Researchers test carbon nanotubes and bacteria to combat microplastic pollution

Researchers are exploring new methods to combat the persistence of microplastics in the environment. A study conducted by University College London (UCL) investigated the use of carbon nanomaterials to accelerate the degradation of polyethylene (PE) in soil-plant systems.

Using an alfalfa-soil experiment, the UCL team found that multi-walled carbon nanotubes (MWCNTs) significantly enhanced surface oxidation of PE. At a concentration of 200 mg kg-1, MWCNTs achieved a 12.1% mass loss at the surface over 90 days. Graphene oxide (GO) also showed effectiveness, though to a lesser extent than MWCNTs.

In a separate study, research from Clemson University examined the use of the bacterium Pseudoalteromonas sp. NCIMB 2021 to improve microplastic removal from water. By leveraging the bacteria's ability to produce extracellular polymeric substances (EPS), microplastics can be embedded in a matrix to facilitate easier removal through coagulation and flocculation.

Testing showed that this biological approach reached a maximum removal capacity of 74% for high-density polyethylene (HDPE) under specific environmental conditions, including a temperature of 37°C. The method also showed varying efficiencies for other polymers, including PET (52%), polypropylene (51%), and PVC (43%).