Mechanisms of emerging contaminants removal by novel neem chip biochar

Harnessing a carbon-based material from food waste digestate for dye adsorption: the role of hydrogel beads in enhancing the material stability and regenerative capacity

“…The main functional groups of CM-HNO 3 are represented by peaks at 3205 cm −1 (bonded –OH groups), 1699 cm −1 (organic residues and carboxyl functional groups), 34 1581 cm −1 (the stretch vibration of CC), 35 1386 cm −1 (C–O stretching vibration), 32 and 1082 cm −1 (C–O stretching), 35 and the peaks between 520 and 906 cm −1 confirm the out-of-plane bending vibration of the –C–H bond on the benzene ring. 36…”

Chemical Modification of Neem (Azadirachta indica) Biomass as Bioadsorbent for Removal of Pb2+ Ion from Aqueous Waste Water

“…Figure 5 shows the FTIR spectra of the raw neem leaf, raw neem bark, NaOH extract, and citric acid modified samples were shown. For the raw neem leaf, the peaks at 1109, 1277, 1382, 2924, and 3445 cm -1 indicating ester C-O stretch [50], ether C–O stretch, nitro groups of N=O bend, H-C-H alkane asymmetric and symmetric stretch, and N-H (stretch similar to amines) functional groups were found. 1109, 1269, 1382, 2074, and 2368 cm -1 are showing ester C-O stretch [50], ether C-O stretch, nitro groups of N=O bend, and aldehydes with C-H stretch off C=O.…”

“…For the raw neem leaf, the peaks at 1109, 1277, 1382, 2924, and 3445 cm -1 indicating ester C-O stretch [50], ether C–O stretch, nitro groups of N=O bend, H-C-H alkane asymmetric and symmetric stretch, and N-H (stretch similar to amines) functional groups were found. 1109, 1269, 1382, 2074, and 2368 cm -1 are showing ester C-O stretch [50], ether C-O stretch, nitro groups of N=O bend, and aldehydes with C-H stretch off C=O. The absorption peak at 3458 cm -1 was due to –NH 2 (stretch similar to amines) [51].…”

“…The peaks remarkably decreased due to loss of polysaccharides. The samples FT-IR spectra show peak at around 3400 cm -1 due to O–H stretching vibration [50–52]. It can be seen that the FT-IR spectra indicated the presence of ionisable functional groups such as amino acids/amino groups, ether C-O stretch, and –CH 2 alkane’s asymmetric and symmetric stretch.…”

“…It can be seen that the FT-IR spectra indicated the presence of ionisable functional groups such as amino acids/amino groups, ether C-O stretch, and -CH 2 alkane's asymmetric and symmetric stretch. Ionization groups are functional groups that could perform as proton donor/ acceptor impacting the capability for a molecule to act as an acid or base [50]. This ionization generates empty active sites that could be substituted by metal ions [51].…”