Red algae purifying polluted water.

Lead Gone Green: How Algae Could Revolutionize Wastewater Treatment

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Theo Raines in Climate & Environment August 2025 • 4 min read.

"Discover the groundbreaking potential of red algae in removing lead and other heavy metals from contaminated water sources, paving the way for sustainable and cost-effective environmental solutions."


Water pollution from heavy metals is a critical environmental and health issue worldwide. Industries like petroleum refining, mining, and electroplating release wastewater contaminated with dangerous substances, including lead (Pb), chromium (Cr), zinc (Zn), and cadmium (Cd). If these pollutants are not properly managed, they can accumulate in the food chain, posing significant risks to human health and the environment.

Traditional methods for removing heavy metals from wastewater, such as ion exchange, chemical precipitation, and membrane filtration, often prove ineffective or prohibitively expensive, particularly when dealing with low concentrations of contaminants. These methods also come with operational complexities and substantial land requirements.

Adsorption, however, stands out as a promising alternative. It's cost-effective and offers flexibility in both operation and design. The process is reversible, meaning that the adsorbent material can be regenerated for reuse. Activated carbon, a material known for its high efficiency in adsorption, is now being explored with a sustainable twist: using red algae as its source.

Why Red Algae Could Be the Future of Clean Water: The Science Behind Gracilaria Changii

Red algae purifying polluted water.

Researchers are increasingly interested in finding cheaper and more sustainable alternatives to commercial activated carbon. Materials that require minimal processing, are byproducts of other industries, or are abundant in nature are ideal candidates. Macroalgae, including red algae, have emerged as a promising option due to their small, uniform particle size and numerous metal-binding sites on their cell walls.

One specific type of red algae, Gracilaria changii, is particularly abundant in coastal areas of Oceania, Africa, and Asia, especially Malaysia. This makes it a readily available and potentially cost-effective resource for wastewater treatment. A new study has examined the ability of G. changii-derived activated carbon to remove lead (Pb(II)) from aqueous solutions.

  • Preparation of Activated Carbon: The red algae biomass is carefully washed to remove impurities, dried, ground, and sieved to a specific particle size. It's then pre-treated with hydrochloric acid (HCl) before undergoing thermal activation at 300°C to create the activated carbon.
  • Batch Adsorption Experiments: These experiments are conducted to assess the effectiveness of the activated carbon in removing lead from water. Factors such as pH, contact time, initial lead concentration, and the amount of activated carbon used are carefully controlled and measured.
  • Analysis Techniques: Scanning electron microscopy (SEM) is used to analyze the surface of the activated carbon, while Fourier transform infrared spectroscopy (FTIR) helps determine the functional groups involved in the adsorption process. The Brunauer-Emmett-Teller (BET) method is used to measure the surface area of the adsorbent.
The study's results demonstrated the potential of red algae-derived activated carbon for lead removal. The maximum lead uptake capacity was achieved at a pH of 6 and an operation time of 30 minutes. This indicates that Gracilaria changii can be a viable option for treating wastewater contaminated with heavy metals.

The Future is Green: Embracing Algae for a Cleaner Planet

The research confirms that macroalgae-derived activated carbon, particularly from Gracilaria changii, can be an efficient and low-cost adsorbent for removing lead ions from wastewater. As the world seeks more sustainable and environmentally friendly solutions, algae-based technologies offer a promising path toward cleaner water and a healthier planet. Further research and development in this area could revolutionize wastewater treatment and unlock the full potential of algae as a valuable resource.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1051/matecconf/201820303006, Alternate LINK

Title: Removal Of Lead Using Activated Carbon Derived From Red Algae (Gracilaria Changii)

Subject: General Medicine

Journal: MATEC Web of Conferences

Publisher: EDP Sciences

Authors: Mubeen Isam, Lavania Baloo, Nasiman Sapari, Idayu Nordin, Saba Yavari, Wesam Al-Madhoun

Published: 2018-01-01

Everything You Need To Know

1

Why is red algae, specifically *Gracilaria changii*, being considered for wastewater treatment?

Red algae, particularly *Gracilaria changii*, is being explored as a sustainable and cost-effective alternative to traditional methods for removing heavy metals like lead from wastewater. Its abundance in coastal areas of Oceania, Africa, and Asia makes it a readily available resource.

2

What are the drawbacks of traditional heavy metal removal methods in wastewater treatment, and how does adsorption using materials like *Gracilaria changii* address these issues?

Traditional methods like ion exchange, chemical precipitation, and membrane filtration can be ineffective or expensive, especially for low concentrations of contaminants. Adsorption using activated carbon from sources like *Gracilaria changii* offers a cost-effective and operationally flexible alternative.

3

Can you describe the preparation and analysis techniques used to assess *Gracilaria changii*'s effectiveness in removing lead from water?

The process involves several key steps. First, the *Gracilaria changii* biomass is washed, dried, ground, and sieved. It is then pre-treated with hydrochloric acid (HCl) and thermally activated at 300°C to create activated carbon. Batch adsorption experiments are conducted to test lead removal effectiveness under controlled conditions, using techniques like scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and the Brunauer-Emmett-Teller (BET) method for analysis.

4

How do pH levels and operation time affect the ability of *Gracilaria changii* to remove lead, and why is this important?

*Gracilaria changii*'s effectiveness as an adsorbent is significantly influenced by pH levels and operation time. Studies have shown that the maximum lead uptake capacity of *Gracilaria changii* is achieved at a pH of 6 and an operation time of 30 minutes. Understanding these factors is crucial for optimizing the algae's performance in wastewater treatment.

5

What is the future potential of using *Gracilaria changii* in wastewater treatment, and what further research is needed to fully realize its benefits?

The use of *Gracilaria changii* derived activated carbon offers a sustainable pathway towards cleaner water. Further research and development in algae-based technologies have the potential to revolutionize wastewater treatment, providing environmentally friendly solutions for a healthier planet. This involves optimizing the adsorption process, exploring different algae species, and scaling up the technology for industrial applications.

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