The Use of Chitin from the Molts of Mealworm (Tenebrio molitor) for the Removal of Anionic and Cationic Dyes from Aqueous Solutions

Abstract

The possibility of using chitin from the molts of an insect–ealworm (Tenebrio molitor) to remove anionic (RB5, RY84) and cationic dyes (BV10, BR46) from aqueous solutions was investigated. The scope of the research included, among others: Characteristics of chitin from mealworms (FTIR, SEM, pHPZC), the effect of pH on sorption efficiency, sorption kinetics (pseudo-first, pseudo-second order, intramolecular diffusion models) and the determination of the maximum sorption capacity (Langmuir and Freundlich models). The sorption efficiency of anionic dyes on chitin from mealworm was the highest at pH 2–3, and for cationic dyes at pH 6. The equilibrium time of sorption of anionic dyes was 240–300 min and for cationic dyes it was 180–240 min. The experimental data on dye sorption kinetics was best described by the pseudo-second order model. The maximum sorption capacity of chitin from the mealworm for the anionic dyes RB5 and RY84 was 121.15 mg/g and 138.55 mg/g, respectively, and was higher than with some carbon-based materials (literature data). In the case of cationic dyes, the sorption capacity of the tested chitin was lower and reached 3.22 mg/g and 59.56 mg/g for BV10 and BR46, respectively.

The Use of Chitin for the Removal of Nitrates and Orthophosphates from Greenhouse Wastewater

“…The characteristics of the FTIR spectrum as well as the SEM analysis used in the study of the chitin flakes were presented in our previous article [ 46 ]. SEM photos of CH are also included in the Supplementary Materials (Figures S3 and S4) .…”

The Pulsed Electric Field Treatment Effect on Drying Kinetics and Chosen Quality Aspects of Freeze-Dried Black Soldier Fly (Hermetia illucens) and Yellow Mealworm (Tenebrio molitor) Larvae

“…The absorbance peak observed close to 3280 cm −1 contributes to the stretching vibrations of O-H bond of hydrophilic compounds, e.g., amino acids or reducing sugars as well as N-H bond stretching vibrations from the amide A group [59,60]. A weak peak around 3000 cm −1 in dried T. molitor may have contributed to the acetamide functional group of chitin fraction [61] and also the O-H bond stretching vibrations of polysaccharides [45], which are a characteristic component of T. molitor. Moreover, the current study presented the PEF treatment as influencing the FTIR absorbance.…”

“…As before, the effect of PEF utilization on the absorbance value of the T. molitor FTIR spectra was observed. The strong peaks found at 2920 and 2850 cm −1 are responsible for the symmetric and asymmetric C-H bond stretching vibrations of -CH 2 group, characteristic of polysaccharides and lipids [45,61]. The peak at 2924 cm −1 is related to the C-H bond of the amide B group [60,63].…”

The Use of Exoskeletons and Molts of Farmed Mealworm (Tenebrio molitor) for the Removal of Reactive Dyes from Aqueous Solutions

“…Chitinbased sorption materials can prove very useful in the treatment of colored wastewater [14]. Compared with commercial activated carbons, chitin can boast higher sorption capacity towards anionic reactive dyes, which are the major component of colored wastewater [15]. These considerable sorptive properties of chitin are due to the high concentrations of acetamide and amine functional groups, which act as key sorption centers [16].…”

“…The mealworm (Tenebrio molitor) is one example of an insect farmed on a large scale for human consumption in many countries [18] and classified by the European Food Safety Authority as a "novel food" in June 2021. The chitin from mealworm molts-a waste product of mealworm farming-has very similar sorptive properties to commercial chitin from snow crab shells [15].…”