An Active Absorbent for Cleanup of High-Concentration Strong Acid and Base Solutions

• Main Authors: Nara Han, Sol Park, Byung Kwon Kaang, Wooree Jang, Hye Young Koo, Won San Choi
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Materials
• Subjects: chemical absorbents; iron oxide; strong acid and base; drop test; dust test
• Online Access: https://www.mdpi.com/1996-1944/12/20/3389

There is significant interest in developing novel absorbents for hazardous material cleanup. Iron oxide-coated melamine formaldehyde sponge (MFS/IO) absorbents with various IO layer thicknesses were synthesized. Various other absorbents were also synthesized and compared to evaluate the absorption capability of the MFS/IO absorbents for strong acid (15%, v/v) and base (50%, m/m) solutions. Specifically, absorbent and solution drop tests, dust tests, and droplet fragment tests were performed. Among the various absorbents, MFS/IO absorbents possessing a needlelike surface morphology showed several unique characteristics not observed in other absorbents. The MFS/IO absorbents naturally absorbed a strong base solution (absorption time: 0.71−0.5 s, absorption capacity: 10,000−34,000%) without an additional external force and immediately absorbed a strong acid solution (0.31−0.43 s, 9830−10,810%) without absorption delay/overflow during absorbent and solution drop tests, respectively. The MFS/IO absorbents were also demonstrated to be ideal absorbents that generated fewer dust particles (semiclass 1 (ISO 3) level of 280 piece/L) than the level of a clean room (class 100). Furthermore, the MFS/IO absorbents were able to prevent the formation of droplet fragments and solution overflow during the solution drop test due to their unique surface morphology and extremely high absorption speed/capacity, respectively.