Valorization of a poultry industry floated sludge as a raw material to produce char and activated carbon for pharmaceutical compounds adsorption.

This study was intended to valorize a floated sludge of a poultry slaughterhouse using it as a precursor to producing char and activated carbon, which were tested as adsorbents in removing ketoprofen and diclofenac sodium from the water. The addition of zinc chloride or calcium hydroxide was determinant for forming a porous carbonaceous structure with a high surface area in AC-FSP (656.54 m2 g-1), differently from that exhibited by the CHAR-FSP (8.11 m2 g-1). Kinetic and equilibrium studies indicated that the pseudo-second-order and the Sips models were suitable. The AC- FSP maximum adsorption capacity for ketoprofen and diclofenac sodium was 124.98 mg g-1 and 138.32 mg g-1, respectively. The adsorption was a spontaneous and endothermic process. It was concluded that AC-FSP is a more efficient and promising adsorbent than CHAR-FSP for the adsorption of drugs in contaminated wastewater. In addition, AC-FSP can be reused, maintaining good adsorption levels for about 5 cycles. Therefore, this study is aligned with the 2030 Agenda for global sustainability since converting waste (valueless) into an adsorbent is also directly linked to the circular economy and neutral carbon.

Augmented degradation of dyed organic pollutant using Fe2O3 supported on char formed from poultry slaughterhouse waste.

In this work, a novel support for an iron-based catalyst was prepared and employed for Ponceau 4R degradation by photo-Fenton reaction. To this, poultry waste was used for producing char, which was subsequently used to prepare the Fe2O3/Char composite. Process parameters, including catalyst dosage, pH, and hydrogen peroxide concentration, were investigated. The characterization analysis indicated that the textural properties of the composite were improved after impregnation with Fe2O3. The composite exhibited excellent catalytic activity, achieving a decolorization efficiency of 97% at 45 min and 81.06% organic carbon removal at 300 min. In addition, the material showed acceptable performance after four consecutive cycles. Furthermore, a scavenger test was performed to investigate the major reactive species involved in the Ponceau 4R oxidation, and a plausible mechanism for the respective reaction was projected. Therefore, the results of this research demonstrate that this material can be used as a potential catalyst for the abatement of dyed molecules from wastewater.

Preparation of chitin nanowhiskers and its application for crystal violet dye removal from wastewaters.

Chitin (Ch) and chitin nanowhiskers (ChNW) were prepared, characterized, and applied as adsorbent to remove crystal violet (CV) dye from aqueous solutions. Ch was obtained from shrimp wastes and submitted to acid hydrolysis in order to find ChNW. The increase in average pore size and the rod-like shape of ChNW were probably the main characteristics which contributed to the increase in adsorption potential, when compared with raw Ch. The adsorbent dosage considered more adequate was 5 g L-1, and the most suitable pH was 8.0. A pseudo-second-order model was adequate to represent the kinetic profile. Sips and Hill models were suitable to fit the equilibrium curves. The maximum adsorption capacity of CV on ChNW was 59.52 mg g-1, and the process was endothermic, favorable, and spontaneous. These findings indicated that ChNW have potential to be used as adsorbent in the treatment of colored wastewaters.

Preparation of carbonaceous materials from pyrolysis of chicken bones and its application for fuchsine adsorption.

Activated carbon and biochar were obtained from chicken bone (CB), characterized, and applied to remove basic fuchsine from aqueous media. The adsorbent dosage and pH effects were studied, as well as kinetic, equilibrium, and thermodynamic curves were constructed. The values of BET surface area and total pore volume were 108.94 m2 g-1 and 0.219 cm3 g-1 for the activated carbon and, 18.72 m2 g-1 and 0.075 cm3 g-1 for the biochar. The dye removal percentages were 93.63 and 55.38% when 2.5 g L-1 of activated carbon and biochar were used, respectively. The adsorption was favored using 0.5 g L-1 of adsorbent and pH of 7.0. Adsorption kinetics was well represented by the pseudo-second-order model. Langmuir model was the best to represent the equilibrium. Maximum adsorption capacity was 260.8 mg g-1, obtained using activated carbon. The process was endothermic, favorable, and spontaneous. Results showed that alternative carbonaceous materials can be obtained from chicken bones and used as adsorbents to treat colored effluents containing fuchsine.