Interaction between Haematococcus pluvialis microalgae and lead nitrate: lead adsorption from water

Area of Science:

• Environmental Microbiology
• Biotechnology
• Aquatic Toxicology

Background:

• Lead contamination poses significant risks to aquatic ecosystems and human health.
• Developing cost-effective and efficient methods for lead removal from wastewater is crucial.
• Microalgae, such as Haematococcus pluvialis, are increasingly explored for bioremediation applications.

Purpose of the Study:

• To investigate the physiological responses of Haematococcus pluvialis to lead toxicity.
• To evaluate the potential of Haematococcus pluvialis as a biological adsorbent for lead removal.
• To determine the optimal conditions for lead adsorption by this microalga.

Main Methods:

• Cultivation of Haematococcus pluvialis in BG11 medium.
• Exposure to varying lead nitrate concentrations (10, 50, 200 mg/L).
• Assessment of physiological indicators (growth rate, pigments, protein, MDA) and lead adsorption capacity.

Main Results:

• Lead toxicity decreased growth rate, chlorophylls, carotenoids, and total protein, while increasing malondialdehyde (MDA).
• Astaxanthin content showed a variable response to lead exposure.
• Maximum lead adsorption of 98.69% was achieved under specific conditions (pH 6, 1 g/L adsorbent dose, 25 mg/L lead, 25°C, 120 min).

Conclusions:

• Haematococcus pluvialis exhibits sensitivity to lead toxicity, providing insights into its physiological stress responses.
• This microalga demonstrates significant potential as a low-cost, efficient biosorbent for lead removal from contaminated water.
• The findings support the use of Haematococcus pluvialis in wastewater treatment strategies for heavy metal remediation.