Removal of nickel from aqueous solutions using crab shells

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Chitosan, derived from crab shell waste, is a biocompatible material.
• Pollution of water bodies with heavy metals like nickel is a significant environmental concern.
• Developing cost-effective and sustainable adsorbents is crucial for water remediation.

Purpose of the Study:

• To investigate the efficacy of partially converted crab shell waste as an adsorbent for nickel removal from aqueous solutions.
• To evaluate the kinetics and influencing factors of nickel sorption onto chitosan-based materials.

Main Methods:

• Utilizing partially converted crab shell waste, rich in chitosan, as an adsorbent.
• Conducting batch experiments to assess nickel uptake from water.
• Analyzing the sorption mechanism and the effect of pH and various anions.

Main Results:

• Partially converted crab shell waste demonstrated successful and rapid nickel removal, with sorption primarily occurring within 5 minutes.
• The sorption mechanism was complex, not fitting standard Langmuir or Freundlich models.
• Nickel uptake capacity showed minimal sensitivity to variations in pH and the presence of common anions (chloride, bromide, fluoride, acetate, sulfate, nitrate, phosphate).

Conclusions:

• Partially converted crab shell waste is a highly effective and rapid adsorbent for nickel removal.
• The material's performance is robust, showing little interference from common environmental factors like pH and anions.
• Chitosan from crab shells presents a sustainable and economical solution for nickel remediation in water treatment.