Decolorization of triphenylmethane dyes by hydroponically grown sunflowers (Helianthus annuus L.)

Synthetic dyes have been a serious source of water contamination in many parts of the world. There is growing interest in using higher plants to clean up contaminated sites using phytoremediation techniques. We explore the potential of phytoremdition triphenylmethane dyes by sunflowers seedling. Two triphenylmethane dyes, Cresol red (CRS) and Bromophenol blue (BPB) did not inhibit the transpiration and the growth of sunflowers which grown in 20g/L, 40 mg/L and 80 mg/L triphenylmethane dyes solution. The decolorization rate of triphenylmethane dyes by sunflowers varied with the dyes and dye concentration. The maximum, minimum and average value of the decolorization rate of those dyes at three concentrations in 15 days was 80.1%, 33.3% and 55.5%. The average adsorption rate of CRS and BPB was 5.9% and 9.5% respectively. Desorption test result showed adsorption play an important role on the removal of the dyes. The significant difference of the apparent TSCF of sunflower for CRS and BPB showed that the removal ability of sunflower to triphenylmethane dyes is related to the specific chemical and physical property of the dye. It was concluded that sunflowers can efficiently decolorize wastewater containing triphenylmethane dyes.