# Activated Carbons as Effective Adsorbents of Non-Steroidal Anti-Inflammatory Drugs
## 4 Discussion  
The adsorption of sodium salts of non-steroidal anti-inflammatory drugs, naproxen sodium, diclofenac sodium, and ibuprofen sodium, on GAC activated carbon is presented in the manuscript. As part of a comprehensive analysis of the process of removing pharmaceuticals from aqueous solutions, studies of the equilibrium and kinetics of adsorption at various temperatures were performed. The applied adsorption rate testing methodology made it possible to conduct research under strictly controlled conditions of temperature and mixing speed to obtain high-quality kinetic data. Each kinetic curve contained at least 70 experimental points. The use of numerous models and equations of adsorption kinetics and equilibrium to analyze data on the size and rate of sorption, as well as the estimation of thermodynamic parameters, allowed for a precise determination of the mechanism and nature of adsorption of NPX, IBP, and D on GAC activated carbon. Additionally, the study presents changes in the value of zeta potential and thermal stability of GAC due to the adsorption of selected pharmaceuticals. The literature on the subject contains many studies on similar subjects, but there is a clear lack of accurate and detailed equilibrium data and, in particular, adsorption kinetics.  
[PERSON] et al. (2018) analyzed the adsorption of ibuprofen sodium and diclofenac sodium on activated carbons synthesized from murumuru waste. The adsorption isotherms were obtained at temperatures of 28, 35, and 45 \({}^{\circ}\)C. The kinetic curves were also obtained at ambient temperature, in a narrow time range, consisting of several experimental points. [PERSON] and colleagues (2018) studied the adsorption of ibuprofen, ketoprofen, naproxen, and diclofenac on activated carbon obtained from olive waste. The equilibrium and adsorption kinetics studies were carried out at 25 \({}^{\circ}\)C. Moreover, sorption rate data were recorded for approximately 26 h and included several experimental points. [PERSON] et al. (2019) studied the adsorption of ibuprofen on activated carbon (Radix Angelica Dahuricareside) over a wide temperature range at 20, 30, 40, 50, and 60 \({}^{\circ}\)C. [PERSON] and colleagues (2018) studied the adsorption of paracetamol, ibuprofen, and naproxen on ordered mesoporous carbons at 25 \({}^{\circ}\)C. [PERSON] and [PERSON] studied the adsorption of naproxen sodium (2018) and diclofenac sodium (2018) on commercially available activated carbons ROW 08 Supra, F-300, and WG-12. Isotherms at 20, 30, and 40 \({}^{\circ}\)C and kinetic curves (including several experimental points) at 20 \({}^{\circ}\)C were obtained. [PERSON] (2018) studied the equilibrium and kinetics of ibuprofen adsorption on green activated carbon at 25 \({}^{\circ}\)C. In the future, the adsorption process of other drugs from aqueous solutions should be optimized, for example, antibiotics, heart medications, and other non-steroidal anti-inflammatory drugs. Moreover, it is necessary to look for other adsorbents obtained from waste raw materials, which is in agreement with the principles of sustainable development and green chemistry.