RESUMO
A cellulose-g-poly-(acrylamide-co-sulfonic acid) polymeric bio-adsorbent (CASA) was prepared by grafting copolymerization, and used to adsorb Cr(III) from leather wastewater. The SEM, XRD, FTIR, and XPS results showed that CASA contains many spherical particles and functional groups such as NH2, CO, and HSO3. The adsorption experiments revealed that CASA presented excellent adsorption performance for Cr(III) (274.69 mg/g of max adsorption capacity) from high-salinity wastewater, which was much better than other reported adsorbents with different structures. Meanwhile, adsorption equilibrium could be reached within 10 min due to the introduction of abundant sulfonic acid groups on its surface. In addition, the adsorption process followed the Langmuir adsorption isotherm, and the experimental data conformed to the pseudo-second-order kinetics model. Moreover, the main adsorption mechanisms include chelation, electrostatic interactions, and cation exchange, which provide an important theoretical basis for the removal of toxic inorganic pollutants from leather wastewater.
Assuntos
Acrilamida/química , Celulose/química , Cromo/isolamento & purificação , Ácidos Sulfônicos/química , Águas Residuárias/química , Purificação da Água/métodos , Adsorção , Cátions , Cromo/química , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletroquímica de Varredura/métodos , Poli G/química , Polímeros/química , Salinidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Eletricidade Estática , Água/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
In this study, the sulfonic group was introduced to prepare high-performance Eucommia ulmoides lignin-based biochar, which was used to remove tetracycline hydrochloride. The BET area (2008 m2 g-1) of sulfonated biochar was twice that of unmodified biochar. Through XRD and Raman analysis, the synergetic pyrolysis mechanism of the sulfonic group in the formation of the porous structure was discussed. Sulfonated biochar had excellent adsorption performance for tetracycline hydrochloride (Qm: 1163 mg g-1), while the adsorption performance of unmodified biochar was about only one-fourth (Qm: 277.7 mg g-1) of that. The adsorption of tetracycline hydrochloride by the sulfonated biochar was spontaneously endothermic and conformed to the Langmuir isotherm model. The adsorption process was confirmed by pseudo-second-order kinetic model. Moreover, the sulfonic group on the sulfonated biochar significantly promoted the formation of the hydrogen bond and greatly improved the adsorption performance.