Removal of basic dyes from aqueous solutions with a treated spent bleaching earth

Pyrolysis of residual palm oil in spent bleaching clay by modified tubular furnace and analysis of the products by GC–MS

“…Absorption band in the region of 2970-2850 cm −1 corresponds to -CH 2 deformation and C-H stretching in C-CH 3, while ester carbonyl vibrations (C O) was found to be at absorption peak of 1745 cm −1 . These bands are characteristic of edible oil [13,22,24]. The said bands appeared only in the FTIR spectra of SBC, FBC-CPO, CPO, EO and DOC before pyrolysis.…”

“…All the FTIR spectra showed similar absorption bands characteristic of the clay structure. Bands near 3460 cm −1 with shoulder at 3646 cm −1 are attributed to absorption of interlayer water and stretching vibrations of structural hydroxyl respectively (vibration of O-H bond in Si-OH and HO-H vibration of the water molecules adsorbed on silica surface) [13,22,24]. and Si-O-Si [24,25].…”

“…CPO and EO showed weight loss of almost 100% meanwhile DOC and FBC showed weight loss of about 14% and 9% respectively. Samples analyzed with TGA-DTG were further subjected to heating until 1163 K. The percentage of weight loss for SBC, FBC-CPO, DOC and FBC increased 20-40% due to the removal of the hydroxyl group in silica bonding at higher temperatures [24,28]. Weight of CPO and EO remained the same even at 1163 K. The remaining non-pyrolyzable products at 1163 K from SBC, FBC-CPO, DOC and FBC amounting up to 80% could be due to unburned silica [13].…”

“…2a) and FBC-CPO showed four weight loss steps. The first endothermic weight loss is due to removal of adsorbed water molecules and chemically bonded OH − groups [24,28]. The second step showing a major endothermic weight loss is mainly associated to decomposition and burning of organic content of the samples (evolution of volatile products or oils).…”

Synthesis and characterization of Mg–Fe layer double hydroxides and its application on adsorption of Orange G from aqueous solution

“…If the plot does not pass through the origin, this is indicative of some degree of boundary layer control and intra particle diffusion is not the sole rate limiting step. The intercept values are 37.90 and 65.00 mg g −1 for LDH and CLDH, respectively (Table 1), which indicates that pore diffusion is not rate limiting step [37][38][39][40].…”