Direct and Indirect Ultrasonic-Assisted Preparation of Calcium Alginate Monolithic Pellets for the Removal of Methylene Blue from Aqueous Solution

Jia Jun Isaac Yong, Voon Loong Wong*, Swee Pin Yeap, Siew Shee Lim, Nurul Husna Mohd Yusoff

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Biosorption offers cost advantages over conventional treatment methods due to technical and financial constraints. In present paper, calcium alginate (CaAlg) monolithic pellets are investigated as biosorbents for the removal of methylene blue (MB) from aqueous solution in a batch mode. Direct and indirect ultrasonication was employed for the preparation of porous CaAlg pellets to enhance their removal efficiency (R%) and adsorption capacity (qe). In preliminary stage, the effectiveness of pure CaAlg pellets were evaluated based on different concentrations of sodium alginate (SA) (1wt%, 2wt%, and 3wt%). The synthesis of CaAlg pellets from 3wt% sodium alginate exhibited the highest adsorption capacity of 1.302 mg/g. Surface characterizations were studied to examine the morphology of the pure and ultrasonicated 3wt% CaAlg monolithic pellets using scanning electron microscopy (SEM) before and after adsorption. SEM images revealed that the surface of ultrasonic-assisted CaAlg monolithic pellets exhibits pores and fissures. Meanwhile, the experimental results indicated that the R% and qe of CaAlg pellets arranged in a descending order of direct ultrasonicated CaAlg (88.13%, 2.058 mg/g) > indirect ultrasonicated CaAlg (78.61%, 1.657 mg/g) > pure CaAlg (57.06%, 1.302 mg/g) at a batch adsorption condition of 250 rpm at 30 °C for 6 h. These pellets performed at least 21% better for MB removal than those synthesized in the absence of ultrasonic waves. Thus, the adoption of ultrasonication showed a promising potential for the synthesis of CaAlg monolithic pellets with improved adsorption properties to remove organic pollutants from dye wastewaters.

Original languageEnglish
Title of host publicationSustainable Development of Water and Environment
EditorsHan-Yong Jeon
Number of pages11
ISBN (Electronic)9783031425882
ISBN (Print)9783031425875
Publication statusPublished - 25 Oct 2023
Event6th International conference on Sustainable Development of Water and Environment 2023 - Hongkong, China
Duration: 18 Jun 202319 Jun 2023

Publication series

NameEnvironmental Science and Engineering
ISSN (Print)1863-5520
ISSN (Electronic)1863-5539


Conference6th International conference on Sustainable Development of Water and Environment 2023
Abbreviated titleICSDWE 2023


  • Biosorption
  • Calcium alginate
  • Homogeniser
  • Methylene blue
  • Ultrasonication bath

ASJC Scopus subject areas

  • Environmental Engineering
  • Information Systems

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