Study on the Pyrolysis and Adsorption Behavior of Activated Carbon Derived from Waste Polyester Textiles with Different Metal Salts

Abstract

In this study, the effects of the catalysis of heavy metals on the pyrolysis of waste polyester textiles (WPTs) and the adsorption behaviors of the pyrolysis products of WPTs for Cr(VI) were explored. TG−DTG analysis indicated that the metal ions catalyzed the pyrolysis process by reducing the temperature of the decomposition of WPTs. The surface morphology and pore structure of the carbons were analyzed using SEM and BET. The results demonstrated that Zn−AC possessed the largest specific surface area of 847.87 m2/g. The abundant acidic functional groups on the surface of the activated carbons were proved to be involved in the Cr(VI) adsorption process via FTIR analysis. Cr(VI) adsorption experiments indicated that the adsorption process was more favorable at low pH conditions, and the maximum adsorption capacities of Zn−AC, Fe−AC, and Cu−AC for Cr(VI) were 199.07, 136.25, and 84.47 mg/g, respectively. The FTIR and XPS analyses of the carbons after Cr(VI) adsorption, combined with the adsorption kinetics and isotherm simulations, demonstrated that the adsorption mechanism includes pore filling, an electrostatic effect, a reduction reaction, and complexation. This study showed that metal salts catalyze the pyrolysis processes of WPTs, and the activated carbons derived from waste polyester textiles are promising adsorbents for Cr(VI) removal.

I2/TBHP Reagent System: A Modern Paradigm for Organic Transformations**

“…Apart from isoquinolines, this reaction was also carried out with quinoline but the corresponding product quinoline-2,3,4(1H)-trione was not detected, rather the Nbenzylation/amidation product 1-benzylquinolin-2(1H)-one, in around 5 % yield was formed (Scheme 11). [70] In plausible mechanism (Scheme 12) initially, the benzylic sp 3 I 2 /TBHP-prompted one-pot triple functionalization of azaarenes via consecutive regioselective iodination, N-benzylation and amidation using methyl arenes was reported by Reddy et.al. This protocol avoids the use of expensive noble metal catalysts and is applicable for the both quinoline and isoquinoline with moderate to excellent yields.…”