The adsorption studies of phenol derivatives on halloysite-carbon adsorbents by inverse liquid chromatography

Abstract

The adsorption of chloroxylenol and chlorophene on halloysite-carbon composites was investigated in batch and flow systems. The synthesis of halloysite-carbon composites through two different methods was performed with microcrystalline cellulose as carbon precursor. The obtained halloysite-carbon composites were characterized by SEM/EDS analysis, the low-temperature nitrogen adsorption/desorption methods, and infrared spectrometry (FT-IR). The SEM/EDS analysis and FT-IR spectra confirmed the presence of carbon on the surface of the halloysite. On the basis of the measurement results in the batch system, the two composites with the best adsorption properties for both adsorbates were chosen for measuring the flow system (using the inverse liquid chromatography). Removal efficiency was equal to 92.26 and 81.36%. It was obtained for chloroxylenol on HNT-m 800 and HNT-Zn 500, respectively. For chlorophene, the removal efficiency had the value of 78.79 and 77.87% on HNT-m 800 and HNT-Zn 800, respectively. Adsorption parameters of chloroxylenol and chlorophene were determined with inverse liquid chromatography methods: the adsorption equilibrium constants were determined with the peak division method and the adsorption capacity of the adsorbents was determined with the breakthrough curve method. Maximum adsorption capacity for the adsorption of chloroxylenol on HNT-m 800 was 5.48 mg·g−1 and on HNT-Zn 500 its value was 2.77 mg·g−1. For the adsorption of chlorophene on HNT-m 800 the value was 4.44 mg·g−1 and on HNT-Zn 800–2.5 mg·g−1. Halloysite-carbon composites can be successfully used as effective adsorbents for removing chloroxylenol and chlorophene from solutions in the flow system.