Saw-sedge Cladium mariscus as a functional low-cost adsorbent for effective removal of 2,4-dichlorophenoxyacetic acid from aqueous systems

Abstract

For the first time in the published literature, a study is described concerning the use of the saw-sedge Cladium mariscus (C. mariscus) for adsorption of 2,4dichlorophenoxyacetic acid (2,4-D) from aqueous systems. Among the experiments carried out, the elemental composition of C. mariscus was determined (C = 48.0 %, H = 7.1 %, N = 0.95 %, S = 0.4 %), FTIR spectroscopic analysis was performed to confirm the chemical structure of the adsorbent, and porous structure parameters were measured: BET surface area (A BET = 0.6 m 2 /g), total pore volume (V p = 0.001 cm 3 /g) and average pore size (S p = 6.6 nm). It was shown that the effectiveness of removal of 2,4-D from aqueous systems using C. mariscus depends on parameters of the process: contact time, system pH, mass of sorbent, and temperature. Maximum adsorption was attained for a solution at pH = 3. Further increase in the alkalinity of the tested systems led to a reduction in the effectiveness of the process. The kinetic of adsorption of 2,4-D by C. mariscus was also determined, and thermodynamic aspects were investigated. The experimental data obtained correspond to a pseudo-second-order kinetic model of type 1. Additionally the negative values obtained for DH8 indicate that the process is exothermic, and the negative values of DG8 show it to be spontaneous. As the temperature of the system increases the spontaneity of adsorption is reduced, in accordance with the exothermic nature of the process.

Removal of 2,4-D herbicide from aqueous solution by aminosilane-grafted mesoporous carbons

“…A comparison of literature sorption capacities of different materials towards 2,4-D herbicide is presented in Table 4. Aminosilane-grafted mesoporous carbons are more effective adsorbents of 2,4-D than powdered activated carbons (Aksu and Kabasakal 2004), Cladium mariscus (Bartczak et al 2016), chitosan (Harmoudi et al 2014), chitin (Harmoudi et al 2014), blast furnace sludge (Gupta et al 2006), blast furnace dust (Gupta et al 2006) or modified silica gel (Koner et al 2013). This high adsorption capacity could be ascribed to the unique properties of carbon materials obtained (Goscianska and Olejnik 2018).…”

“…It was found that removal of 2,4-D by carbon adsorbents at the initial stage increased with an increase in pH from 2 to 3, then remained almost unaffected up to pH of 5. Further increase of pH in the range from 7 to 11 led to a decrease in sorption capacity of materials towards 2,4-D. Because of low pKa value (2.73) of herbicide, it exists predominantly in anionic form (Bartczak et al 2016;Koner et al 2013). In acidic solutions the aminosilane-grafted mesoporous carbons become more positively charged which results in greater adsorption of anionic species.…”

“…where R is the universal gas constant (8.314 (J/K mol)), T is the absolute temperature (K), and K C is the adsorption constant (Bartczak et al 2016;Koner et al 2013;Gupta et al 2016).…”

“…Large amounts of synthetic organic pollutants including pesticides, herbicides, dyes and pharmaceuticals are daily released into many types of wastewaters and enter into natural water channels to be accumulated in the aquatic environment (Agarwal et al 2016; Bartczak et al 2016;Goscianska et al 2017). These contaminations arise from urban, industrial and agricultural human activities.…”

“…2,4-D is commonly applied in agriculture due to its low cost and good selectivity (Liu et al 2016). It stimulates the cells to uncontrolled growth that leads to the plant's death in the last stage (Bartczak et al 2016). 2,4-dichlorophenoxyacetic acid is widely applied in the cultivation of soya, maize, sugar cane and wheat.…”