Adsorption and removal of phenoxy acetic herbicides from water by using commercial activated carbons: experimental and computational studies

Abstract

In this study, commercial activated carbons (GAB and CBP) were successfully used for the removal of two phenoxy acetic class-herbicides, 4-chloro-2-methyl phenoxy acetic acid and 2.4-dichlorophenoxy acetic acid (MCPA and 2.4-D) from aqueous solution. The adsorbent materials were characterized, and their equilibrium adsorption capacity was evaluated. The results suggest that the microporous properties of GAB activated carbon enhanced the adsorption capacity, in comparison to CBP carbon. Thus, the increasing in the ionic strength favored the adsorption removal of both pesticides, indicating that electrostatic interactions between the pollutant and the adsorbate surface are governing the adsorption mechanism, but increasing pH values decreased adsorption capacity. Experimental data for equilibrium was analyzed by two models: Langmuir and Freundlich. Finally, computational simulation studies were used to explore both the geometry and energy of the pesticides adsorption.

Removal of 4-chloro-2-methylphenoxyacetic acid from water by MIL-101(Cr) metal-organic framework: kinetics, isotherms and statistical models

“…According to the World Health Organization (WHO), as of 2015, an estimate of 663 million people do not have access to clean water, and by 2050, one in every four persons will consume contaminated water in developing nations [12]. The United States Environmental Protection Agency (USEPA) have listed MCPA as priority pollutant with possible carcinogenic and mutagenic effects [13]. The maximum standard limit for MCPA in drinking water is set by the WHO and USEPA as 0.1 µg l −1 [14].…”

Chiral Photonic Liquid Crystal Films Derived from Cellulose Nanocrystals

“…[54,56] Cellulose can be extracted from lignocellulose by acid hydrolysis, enzymatic hydrolysis, mechanical refining, solvent extraction, and oxidation. [57][58][59][60][61][62][63][64] Nowadays, the advantages of low-cost, non-toxic, good biocompatibility, and biodegradability make cellulose widely used in many fields such as mechanical reinforcement materials, [65][66][67][68][69][70] oil-water separation materials, [70][71][72][73][74][75][76] adsorption materials, [77][78][79] medical slow-release materials, [80][81][82][83] and optoelectronic materials. [84][85][86][87][88][89][90][91][92][93] Thus, cellulose has been recognized as the main raw material for the energy and chemical industry in the future.…”

Use of dirty plastic waste as precursors for activated carbon production—A contribution to the circular economy

“…Already published papers regarding the adsorption of MCPA and 2,4-D onto ACs showed that the adsorption depends on the textural and chemical characteristics of the ACs, in particular the acid-base characteristics (Spaltro et al, 2018), and also on the polarity and molecular size of the adsorbate (Cansado et al, 2019). The ACs produced in this work have a basic character, with a point of zero charge (pHpzc) of 7.8, 8.2 and 9.1, for CDR-KOH-1:1-700, PS-Air-760 and PB-CO 2 -8300 samples, respectively.…”