The influence of chlorinated aromatics’ structure on their adsorption characteristics on activated carbon to tackle chemical spills in drinking water source

Abstract

This study focused on evaluating the efficiency of powdered activated carbon (PAC) adsorption process and tackling chlorobenzenes and chlorophenols spill in drinking water source. The adsorption kinetics and PAC's capacities for five chlorobenzenes and three chlorophenols at drinking water contamination levels were studied in order to determine the influence of different functional groups on the adsorption behavior. The results showed that PAC adsorption could be used as an effective emergency drinking water treatment process to remove these compounds. The adsorption kinetics took 30 min to achieve nearly equilibrium and could be described by both pseudo first-order and pseudo second-order models. A mathematic relationship was developed between the pseudo first-order adsorption rate constant, k 1 , and the solutes' properties including lgK ow , polarizability and molecular weight. The Freundlich isotherm equation could well describe the adsorption equilibrium behaviors of chlorinated aromatics with r 2 from 0.920 to 0.999. The H-bond donor/acceptor group, hydrophobicity, solubility and molecular volume were identified as important solute properties that affect the PAC adsorption capacity. These results could assist water professionals in removing chlorinated aromatics during emergency drinking water treatment.

Understanding Electrocatalytic Hydrodechlorination of Chlorophenols on Palladium-Modified Cathode in Aqueous Solution

“…The lower pH led to the improvement of 2,4-DCP adsorption to some extent, indicating that the acidic conditions can promote the adsorption of 2,4-DCP on the electrode. This result was consistent with the literature, , which reported that the adsorption of CPs on activated carbon increased with the decrease in pH. According to the literature, the solubility of 2,4-DCP decreases with the decrease in pH.…”

Sweep-Out of Tigecycline, Chlortetracycline, Oxytetracycline, and Doxycycline from Water by Carbon Nanoparticles Derived from Tissue Waste

“…The multi-carbonyl groups of these drugs would be protonated in acidic media (pH < 6.0), and the cationic-formed sites may repel each other and prevent multilayer sorption. In contrast, in an alkaline media of (pH > 8), the hydroxyl groups may compete with the drugs on the sorbent sites, and the deprotonate hydroxyl groups of a drug may increase the repulsion [ 75 , 76 ].…”

Behavior of graphitized carbon blacks in the electrodegradation and sorption of chlorophenoxyacetic acids

“…According to literature data, the adsorption capacity of chlorine-containing organics generally depends on the number of chlorine atoms in sorbate molecules [12], but with respect to particular chlorophenoxyacetic acids, it depends on the porous structure, surface area, electronic properties and surface chemistry of the carbon materials [13]. The diverse surface structures of the carbon blacks tested explain the differences in the uptake of the chloroorganics (A 4-CPA , A 2.4-D ) during their adsorption (Table 1).…”