. The non-linear regression analysis of Langmuir, Freundlich, Toth, Redlich Petersons, and Modified Langmuir Freundlich models was used to determine single-component asorption model parameters. Additionally, the simultaneous adsorption was rigorously modeled and compared using the Extended Langmuir (EL), Extended Langmuir Freundlich (ELF), Modified Competitive Langmuir (MCL), and Jeppu Amrutha Manipal Multicomponent (JAMM) isotherm models, and competitive mechanisms were interpreted for the simultaneous adsorption system. Further, the model performances were evaluated by statistical error analysis using the normalized average percentage error (NAPE), root mean square errors (RMSE), and the correlation coefficient (R2). According to the modeling results, single equilibrium data fitted better with the Modified Langmuir Freundlich isotherm model, with a higher R2 of 0.99 and lower NAPE values of 3.8 % and 1.28 % for As(V) and F, than other models. For the binary adsorption, the Extended Langmuir Freundlich isotherm model demonstrated excellent fit with lowest errors. All the competitive isotherm models fit the As(V) and F simultaneous sorption systems reasonably well. Furthermore, the research unveiled a nuanced hierarchy of isotherm fitting, with ELF > EL > MCL > JAMM in varying arsenic at a constant
fluoride concentration, and ELF > JAMM > EL > MCL in varying
fluoride at a constant arsenic concentrations. In addition, competitive studies divulged crucial insights into selective adsorption, as As(V) exhibits a pronounced adsorption selectivity over F on activated carbon. In essence, As(V) showed a more pronounced antagonistic behavior over F, whereas F exhibited a much lesser competitive behavior in the adsorption of arsenic.