Cleaning & Decontamination

Use Cases 

How effective are colloidal gas aphrons made with natural surfactants in treating dye-contaminated wastewater ? 

Reference: Pal, P., Corpuz, A. G., Hasan, S. W., Sillanpää, M., & Banat, F. (2021). Simultaneous removal of single and mixed cationic/anionic dyes from aqueous solutions using flotation by colloidal gas aphrons. Separation and Purification Technology, 255, 117684.

In this study, Ziziphus spina-christi (ZSC) leaf extracts as a natural surfactant and anionic sodium dodecyl benzenesulfonate (SDBS), a synthetic surfactant, were used to prepare CGAs to remove single and mixed cationic and anionic dyes from aqueous solutions. Thanks to the Cell Size Analysis software (CSA by TECLIS), the mean diameter of colloidal gas aphrons (CGA) was measured: <100 µm for ZSC and 117 µm for SDBS.

Moreover, decontamination experiments using methylene blue (MB) and/or anionic dye (Congo red, CR)  showed that CGAs generated from the natural surfactant were effective in removing dyes with different charges in the two-step successive flotation process. Mixed dyes were also successfully removed using CGAs produced from anionic SDBS surfactant solution in a one-step flotation process.

 

TECLIS product: FOAMSCAN™ foam analyzer, Cell Size Analysis software (CSA)

Key words: Mixed dyes, Colloidal gas aphrons, Natural surfactant, Anionic surfactant, Flotation

What are the surface properties, the foaming and the emulsifying properties of amino acid surfactants used in decontamination application?

 

Reference: Yang, J., Zhou, Y., Yang, B., Huang, L., Liu, C., Han, F., & Xu, B. (2020). Comparative Study on the Syntheses and Properties of Three N‐lauroyl Aromatic Amino Acid Surfactants. Journal of Surfactants and Detergents, 23(4), 687-695.

Amino acid surfactant comes from renewable resources and is used as an environmentally friendly surfactant.

 

In this study, three N-lauroyl aromatic amino acid surfactants, namely, sodium N-lauroyl phenylalaninate (SLP), sodium N-lauroyl tyrosinate (SLTy), and sodium Nlauroyl  tryptophanate (SLTr), were synthesized and a comparative study of the three surfactants in terms of surface, foam, and emulsifying properties and decontamination performance was conducted.

TECLIS product: FOAMSCAN™ foam analyzer

Key words: Amino acid surfactant, Surface property, Foam properties, Emulsifying property, Decontamination performance

Can flotation using a pH sensitive surfactant

be used to extract  caesium ions for water decontamination ?

 

Reference: Micheau, C., Dedovets, D., Bauduin, P., Diat, O., & Girard, L. (2019). Nanoparticle foam flotation for caesium decontamination using a pH-sensitive surfactant. Environmental Science: Nano, 6(5), 1576-1584.

In  this paper, the authors investigated the Cs+  removal from an aqueous solution by flotation using a pH-sensitive foaming agent (Ethomeen). They showed the efficiency of this process and found that it is based on the fine control of the electrostatic interactions between the various species: Cu-PBAs and the recyclable pH responsive surfactant.

 

Moreover,  using a foam analyzer (FOAMSCAN™ by TECLIS), the foaming capacity was found to depend on the pH Value. These variations are correlated with the zeta-potential of the interface: maximum values when the zeta-potential at the surfactant monolayer is positive at low pH or negative at high pH, and minimum values when the zeta potential is  inferior to 10mV. Hence the charge increase of the surfactants interfaces the foaming capacity mainly due to the repulsions between foam film interfaces.

TECLIS product: FOAMSCAN™ foam analyzer

Key words: Flotation, foaming capacity, pH sensitive surfactant