Gold Recovery from E-Waste by Food-waste Amyloid Aerogels.

The demand for gold recovery from E-waste has grown steadily due to its pervasive use in the most diverse technical applications. Current methods of gold recovery are resource-intensive, necessitating the development of more efficient extraction materials. This study explores protein amyloid nanofibrils (AF) derived from whey, a dairy industry side-stream, as a novel adsorbent for gold recovery from E-waste. To do so, AF aerogels were prepared and assessed against gold adsorption capacity and selectivity over other metals present in E-waste. The results demonstrate that the AF aerogel has a remarkable gold adsorption capacity (166.7 mg/g) and selectivity, making it an efficient and adsorbent for gold recovery. Moreover, AF aerogels are efficient templates to convert gold ions into single crystalline flakes due to Au growth along the (111) plane. When used as templates to recover gold from E-waste solutions obtained by dissolving computer motherboards in suitable solvents, the process yields high-purity gold nuggets, constituted by approximately 90.8 wt.% gold (21-22 carats), with trace amounts of other metals. Life cycle assessment and techno-economic analysis of the process finally consolidated the potential of protein nanofibril aerogels from food side-streams as an environmentally friendly and economically viable approach for gold recovery from E-waste. This article is protected by copyright. All rights reserved.