Fate and toxicity of ferric ferrocyanide with cyanogenic and non-cyanogenic plant species

Abstract

Iron cyanide complexes are common contaminants at former manufactured gas plant sites. Although combined forms of cyanide have low toxicity, iron cyanide complexes can be decomposed to HCN through photolysis. This experiment was designed to evaluate the efficiency of phytoremediation and investigate potential toxic effect for iron cyanide complexes (i.e., ferric ferrocyanide) using the cyanogenic and non-cyanogenic plants in soil. Results showed that Sorghum (a cyanogenic plant) had the highest cyanide degradation in the root zone with the removal of approximately 32% while Switchgrass (a non-cyanogenic plant) and Flax (a cyanogenic plant) had 21% and 17% removal, respectively, with 4% dissipation in unvegetated soil. It was found that roots had higher cyanide concentrations than plant shoots. Water-soluble cyanide and the weak acid dissociable (WAD) fraction in the soil had increased at the end of the experiment, suggesting that plant may enhance the mobility and bioavailability of cyanide by root exudation. The risk associated with the leaching of cyanide compounds was assessed with the toxicity assay (Microtox). However, results indicated that the leachate from the pots was not toxic.

Nanoarchitectonics of Bimetallic MOF@Lab‐Grade Flexible Filter Papers: An Approach Towards Real‐Time Water Decontamination and Circular Economy

“…These cyanide contaminants created by MGP facility operations have severely contaminated the land and groundwater in the area. [19] For example, purifier wastes from former MGPs have been a typical source of cyanide contamination in the Midwest of the United States. These industrial facilities produced gas for many municipal needs between the years 1830 and 1950.…”

“…[18] Ultimately, the free cyanide could be a metabolic inhibitor and a phytotoxic substance in plant and animal species. [19,25] Therefore, the effluent wastewater that contains iron cyanide complexes from MGPs and other industrial wastes could cause severe ecological damage.…”

“…The novelty of the work lies in the development of robust freestanding filtration materials to purify PB dye-contaminated water. Though there are very few reports on the removal of PB from contaminated soils, [19,21] the adsorption of PB from simulated wastewater has not been explored to date. Herein, for the first time, bimetallic Mo/Zr-UiO-66 MOF incorporated flexible and freestanding nanoengineered filter papers were robustly applied to purify PB-contaminated water.…”