Structural Stability of Ni/Al Layered Double Hydroxide Supported on Graphite and Biochar Toward Adorption of Congo Red

Abstract

In this research, Ni/Al layered double hydroxide (LDH) was modified by using co-precipitation method to generate Ni/Al-graphite (Ni/Al-GF) and Ni/Al-biochar (Ni/Al-BC). The adsorbents were applied to remove Congo Red from aqueous solution. The obtained samples were characterized by using XRD, FTIR, BET and TG-DTA. The XRD diffraction pattern of Ni/Al LDH, Ni/Al-GF, and Ni/Al-BC presented the formation of composite with decreasing crystallinity. The surface area modified LDHs was higher than the pristine materials, which was obtained 15.106 m2/g, 21.595 m2/g and 438.942 m2/g for Ni/Al-LDH, Ni/Al-GF, Ni/Al-BC respectively. The adsorption of Congo Red on the materials was tested at diferent parameters and the results exhibited that Congo Red adsorption on LDHs were pseudo-first-order (PFO) kinetic, spontaneous, endothermic and followed Langmuir model. The adsorbents removed Congo Red by high performance stability with adsorption capacity was 116.297 mg/g for Ni/Al-GF and 312.500 mg/g for Ni/Al-BC. These adsorption capacity was higher than the pristine LDH (61.728 mg/g). The regeneration process which carried out for five cycles showed that Ni/Al-GF and Ni/Al-BC have stable structures as reuse adsorbents for Congo Red from aqueous solution.

Ni/Cr-[α-SiW12O40] Layered Double Hydroxide as Effective Adsorbent of Iron(II) From Aqueous Solution

“…5-6. models, as shown in Eqs. 3 and 4 as similarly reported by Siregar et al [34]. The isotherm adsorption of iron(II) on LDH was presented in Table 3.…”

Utilization of Rambutan Peel as s Potential Adsorbent for the Adsorption of Malachite Green, Procion Red, and Congo Red Dyes

“…The adsorption isotherm parameter was obtained using the Langmuir and Freundlich equations by processing the data on the eff ect of concentration and adsorption temperature on malachite green, congo red, and procion red dyes using rambutan peel bioadsorbent. Langmuir isotherm model illustrates that the adsorption process occurs in a monolayer, while the Freundlich adsorption isotherm explains that the adsorption process takes place in a multilayer manner (Siregar et al, 2021).…”

Layered Double Hydroxide/Chitosan Composite (Mg-Al/CT) as a Selective Adsorbent in Congo Red Adsorption from Aqueous Solution

“…Table 3 shows that the R 2 value tends to follow the Freundlich equation, which means that the absorption of Congo Red occurs by physisorption (physical absorption). Physical adsorption occurs because of physical forces (Siregar et al, 2021). The physically adsorbed molecules are not strongly bound to the surface of the adsorbent, and usually, a fast reversible process occurs, so they are easy to replace with other molecules.…”

“…The greater the concentration of Congo Red, the smaller the degree of adsorption irregularity. Gibbs free energy data (ΔG) shows a negative value which indicates the adsorption process occurs spontaneously for each adsorbent (Siregar et al, 2021).…”