> Researchers have recovered gold from electronic waste. Their highly sustainable new method is based on a protein fibril sponge, which the scientists derive from whey, a food industry byproduct. ETH Zurich researchers have recovered the precious metal from electronic waste [in solution]
But not real gold. For that, you'd need whey protein;
From "Turning waste into gold" (2024) https://www.sciencedaily.com/releases/2024/02/240229124612.h... :
> Researchers have recovered gold from electronic waste. Their highly sustainable new method is based on a protein fibril sponge, which the scientists derive from whey, a food industry byproduct. ETH Zurich researchers have recovered the precious metal from electronic waste [in solution]
From "Brewing tea removes lead from water" https://news.ycombinator.com/item?id=43165095 :
> "Yeast-laden hydrogel capsules for scalable trace lead removal from water" (2024) https://pubs.rsc.org/en/content/articlelanding/2024/su/d4su0...
> "Application of brewing waste as biosorbent for the removal of metallic ions present in groundwater and surface waters from coal regions" (2018) https://www.sciencedirect.com/science/article/abs/pii/S22133...
Chitosan + Magnesium or Hydrogels; which given efficiency and sustainability as criteria?
"Simultaneous ammonium and phosphate removal with Mg-loaded chitosan carbonized microsphere: Influencing factors and removal mechanism" (2023) https://www.sciencedirect.com/science/article/abs/pii/S00139...
Supporting Information for "Molecular Insights into Novel Struvite– Hydrogel Composites for Simultaneous Ammonia and Phosphate Removal" (2025) https://acs.figshare.com/ndownloader/files/54930495