A systematic study of cellulose-reactive anionic dye removal using a sustainable bioadsorbent
Fitfety M Teshager1, Nigus G Habtu1, Kibret Mequanint2
1Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Ethiopia.
Chemosphere
|May 26, 2022
Summary
Water hyacinth root powder (WHRP) effectively removes anionic blue dye from textile wastewater. This sustainable bioadsorbent achieves high removal efficiency and capacity, offering a low-cost solution for dye-contaminated water treatment.
Area of Science:
- Environmental Chemistry
- Materials Science
- Water Treatment Technologies
Background:
- Textile finishing utilizes cellulose-reactive anionic dyes, generating significant wastewater requiring treatment.
- Developing nations with substantial cotton-based textile industries need cost-effective and sustainable adsorbents.
- Existing wastewater treatment methods can be expensive and complex, necessitating innovative solutions.
Purpose of the Study:
- To investigate the efficacy of water hyacinth root powder (WHRP) as a bioadsorbent for removing reactive blue dye from aqueous solutions.
- To optimize adsorption conditions including pH, adsorbent dose, dye concentration, particle size, mixing speed, and temperature.
- To analyze the adsorption mechanism using isotherm, kinetic, and thermodynamic models.
Main Methods:
- Preparation of a high specific surface area (670 m²/g) bioadsorbent from water hyacinth root powder (WHRP).
- Systematic study of adsorption parameters: pH (2-8), dose (1-6 g/L), dye concentration (50-500 mg/L), particle size (50-1000 μm), mixing speed (100-200 rpm), and temperature (22-60 °C).
- Evaluation of adsorption isotherms (Langmuir, Temkin), kinetics (pseudo-second-order), and thermodynamics (Gibbs energy, enthalpy).
Main Results:
- WHRP achieved approximately 99% removal of reactive blue dye, primarily due to lignin polyphenol protonation at pH 2.
- Maximum adsorption capacity reached 128.8 mg/g under optimal conditions (1 g/L WHRP, 500 mg/L dye).
- Adsorption was favored by increased adsorbent dose, decreased particle size, increased mixing speed, and lower temperatures. Data fitted well with Langmuir and Temkin models, and pseudo-second-order kinetics.
Conclusions:
- Sustainable and abundant water hyacinth root powder (WHRP) is a highly efficient adsorbent for reactive blue dye removal.
- The adsorption process is spontaneous and exothermic, with a complex mechanism involving multiple steps.
- WHRP presents a scalable and eco-friendly solution for treating dye-contaminated wastewater, particularly beneficial for developing countries.
