Mercury Removal from Acidic Waste Solutions Using a Thiol Functional Organo‐ceramic Adsorbent

Abstract

Removal of mercury from highly acidic (1–2 M acid concentrations) waste solutions using a novel thiol‐functionalized organo‐ceramic adsorbent (SOL‐AD‐IV) has been investigated. The viability of mercury extraction was tested by employing Idaho National Engineering and Environmental Laboratory (INEEL) aluminum calcine and sodium bearing waste (SBW) surrogates. A maximum equilibrium uptake capacity of 740 mg/g in the 1–2 M acid concentrations was found, indicating a 1:1 adsorption ratio between Hg(NO₃)₂ ⁰ and thiol (SH). Loss of uptake activity due to high contents of aluminum, nitrate, and hydrogen ions was not evident. Over 99.7 wt% extraction efficiency was observed up to 4 M HNO₃ solutions. Rapid kinetics were observed with an extraction efficiency of >91 wt% within 5 min of reaction time. Dynamic adsorption of mercury on a fixed bed demonstrated a removal capacity of 680 mg/g and effluent concentrations as low 0.005 mg/L. Results showed applicability of this material for effective removal of mercury from highly acidic waste solutions.

Keywords:

• Mercury
• Removal
• Thiol

Acknowledgment

The financial support of the U.S. EPA NRMRL through Grant No. GR828570‐01‐0 and NSF through Grant No. CTS‐0120204 are gratefully acknowledged.