Adsorption of Nonylphenol to Multi-Walled Carbon Nanotubes: Kinetics and Isotherm Study

Abstract

We explored the occurrence and distribution of nonylphenol (NP) in 13 Taiwanese source waters. From all the surveyed waters, NP was detected at a high concentration, which could be attributed to contamination by wastewater discharges. In this study, we applied modified multi-walled carbon nanotubes (MWCNTs) for removing NP from aqueous solution. The impact of a few experimental factors, i.e., pH, contact time, MWCNTs dose, and temperature on the NP removal efficiency of modified MWCNTs was studied. The maximum adsorption capacity of the MWCNTs was observed to be 1040 mg NP/g when the initial NP concentration was 2.5 mg/L, and the solution pH was 4. The adsorption process followed the Elovich kinetics and the Elovich isotherm, indicating it is multilayer adsorption. The thermodynamic analysis demonstrated the NP adsorption by MWCNTs was thermodynamically satisfactory and, for the most part, endothermic as in the case of phenol adsorption. The result of the current study demonstrated the significance of free binding sites and the pore size of MWCNTs in the NP adsorption. This paper will help to better comprehend the adsorption behavior and mechanism of alkyl phenolic compounds onto MWCNTs.

Distribution and Removal of Pharmaceuticals in Liquid and Solid Phases in the Unit Processes of Sewage Treatment Plants

“…In order to improve the removal efficiency for the hardly removable compounds, various adsorbents are being developed and applied. For example, porous materials synthesized with nano-carbon tubes or biochar have been applied to remove trace pharmaceuticals and dues from water [66,67]; the results were very promising, so it was expected that pharmaceutical-free water can be discharged if these adsorption technologies are properly designed and applied to remove residual pharmaceuticals after a biological process in an STP. However, still trace pharmaceuticals could be detected even after an adsorption process is applied after a biological one.…”

Multi-Walled Carbon Nanotubes

“…MWCNTs are also being successfully explored in environmental applications, such as for water quality control and treatment. Two interesting reports [9,10] are included in this Special Issue, both of which are related to the use of MWCNTs as adsorbents of contaminants, namely nonylphenol [9] and organochlorine pesticides [10] from source waters and agricultural irrigation water samples, respectively. The contributing authors [9,10] characterized the main operational parameters and the type of adsorption demonstrating the applicability of MWCNTs for the removal and extraction of contaminants from water samples.…”

Pb(II) removal in water via adsorption onto deep eutectic solvent fabricated activated carbon

“…Application of conventional methods (electrochemical treatment, precipitation, reduction, membrane separation and so on) in the treatment of water with metal ions has some drawbacks (secondary pollution, high cost of operation and low efficiency), and adsorption onto suspended particle has shown to be cost-effective and efficient method (Fiyadh et al 2019;He et al 2019). Different adsorbents, including clay (Yin et al 2018), carbon nanotubes (Dai et al 2018), nano-TiO 2 / cellulose composites (Zhang et al 2016) and activated carbon (Kyzas and Mitropoulos 2018), are well exploited in Pb ions removal in water. Activated carbon, among various adsorbent, is a well-developed porous material with an excellent performance, and immense process applications (Ahmed et al 2019) are widely utilized alone or alongside other materials for the treatment of lead in water (Kumar et al 2019).…”