Preparation of Cellulose-Based Hydrogel Derived From Tea

Abstract

Cellulose was chemically extracted from tea residue and then a cellulose-based hydrogel was fabricated as an adsorbent to remove methylene blue from aqueous solutions. In this study, the cellulose-based hydrogel was prepared based on the copolymerization of acrylic acid (AA) on cellulose materials, with the addition of N,N'-methylene bis-acrylamide (MBA) as crosslinking agent, assisted by ammonium persulfate (APS) as initiator. The adsorption of the methylene blue (MB) solution onto the cross-linked cellulose-based hydrogel was studied by the static adsorption method under different conditions of pH, contact time, adsorbent dosage and initial methylene blue concentration. The results showed that for 50 mg/L of methylene blue solution as the initial concentration, the optimum pH was 10 and the adsorption efficiency was up to 98.89%. The analysis of the adsorption equilibrium isotherm strongly indicated that the adsorption by the hydrogel material was best fitted by the Langmuir model, with the maximum adsorption capacity of 41.67 mg/g. Furthermore, the cellulose-based hydrogel maintained high reusability and efficiency in methylene blue adsorption after desorption.

Using One-Step Acid Leaching for the Recovering of Coal Gasification Fine Slag as Functional Adsorbents: Preparation and Performance

“…∆H less than zero proved that the adsorption process of MB was exothermic. Furthermore, a performance comparison of adsorption effect on MB adsorption between the resulted functional adsorbent FS-N-2M-2 h-293K and previously reported adsorbents has been depicted in Table 6 [51][52][53][54][55]. The results of the analyses revealed that the novel functional adsorbent gains advantage over many other adsorbents, indicating that FS-N-2M-2 h-293K is a potential promising strategy for the treatment of MB wastewater.…”

Cellulose-Based Metallogels—Part 1: Raw Materials and Preparation

“…Cellulose for hydrogel production may be extracted from paper, food and agricultural wastes [77]. Rapeseed stalks [78][79][80], corn stalks [81][82][83], wheat straw [84], bagasse [85], flax fibers [86], thanaka heartwood [87], okara [88], tea leaf residues [89], sago pith [90], various fruit peel [91] and rinds [92], soybean stem [93], waste paper and cardboard [94][95][96][97][98] contain a sufficient amount of cellulose (Table 1) to extract and produce new functional materials, such as hydrogels. Thus, in agricultural wastes, such as annual plant residues, the content of cellulose varies in a wide range from 20 to 42% (Table 1) depending on the origin of the plant and the method of extraction.…”

“…Then, the raw material is undergone acid or alkali hydrolysis at high temperatures for several hours. The final treatment is delignification or bleaching with sodium chlorite or hypochlorite, chlorine dioxide, hydrogen peroxide, peracetic acid, and others, using one of these chemicals or their combination [78,87,89,90]. Other sources of cellulose may require additional extraction steps.…”