Application of polyurethane@salvadora persica composite for detection and removal of acidic and basic dyes from wastewater

26-11-2017 07:54

A novel, stable and inexpensive biosorbent@polymer composite was synthesized by coupling of the biosorbent (Salvadora persica roots, SPR) with polyhydroxy polyurethane foam (PPF). The SPR@PPF was characterized using different tools. It was clear that the surface of SPR@PPF contained nanocrystals particle dispersed in the amorphous phase and also contained 2.4 and 1.0 mmol/g of acidic and basic sites. Thermogravimetric curve showed two endothermic peaks at 304 and 396°C due to the cupling of SPR@PPF. The morphology (surface area, pore volume and pore radius) of SPR@PPF are 34.6 m2/g, 0.053 cm3/g and 15.4 Ǻ, respectively. The SPR@PPF has successfully utilized in removing of brilliant green (BrG; basic dye) and brilliant blue (BrB; acidic dye) from both acidic and alkaline wastewater. The SPR@PPF was proven efficient for the complete removal of BrG and BrB with a sorption capacity of 202.7 and 142.4 mg/g at pH values of 5–7 and 1–2, respectively. Sorption rate constant values (k1) are 0.09 and 0.23 min−1 and half-life (t1/2) are 11 and 4.3 min and the removal process is spontaneous (ΔG is −3.75 kJ/mol). The results sustained the suitability of SPR@PPF as efficient sorbent for the dyes removing.

 Keywords: Polyurethane, Salvadora persica, Removal, Dyes, Brilliant green. Brilliant blue