Phenol sorption by organoclays having different charge characteristics

Novel polymer/surfactant modified montmorillonite hybrids and the implications for the treatment of hydrophobic organic compounds in wastewaters

“…Zhu et al (2003) and Chen et al (2005) reported that as the surfactant loading increased gradually from 0.2 CEC to 2.5 CEC (i.e., from 20% to 250% of the montmorillonite's cationic exchange capacity), the K oc values of phenol and naphthalene could vary by over three times. Beside the surfactant loadings, the charge density of the montmorillonite can also significantly influence the K oc of a given HOC, and the general trend is that organo montmorillonites with higher charge density always have a larger K oc value Pálková et al, 2009;Shen, 2004;Zhu et al, 2007).…”

Chromium (VI) Adsorption Characteristics of Bentonite Under Different Modification Patterns

“…Previous studies showed that clays could be easily modifi ed [2], and that TOC (total organic carbon) content [3], interlayer spacing [4], surface hydrophobicity [5,6], and adsorption ability of organic contaminants and heavy metal salt ions [7][8][9] on the modifi ed clays were proven to increase signifi cantly.…”

Montmorillonite as a multifunctional adsorbent can simultaneously remove crystal violet, cetyltrimethylammonium, and 2-naphthol from water

“…For the organoclays synthesized with small, compact organic cations (e.g., tetramethylammonium, TMA), increasing the intermolecular distance of the intercalated cations will lead to larger exposed siloxane surface areas (main adsorption sites for HOC), which then can increase the adsorption capacity of this type of organoclays (Ruan et al, 2008;Shen, 2004). With respect to the organoclays synthesized with large, flexible organic cations (containing at least one long alkyl chains, e.g., CTMA), adjusting the arrangement of alkyl chain aggregates within the interlayer space of organoclays may also enhance their adsorption capacity (Zhu et al, , 2010.…”

“…These inorganic cations are exchangeable, making Mt efficient adsorbent for various cationic contaminants, such as heavy metals (Bailey et al, 1999;Bhattacharyya and Gupta, 2008;Krishna and Susmita, 2006), cationic dyes (Eren and Afsin, 2008;Gupta and Suhas, 2009;Rytwo and Ruiz-Hitzky, 2003), and cationic surfactants (Li and Rosen, 2000;Li et al, 2006;Ma and Zhu, 2007). After the adsorption of organic cations, interlayer space of Mt can change from hydrophilic to hydrophobic, and the resulting materials, also known as organoclays, have been used as efficient adsorbents for hydrophobic organic contaminants (HOC) (Chen et al, 2005;Ramesh et al, 2007;Rytwo and Gonen, 2006;Shen, 2002Shen, , 2004Zhu et al, 2007). Therefore, Mt can simultaneously remove both organic cations and HOC from wastewater, and it has been considered as a low-cost and high-efficient adsorbent for wastewater containing different organic contaminants (Ma and Zhu, 2007;Özcan et al, 2005;Rytwo and Gonen, 2006;Wei et al, 2009;Zhu and Ma, 2008).…”