Removal of phenolphthalein and methyl orange from laboratory wastewater using tetraethylammonium modified kaolinite clay
Adewale Adewuyi, Rotimi A. Oderinde
Abstract
Developing an efficient technique for the treatment of laboratory wastewater is a challenge. In response, kaolinite clay (CLY) was functionalized with tetraethylammonium bromide to produce tetraethylammonium modified kaolinite clay ([email protected]). Both CLY and [email protected] were characterized with X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM). CLY and [email protected] were evaluated for their ability to remove phenolphthalein (PH) and methyl orange (MO) from laboratory wastewater. Peaks from FTIR and XRD suggests the formation of [email protected], while SEM micrograph revealed the surfaces of CLY and [email protected] to be irregularly shaped while [email protected] has some patches. The adsorption capacities exhibited by [email protected] towards PH (43.00 mg g−1) and MO (40.00 mg g−1) were found more promising compared to CLY, which showed 20.00 and 22.00 mg g−1 towards MO and PH, respectively. The ΔHo value for the sorption of PH was found to be −71.7523 kJ mol−1, while the value was −46.1826 kJ mol−1 for MO. The ΔHo values are negative in nature which suggests the process to be exothermic. The removal of MO and PH from the solution may be described by Langmuir isotherm with a regeneration capacity above 80% even at the 14th regeneration cycle. Applying [email protected] towards the purification of raw laboratory wastewater contaminated with PH and MO further proves the effectiveness of [email protected] as a potentially efficient material for the purification of laboratory wastewater systems contaminated with PH and MO.