Synergetic removal of hazardous pollutants from aqueous environment using lignocellulosic biosorbents
Jasmina Sulejmanović, Ajla Gostevčić, Amar Karadža, Adnan Zahirović, Anela Topčagić, Jelena Ostojić, Abdullah A. Al‐Kahtani, Farooq Sher
Abstract
Water pollution with dyes that are non-biodegradable has become a very concerning environmental problem in the world today. Therefore, the aim of this research was an optimisation of adsorption process for the removal of one of the most harmful dyes Eriochrome Black T (EBT). For the first time, native hazelnut shells were used as biosorbents in this regard. The biomaterial was analysed by infrared spectroscopy with Fourier transformation infrared spectra, scanning electron microscopy, electron dispersive spectroscopy, Boehm titrations, physicochemical analysis and by determination of zero charge point and cation exchange capacity. Dye concentrations were established by UV-Vis spectrophotometer and heavy metals concentration by flame atomic absorption spectrometry (FAAS). Characterization techniques of EBT showed successful removal from wastewater due to the obvious changes in morphological and composition structure of the hazelnut shell. The highest capacity of adsorption (5.8 mg/g) and removal efficiency (75.3%) was found at pH 3, sorbent mass 500 mg, 80 mg/L concentration, 90 min and temperature 20 °C. The pseudo-second-order model described the best investigated process and maximum Langmuir’s adsorption capacity was 27.55 mg/g. The interfering effect of seven heavy metals increased removal efficiency to 98% showing a positive impact. Furthermore, the process was found feasible with negative values of Gibbs free energy and exothermic with negative values of enthalpy change (-35.26 kJ/mol). The utilized green and environmentally friendly sorbent under optimized conditions could be used in real textile industries for EBT and heavy metals removal.