Effect of chromophore type on efficiency of reactive dye removal using polyamidoamine dendrimer

In this study, by selecting a sample of dyes from a wide variety of chromophores used in the production of reactive dyes (monoazo, bisazo, metal azo, phthalocyanine, anthraquinone, copper formazan and triphendioxazine), the colour removal performance of polyamidoamine (PAMAM) dendrimer in reactive dyes was statistically evaluated depending on the dye chromophore groups (and accordingly molecular weight and number of sulfo groups of the dye), dendrimer concentration and centrifugation time. When all the results were examined, it was observed that the colour removal efficiency was significantly lower in metalazo and copper formazan‐based reactive dyes, whereas colour removals ranging from 93% to 98% could be obtained in bisazo, triphendioxazine, monoazo, anthraquinone and phthalocyanine dyes. With the use of dendrimer, the best colour removal efficiencies occurred at pH 3. However, it was found that the centrifugation time of 15 min is sufficient for all dyes, and a longer centrifugation does not provide any additional benefit in terms of colour removal.