SciELO - Scientific Electronic Library Online

 
vol.38 issue5Natural organic matter (NOM) in South African waters: NOM characterisation using combined assessment techniquesThe distribution of inherent phosphorus in fifteen water treatment residues from South Africa author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Article

Indicators

Related links

  • On index processCited by Google
  • On index processSimilars in Google

Share


Water SA

On-line version ISSN 1816-7950
Print version ISSN 0378-4738

Abstract

MWANGI, Isaac W; NGILA, J Catherine  and  NDUNGU, Patrick. A new spectrophotometric method for determination of residual polydiallyldimethylammonium chloride flocculant in treated water based on a diazotization-coupled ion pair. Water SA [online]. 2012, vol.38, n.5, pp.707-714. ISSN 1816-7950.

Polydiallyldimethylammonium chloride (polyDADMAC) is a water-soluble cationic polyelectrolyte used for water treatment. Its residues in treated water are contaminants as they react with chlorine to produce a carcinogenic compound. Commonly-used techniques for quantification of the polycation, such as colloidal and potentiometric titration as well as Ή NMR, have poor sensitivity and detection limits. This paper describes a more sensitive UV spectrophotometric method for quantitative determination of residual polyDADMAC in treated water, through formation of an ion pair with (4-hydroxy-1-napthylazo) benzene-sulphonic acid (dye). The ion pair, which is a colloidal solid material, was characterised by FTIR, 13C NMR and Ή NMR techniques. The colloid materials formed with different concentrations of polyDADMAC were dissolved in either N,N-dimethylformamide or 1,4-dioxane, followed by determination with UV spectrophotometry. The wavelength of maximum absorption (λ ) was found to be dependent on the solvent used, with 1,4-dioxane showing a better linear range of 0.1-1.8 mg-l-1 polyDADMAC. Varying the pH of the solutions had no significant effect on λ max.

Keywords : Polydiallyldimethylammonium chloride; flocculant; UV spectrophotometry; (4-hydroxy-1-napthyl-azo) benzene-sulphonic acid; treated water.

        · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License