Simultaneous Removal of Hg(II) and Phenol Using Functionalized Activated Carbon Derived from Areca Nut Waste

Abstract

Areca nut waste was utilized to obtain high surface area activated carbon (AC), and it was further functionalized with succinic anhydride under microwave irradiation. The surface morphology and surface functional groups of the materials were discussed with the help of scanning electron microscope(SEM) images and fourier transform infra-red (FT-IR) analysis. The specific surface area of the AC and functionalized-AC was obtained by the Brunauer-Emmett-Teller (BET) method, and found to be 367.303 and 308.032 m 2 /g, respectively. Batch experiments showed that higher pH favoured the removal of Hg(II), whereas the phenol removal was slightly affected by the changes in the solution pH. The kinetic data followed pseudo-first order kinetic model, and intra-particle diffusion played a significant role in the removal of both pollutants. The maximum sorption capacity of Hg(II) and phenol were evaluated using Langmuir adsorption isotherms, and found to be 11.23 and 5.37 mg/g, respectively. The removal of Hg(II) was significantly suppressed in the presence of chloride ions due to the formation of a HgCl 2 species. The phenol was specifically adsorbed, forming the donor-acceptor complexes or π-π electron interactions at the surface of the solid. Further, a fixed-bed column study was conducted for both Hg(II) and phenol. The loading capacity of the column was estimated using the nonlinear Thomas equation, and found to be 2.49 and 2.70 mg/g, respectively. Therefore, the study showed that functionalized AC obtained from areca nut waste could be employed as a sustainable adsorbent for the simultaneous removal of Hg(II) and phenol from polluted water.

Enhancement of heavy metal ion adsorption using electrospun polyacrylonitrile nanofibers loaded with ZnO nanoparticles

“…[39][40][41] Increasing the pH of the solution leads to an increase in the negatively charged surface sites due to de-protonation which facilitate the adsorption of the heavy metal cations. 41,42 This was observed in Figure 6 at around pH 5-7 for the adsorption of Pb(II) and Cd(II). The slight decrease in the percent removal of metal ions at higher pH values (pH > 7) could be related to the possible formation of insoluble metal hydroxide precipitates in the solution.…”

“…43 It is worth mentioning that the point of zero charge of the pH (pH pzc ) could be measured to precisely determine the condition of no net charge on the surface of the adsorbent. 42,44 The surface of the adsorbent solids carries a net positive charge if the pH value lies below the pH pzc , and a net negative charge for pH beyond the pH pzc . In this work, the pH values that give the maximum adsorption performance were applied in all subsequent adsorption experiments.…”

Zeolites in Phenol Removal in the Presence of Cu(II) Ions—Comparison of Sorption Properties after Chitosan Modification

“…Adsorption capacity of phenol in the dual system was in the range of 0.1-2 mg/g depending on the adsorbent type, whereas Zn(II) ions sorption remained on the level of 4 mg/g. Lalhmunsiama et al [57] studied the removal of phenol in the presence of Hg(II) on functionalized activated carbon derived from areca nut waste with the result of sorption capacity for phenol in the range of 3.27-4 mg/g. Figure 6 shows that adsorption capacity of NaP1 and NaP1CS in dual component system reached about 1.25 mg/g for the initial concentration of 100 mg/L, and it was significantly higher than the adsorption capacity of NaP1 in the same experimental conditions.…”

One Step Hydrothermal Synthesis of Magnesium Silicate Impregnated Palm Shell Waste Activated Carbon for Copper Ion Removal

“…To analyze the kinetic adsorption process, the pseudo-first and pseudo-second order kinetics models were used. The pseudo first-order kinetic model is expressed as follows [25]:…”

“…A great deal of research has investigated micropollutant removal using modified activated carbon with amine groups [15,16], Fe 2 O 3 impregnation [17,18], anionic surfactants [19,20] and others. However, commercial active carbon is expensive, thus, several studies have been conducted to find economical adsorbents such as bamboo [21,22], spent tea leaves [23], nut shell [24,25], sawdust [26], and cotton hull [27]. In this study, palm shell waste activated carbon (PPAC) was used, which is a cost-effective material [28].The effectiveness of magnesium silicate (MgSiO 3 ) for PTMs removal was recently studied [29], and it was noted that MgSiO 3 has the capability for ion exchange between Mg(II) and positively charged metal ions.…”