Removal of an emerging pharmaceutical pollutant (metronidazole) using PPY-PANi copolymer: Kinetics, equilibrium and DFT identification of adsorption mechanism

Linear and nonlinear investigations for the adsorption of paracetamol and metformin from water on acid-treated clay

“…Also, the adsorption appeared to go less spontaneous as the temperature increased. Nevertheless, the obtained ΔG o values (less than 20 kJ mol −1 ) indicated that the adsorption process is a physisorption 67 , 68 , 83 , 86 – 88 .

Figure 6 The plot of ln K c against 1/ T for the adsorption of different initial feed concentrations of ( a ) MF on WTC, ( b ) MF on ATC, ( c ) MF on WTC, and ( d ) MF on ATC.

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“…The negative ΔH o values indicated the exothermic nature of the adsorption of PA and MF on both sorbents meaning that the adsorption efficiency may be enhanced by lowering the solution’s temperature. Besides, a ΔH o of less than 40 kJ mol indicates a physisorption process; conversely, it is considered chemisorption when having a ΔH o of 80–450 kJ/mol 81 – 83 . The adsorption spontaneity was inferred from the negative ΔG o values for both pollutants on WTA and ATC 84 ; this finding was supported by the negative ΔS o values 85 .…”

Removal of two cytostatic drugs: bleomycin and vincristine by white-rot fungi – a sorption study

“…Thus, the change in Gibbs free energy (∆G°), enthalpy (∆H°) and entropy (∆S°) were determined for three different temperatures (15.4, 22.5, 29.6 °C) at pH 6 and the results are presented in Table 5 . The positive value of ∆H° (37,630 kJ/mol) for bleomycin confirmed the endothermic nature of removal process of these drug and its chemisorption type [ 7 ], while a negative change in enthalpy for vincristine (∆H° = −233,865 kJ/mol) revealed the exothermic nature of the process for this pharmaceutical and confirmed its physisorption type [ 1 , 15 ]. The positive value of ∆S° for bleomycin indicated an increase of entropy as a result of adsorption.…”

Synthesis and characterization of arginine-doped heliotrope leaves with high clean-up capacity for crystal violet dye from aqueous media

“…The advancement of a viable economic method of waste management for the coloring industry has long been essential for protecting the environment. In order to clean wastewater and eliminate dyes, numerous treatment approaches have been employed, like photodegradation (Ait Ahsaine et al 2018;Naciri et al 2018Naciri et al , 2019aNaciri et al , 2019bNaciri et al , 2020aNaciri et al , 2020bNaciri et al , 2021Chennah et al 2019;Erdogan et al 2019;Shaim et al 2019;Barebita et al 2020;Bouziani et al 2020Bouziani et al , 2021Akhsassi et al 2021;Mimouni et al 2021), biological oxidation (Paz et al 2017;Sathishkumar et al 2019), nanofiltration membranes (Saffaj et al 2005), ozonation (Oguz et al 2005;Gharbani et al 2008), and adsorption (Kizito et al 2017a(Kizito et al , 2017bAjmal et al 2018Ajmal et al , 2020aAjmal et al , 2020bAarab et al 2020aAarab et al , 2020bBa Mohammed et al 2020). The latter is enhanced compared to other wastewater treatment methods in terms of its preliminary expense, flexibility, easiness of layout, ease of function, and insensitivity toward toxic pollutants (Benafqir et al 2019;Hsini et al 2020aHsini et al , 2021aHsini et al , 2021b.…”