Oilseed Meals Find Use in Removing Heavy Metals from Contaminated Water

New research has shown that proteins harvested from sunflower seed meal and peanut meal can be used to filter heavy metals out of contaminated water, the New Atlas reported on June 28.  The study was conducted by scientists from Singapore’s Nanyang Technological University (NTU) and Switzerland’s ETH Zurich research institute.

The researchers started by extracting proteins from peanut and sunflower oilseed meal, and then wound the protein chains together to create nanoscale rope-like structures called protein amyloid fibrils. These fibrils were then combined with activated carbon, to form hybrid filtration membranes.  When these membranes were used to filter water contaminated with lead, platinum, and chromium, they were found to remove up to 99.89 percent of those heavy metals, allowing them to meet international drinking standards.  It was explained that the fibrils acted as “molecular sieves” that drew in and trapped heavy metal ions that were passing by. 

The scientists calculated that just 16 kg (35 lbs.) of sunflower protein would be required to filter the equivalent of an Olympic-sized swimming pool volume of water contaminated with 400 parts per billion of lead.  Furthermore, once the membranes become saturated, they can then be dried out and burned, with the trapped metals being left behind, allowing for more valuable metals, such as platinum to be recycled.  The filtration membranes thus could be a low-cost alternative to traditional technologies in water purification like reverse osmosis, and with bonus to provide another use for oilseed meals.