Biosorption of Lead from Wastewater Using Fresh Water Algae Chlorella

Area of Science:

• Environmental Science
• Biotechnology
• Water Treatment

Background:

• Lead (Pb2+) ions are toxic pollutants commonly found in industrial wastewater.
• Conventional methods for lead removal can be costly and generate secondary waste.
• Biosorption using natural materials like algae offers a sustainable alternative for heavy metal remediation.

Purpose of the Study:

• To evaluate the efficacy of freshwater algae Chlorella as a biosorbent for lead ion removal from wastewater.
• To identify the functional groups on Chlorella responsible for lead ion adsorption.
• To determine the optimal conditions for lead biosorption and assess the applicability of adsorption isotherm models.

Main Methods:

• Fourier transform infrared (FTIR) spectroscopy was used to identify functional groups on Chlorella.
• Batch biosorption experiments were conducted to investigate the effects of contact time, biosorbent dosage, and pH.
• Langmuir and Freundlich adsorption isotherm models were applied to analyze the experimental data.

Main Results:

• FTIR analysis confirmed the presence of amino, carboxylic, hydroxyl, and carbonyl groups on Chlorella, facilitating lead ion binding.
• Optimal biosorption conditions were determined as a dosage of 10 g/L, pH 5, and a contact time of 100 minutes.
• The biosorption of lead ions onto Chlorella algae demonstrated a strong fit with the Freundlich isotherm model, indicated by a high correlation coefficient.

Conclusions:

• Chlorella is a highly effective and viable biosorbent for removing lead ions from contaminated wastewater.
• The functional groups present on the algae surface play a crucial role in the lead adsorption mechanism.
• The Freundlich isotherm provides an accurate model for describing lead biosorption by Chlorella, suggesting a multilayer adsorption process.