Cyanobacteria control using Cu-based metal organic frameworks derived from waste PET bottles

Area of Science:

• Environmental Science
• Materials Science
• Aquatic Toxicology

Background:

• Copper sulfate (CuSO4) effectively controls harmful algal blooms but poses risks to non-target aquatic organisms.
• There is a critical need for non-toxic and sustainable alternatives for managing algal proliferation.

Purpose of the Study:

• To synthesize and evaluate the efficacy of copper-based metal-organic framework (Cu-BDC MOF) chips as an environmentally safe algaecide.
• To assess the toxicity of Cu-BDC MOF chips to aquatic invertebrates.

Main Methods:

• Cu-BDC MOF chips were synthesized using waste polyethylene terephthalate (PET) bottles.
• The inhibitory effect of Cu-BDC MOF chips on *Microcystis aeruginosa* was compared to CuSO4.
• Acute toxicity tests (48 h) were performed on *Daphnia magna*.

Main Results:

• Cu-BDC MOF chips demonstrated efficient inhibition of *Microcystis aeruginosa*, comparable to CuSO4.
• Unlike CuSO4, Cu-BDC MOF chips exhibited no acute toxicity to *Daphnia magna*.
• Reactive oxygen species generated by Cu-BDC MOF and Cu2O were identified as the mechanism for algal growth inhibition.

Conclusions:

• Environmentally safe Cu-BDC MOF chips are a promising sustainable agent for controlling harmful algal blooms.
• This novel material offers an effective and non-toxic alternative to conventional algaecides like CuSO4.
• Utilizing waste PET bottles for MOF synthesis adds a valuable recycling component to this solution.