Simultaneous removal of multiple heavy metals from wastewater by novel plateau laterite ceramic in batch and fixed-bed studies. Issue 5 (October 2021)

• Record Type: Journal Article
• Authors: Zhu, Dirui; He, Yi; Zhang, Boaiqi; Zhang, Nan; Lei, Zhongfang; Zhang, Zhenya; Chen, Guiyun; Shimizu, Kazuya
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 5(2021)
• Publication Date: 2021-10
• Subjects: PLC plateau laterite ceramic; Adsorption -- Heavy metals -- Plateau laterite ceramic -- Fixed-bed study; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105792
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The wastewater in mining is usually contaminated by multi-heavy metals, and the removal of heavy metals in aqueous solutions by adsorption is a hot topic nowadays. Low-cost, multi-target, sufficient capability, and good reusability are always the first considerations for adsorbents. In this study, a unique plateau laterite ceramic (PLC) made from a characteristic clay soil that naturally contained rich Fe and Al ions was used to simultaneously adsorb six heavy metals from wastewater in batch and fixed-bed experiments. The adsorption isotherms, kinetics, and pH effects were investigated thoroughly. The Langmuir model, pseudo-first-order, and pseudo-second-order kinetic models fitted the experimental data, indicating that the adsorption process was monolayer adsorption, and both physisorption and chemisorption occurred. The pH of the zero-point charge (pHzpc ) of the prepared PLC was 6.8, and the best adsorption efficiencies were 97.38% (As), 96.55% (Cr), 95.62% (Pb), 89.85% (Cu), 87.14% (Cd), and 81.08% (Hg). The crystalline morphology observed by scanning electron microscopy (SEM) along with new and enhanced X-ray diffraction (XRD) peaks revealed that heavy metals were successfully adsorbed onto the PLC. In the fixed-bed study, breakthrough occurred at 270 bed volume (12.72 L). The regeneration ability of the PLC could meet at least three cycles. The adsorption capacity was ranked as As > Cr > Pb > Cu > Cd > Hg in both the batch and fixed-bed experiments. The removal efficiency of As was the best because, except for the dominant complexation and precipitation reaction, As ions had a wider reaction pH range, underwent ligand exchange, and were involved in the formation of an As–Fe shell. Hence, plateau laterite was used for the first time in this study as a ceramic adsorbent to simultaneously adsorb six heavy metals from wastewater. The PLC exhibited a solid structure and easy separation qualities in all experiments, thus having significant implications for removing multiple heavy metals from wastewater in practice. Graphical Abstract: ga1 Highlights: Plateau laterite ceramic (PLC) is an efficient and relatively low-cost adsorbent. PLC exhibits high selectivity for As due to wide reaction pH and multiple reaction ways. PLC provides abundant Fe and Al, thereby avoids artificial addition. The solid-structured PLC is easy to separate and dispose of after use. PLC performed well on the removal of six heavy metals from wastewater simultaneously.