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There is a significant need for an inexpensive biological approach to recover specific, targeted metals and other target materials in e-waste or other aqueous solutions that requires minimal input of resources, including energy. This invention is a method of removing or adsorbing a target substance or material, for example, a metal, non-metal toxin, dye, or small molecule drug, from solution, by functionalizing a substrate with a peptide configured to selectively bind to the target substance or material and to bind to the substrate. The substrate is fungal mycelium, and the naturally-occurring or bioengineered peptide is called a target-binding domain, which is chemically bonded to a selected solid substrate. The target chemical species binds to the target-binding domain and is removed from solution. The target can be any chemical species dissolved or suspended in the solution. Capture of the target by the substrate can isolate and allow removal of the target substance from solution, or for utilization in water filtration, or recovery of targeted chemical species from solution, particularly aqueous solution applications. The peptides used include (i) fusion peptides and/or proteins containing metal-binding domain sequence and optionally containing substrate-binding domain sequence; (ii) fusion peptides/proteins containing a metal-binding domain and a chitin-binding domain; and (iii) nucleic acids encoding fusion peptides and/or proteins containing metal-binding domain sequence. The technology enables simple scale up to a level that could be successfully implemented in an environment with limited resources, such as on a space mission or on earth in developing countries with poor access to clean water.

NASA and the US Army Engineer Research and Development Center (ERDC) co-developed advanced graphene materials designed to improve the filtration rate of spacecraft water contaminants which could significantly extend the service life of existing media filtration beds. Traditional granulated activated carbon (GAC) media is characterized by having a polymodal pore structure and contains micro-, meso-, and macropores that trap and contain contaminants. By using the referenced method to add graphene nanoparticles to an existing GAC filtering substrate, additional filtering can be achieved due to graphene’s mostly mesoporous nature. A high-level overview of the graphene loading process is thus: The unloaded graphene nanoparticles are mixed with a water-based graphene suspension for an extended time at room temperature. This “graphene bath” process is repeated several times before the now graphene-loaded (up to ~ 1% by mass) filtration media is dried and prepared for packing into a filter cartridge. The graphene suspension used during the loading process may be reused multiple times, reducing consumables in the process. Laboratory testing has shown a 40x improvement in contaminant removal per mass of the absorbent (i.e., graphene) over the state of the art (granulated activated carbon) at lower loading rates, suggesting significant promise of the treated filter media posing a potential solution to the demands of an entire mission lifecycle. Potential commercial applications for this graphene loading method may lay in four distinct market segments that rely on filtration media beds (outside of aerospace): industrial filtration such as ultra-pure water refining for the semiconductor industry, commercial filtration, residential filtration, and filtration-as-a-service. Graphene nano-particles’ tunable pore sizing, in conjunction with this loading method, could offer tailored filtration boosting for existing water filter substrates. The Graphene Loading Method for Water Filtration Media has a technology readiness level (TRL) 4 (Component and/or breadboard validation in laboratory environment), and it is now available for patent licensing. Please note that NASA does not manufacture products itself for commercial sale.