Copper removal from wastewater using spent-grain as biosorbent

Area of Science:

• Environmental Science
• Water Treatment
• Adsorption Technology

Background:

• Copper (II) ions are common pollutants in industrial wastewater.
• Effective and economical methods for removing heavy metals are crucial for environmental protection.
• Spent-grain, a byproduct of the whisky distilling industry, is an underutilized resource.

Purpose of the Study:

• To investigate the efficacy of spent-grain as a biosorbent for Cu(II) ion removal.
• To determine the adsorption capacity and kinetics of spent-grain for Cu(II).
• To evaluate the performance of spent-grain in treating real industrial wastewater.

Main Methods:

• Batch adsorption experiments to study isotherm and kinetic models.
• Langmuir isotherm and pseudo-second-order kinetic models were applied.
• Column studies were conducted to assess removal efficiency under various conditions.
• Wastewater from the whisky distilling industry (spent-lees) was used for real-world testing.

Main Results:

• The maximum adsorption capacity of spent-grain for Cu(II) was 10.47 mg/g at pH 4.2.
• Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics.
• Spent-grain showed reduced Cu(II) uptake capacity when treating actual distillery wastewater compared to synthetic solutions.
• EDTA presence and solution pH significantly affected Cu(II) removal.

Conclusions:

• Spent-grain is a cost-effective and efficient biosorbent for removing Cu(II) ions from aqueous solutions.
• Its application in treating wastewater from the whisky distilling industry is promising.
• Further research can optimize spent-grain for industrial wastewater treatment.