Detection and removing of lead from wastewater using chemical treatment of polyurethane foam waste: Batch and column experiments
A new inexpensive sorbent was prepared from the waste of polyurethane foam (PUF) which highly surface polarity and sorption capacity. PUF was modified by adding amino, chloro and hydroxyl groups to its matrix. The polyamine polyhydroxy polyurethane chloride (PPPC) was characterized by using elemental analysis (EA), bulk conductivity (BC,σ), infrared/ultraviolet/visible spectra (IR/UV/Vis), pH point zero charge (pHZCP), thermal analysis (TGA/DTA/DSC), scanning electron microscope (SEM) and X-ray diffraction (XRD). The PPPC owned improved stability in acidic/alkaline solutions and organic solvents. The pHZPC of PPPC was 5.1 and the maximum values of ΔpH of PPPC are + 1.5 and –3.8 at pH 3.2 and pH 8.3. The σ of PPPC was 2.6×10–5 Ω–1m–1. PPPC contains several active groups (NH2, Cl, OH, C=O, C=C, and C-O-C) which classified as an effective sorbent for the solid-phase extraction (SPE) of Pb(II) ions from wastewater. The removing rate of the Pb(II) ions onto PPPC was very fast with half-life time (t1/2) 1.13 min at pH range 3–7. The value of ΔΗ for the sorption Pb(II) ions were –22.9 kJ/mol; these revealed that the values the extraction process is exothermic in nature. The recovery percentage of Pb(II) ions are 99–105% with relative standard deviation (RSD) 2.49% (n = 7).