Modified biochar from Moringa seed powder for the removal of diclofenac from aqueous solution.

In this study, Moringa seed powder (MSP) was pyrolyzed at 450 °C to synthesize Moringa seed powder biochar (MSPB) and treated with phosphoric acid (H3PO4) to synthesize phosphate-modified Moringa seed powder biochar (MSPB-HPO) as an adsorbent for the removal of diclofenac (Dfc) from aqueous solution. Fourier transform infrared (FTIR) analysis, energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and pH point of zero charge (pHpzc) were conducted to give more insight into the adsorbent's properties. The SEM analysis showed the transformations in the surface morphology from the parent material to the synthesized materials after the thermal and acid treatment. EDS analysis revealed the variation in the elemental composition of the materials prior to and after adsorption of Dfc ions. The FTIR analysis showed changes and peak intensities of functional groups involved in Dfc removal. The pHpzc showed the charge carried by MSPB-HPO in different pH conditions. Isotherm data best matched the Sips model, and the pseudo-second-order model best described the adsorption kinetics. The maximum adsorption capacity of MSPB-HPO by Sips model was found to be 100.876 mg g-1.

Facile functionalization of cellulose from discarded cigarette butts for the removal of diclofenac from water.

In this study, cellulose nanocrystals (CNCs), and cellulose nanofibers (CNFs) were extracted from discarded cigarette butts (DCBs), and investigated for their efficiency for diclofenac (Dfc) removal from water. CNFs extraction process involved cleaving of acetyl group by alkali treatment and etched with phosphate ions (HPO) from phosphoric acid to obtain the variably charged HPO-CNFs. To obtain CNCs, sulfuric acid was used to cleave phenol moieties from CNFs under high temperature and agitation. SEM, FT-IR, SEM-EDS, Raman spectroscopy were used to analyze the physico-chemical properties of synthesized cellulose materials. The SEM images revealed the exfoliated fiber strands of CNFs after extraction procedure, and the difference in the crystal structure of CNCs30 and CNCs60. The EDS analyses revealed the presence of higher amount of carbon in DCBs compared to other forms of synthesized celluloses. The FT-IR analyses revealed functional group shifts and bond reductions after various treatment steps, while the HPO attachment on the CNFs surfaces was confirmed by the presence of PO bonds. Raman analyses revealed clear crystals in the CNCs60 compared to the other celluloses. The adsorption capacity of HPO-CNFs for diclofenac removal was found to be 107.90 mg g-1 and Langmuir model fitted well to the adsorption data.