Removal of dieldrin from aqueous solution by a novel triolein-embedded composite adsorbent

Abstract

In this study, a novel triolein-embedded activated carbon composite adsorbent (CA-T) was prepared and applied for the adsorption and removal of dieldrin from aqueous systems. Experiments were carried out to investigate the adsorption behavior of dieldrin on CA-T, including adsorption isotherms, adsorption kinetics, the influence of initial concentration, temperature, shaking speed, pH and the addition of humic acid (HA) on adsorption. The adsorption isotherms accorded with Freundlich equation. Three kinetics models, including pseudo-first-order, pseudo-secondorder and intraparticle diffusion models, were used to fit the experimental data. By comparing the correlation coefficients, it was found that both pseudo-second-order and intraparticle diffusion models were used to well describe the adsorption of dieldrin on CA-T. The addition of HA had little effect on dieldrin adsorption by CA-T. Results indicated that CA-T appeared to be a promising adsorbent for removing lipophilic dieldrin in trace amount, which was advantageous over pure granular activated carbon (GAC). The adsorption rate increased with increasing shaking speed, initial concentration and temperature, and remained almost unchanged in the pH range of 4-8. Thermodynamic calculations indicated that the adsorption reaction was spontaneous with a high affinity and the adsorption was an endothermic reaction.

Preparation and characterization of a novel silica aerogel as adsorbent for toxic organic compounds

“…The K f and n of Aerogel B on RhB were 1.16 and 0.73, respectively. On the other hand, Aerogel A exhibited a very strong adsorption capacity on dieldrin, the K f was 30.22, 11 times greater than that of active carbon, and 10 times greater than that of cellulose acetate [22]. Besides the high porosity and lipophilic surface, low density also played an important role for the high adsorption capacity exhibited by Aerogel A.…”

Research progress of novel adsorption processes in water purification: A review

“…Semi-permeable membrane devices (SPMD), which are based on the diffusion of hydrophobic substances from water to membrane bags filled with lipophilic phases, are widely used for monitoring organic contaminants in water (Huckins et al, 1990;Lu et al, 2002;Lu and Wang, 2003;Frank, 2005). Recently, a novel composite absorbent, triolein-embedded sorbent, is proposed for selectively removing trace POPs from water (Ru et al, 2007a(Ru et al, , 2007bHuo et al, 2005aHuo et al, , 2005bLiu et al, , 2007.…”

“…Three sorbents were produced which were composed of supporting activated carbon (Ru et al, 2007a(Ru et al, , 2007b or silicon gel granules (Huo et al, 2005a(Huo et al, , 2005b) and the surrounding triolein-embedded cellulose acetate membrane, or CA-triolein sphere (Liu et al, , 2007, respectively. The analysis results of SEM and XPS for the sorbent showed that the triolein was wrapped in the thin CA polymer and constituted a significant fraction of the lipid pool in the sorbent.…”

Biomimetic Adsorbents: Enrichment of Trace Amounts of Organic Contaminants (TAOCs) in Aqueous Solution

“…According to the principle of similarity and intermiscibility, triolein has a strong absorbability for trace level of hydrophobic organic pollutants. Previous studies Liu et al, 2009;Huo et al, 2005;Ru et al, 2007;Qu, 2008) showed the preparation of a biomimetic adsorbent by embedding triolein into cellulose acetate (CA) spheres. The section structure is shown in Fig.…”