Surface modified mesostructured iron oxyhydroxide: synthesis, ecotoxicity, and application

Area of Science:

• Environmental Science
• Materials Science
• Chemistry

Background:

• Toxic heavy metal anions like arsenic and chromium pose significant risks to aquatic ecosystems and human health.
• Conventional methods for heavy metal removal can be inefficient or generate secondary pollution.

Purpose of the Study:

• To investigate the efficacy of mesoporous iron oxide, specifically amine-functionalized FeO(x), for removing arsenic and chromium from aqueous solutions.
• To evaluate the toxicity of the developed adsorbents.

Main Methods:

• Mesoporous iron oxide structures were synthesized and characterized using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and transmission electron microscopy (TEM).
• Adsorption experiments were conducted to determine the removal capacities for arsenic and chromium.
• Acute toxicity tests were performed on Daphnia magna using prepared adsorbent suspensions.

Main Results:

• Amine-functionalized mesoporous iron oxide exhibited maximum adsorption capacities of 33.51 mg/g for arsenic and 25.05 mg/g for chromium.
• The 24-hour EC50 values indicated that amine-functionalized meso-FeO(x) has significantly lower toxicity compared to Fe3O4.
• Toxicity concerns associated with adsorbent spills can be mitigated by using amine-functionalized meso-FeO(x) at concentrations up to 1500 mg/L.

Conclusions:

• Modified mesoporous iron oxide, particularly the amine-functionalized variant, is a promising adsorbent for the effective removal of toxic heavy metal anions.
• The low toxicity profile of amine-functionalized meso-FeO(x) enhances its suitability for practical environmental applications.
• This research offers a viable strategy for remediating heavy metal-contaminated water sources.