Characterization of pore-expanded amino-functionalized mesoporous silicas directly synthesized with dimethyldecylamine and its application for decolorization of sulphonated azo dyes

Anionic and Cationic Dyes Removal from Aqueous Solutions by Adsorption onto Synthetic Mg/Al Hydrotalcite-Like Compound

“…By plotting ln q e versus ln C e , the values of n and K F can be obtained from the slope and the intercept of the linear plot. The values of 1/n imply the type of isotherm and can be classified as irreversible (1/n = 0), favorable (0 < 1/n < 1) and unfavorable (1/n > 1) [28][29][30]. The obtained values of 1/n (0.1 < 1/n < 1) showed the favorable nature of both investigated dyes and the heterogeneity of the adsorbent sites at temperatures studied.…”

Review of the use of mesoporous silicas for removing dye from textile wastewater

“…Most adsorbents are easily available and inexpensive. How ever, their practical application has been limited by problems associated with their regeneration, disposal, poor mechanical stability, high sludge production and low removal effectiveness of a wide range of dyes (Crini 2006;Yang and Feng 2010a;Saratale et al 2011;Nguyen and Juang 2013). To overcome these disadvantages, which are a major challenge for dye treatment, various nano-adsorbents have been developed.…”

“…The capacity of dimethyldecylamine-MPS for adsorbing sulphonated azo dye of 0.3 mg/g is gradually enhanced by decreasing the pH to less than 4. Increasing pH resulted in a decrease in adsorption capacity, presumably because of the deprotonation of the surface groups and protonation of the acidic functional groups of Azo dye, leading to an electrostatic repulsion between adsorbent and adsorbate (Yang and Feng 2010a). From the above it is clear that there is an optimum pH for adsorption and it tends to decrease rapidly at strongly acid or strongly alkaline pHs.…”

“…They are of interest because of their relatively large pores, which facilitate mass transfer, the very high surface area, which allows a high concentration of active sites per mass of dye and high mechanical stability (Tsoncheva et al 2007;Yang and Feng 2010b;Tseng et al 2012). In addition, it is possible to change their surface chemistry by anchoring various chemical functional groups onto pore walls, which are exceptionally selective and have a high capacity for adsorbing various dyes (Liu et al 1998;Taguchi and Schüth 2005;Chew et al 2010;Yang and Feng 2010a;Huang et al 2011b;Karim et al 2012). The three consecutive steps in the adsorption of dye by MPSs adsorbent are: (i) Transport of the dye to the external surface of the adsorbent (film diffusion).…”

“…The most frequently used equations for describing isotherms of the adsorption of dye by MPSs in solid/ liquid systems are the Langmuir (Joo et al 2009;Chen et al 2012;Chang et al 2013a;Liu et al 2013), Freundlich (Monash and Pugazhenthi 2009;Anbia and Salehi 2012), Redlich-Peterson (Monash and Pugazhenthi 2009;Yang and Feng 2010a;Wu et al 2012) and Temkin Mahmoodi et al 2011). The mathematical equations of these models are presented in Table 7.…”