Carbon disulfide removal by zero valent iron

Area of Science:

• Environmental Chemistry
• Water Remediation Technologies
• Materials Science

Background:

• Carbon disulfide (CS2) is a prevalent groundwater contaminant.
• Zero valent iron (Fe0) is a promising material for in-situ water remediation.
• Understanding the reaction kinetics of Fe0 with CS2 is crucial for effective treatment design.

Purpose of the Study:

• To evaluate the efficacy of zero valent iron (Fe0) for removing carbon disulfide (CS2) from water.
• To investigate the reaction kinetics and mechanisms of CS2 removal by Fe0.
• To determine the applicability of Fe0 in permeable reactive barriers for groundwater remediation.

Main Methods:

• Mineralogical analysis of Fe0 filings and cross-sections.
• Batch and column testing to examine CS2 removal kinetics.
• Kinetic batch tests at varying temperatures to determine activation energy.
• Surface area normalization of rate constants.

Main Results:

• Fe0 effectively removes CS2 from water, forming iron sulfide.
• CS2 removal by Fe0 is rapid and follows pseudo-first-order kinetics.
• A linear relationship exists between the observed rate constant and Fe0 surface area concentration.
• The reaction kinetics are surface-controlled, with an apparent activation energy of 37 +/- 2.3 kJ mol(-1).
• Specific reaction rate constants (k(SA)) are consistent across batch and column tests.

Conclusions:

• Zero valent iron is an effective medium for the remediation of CS2-contaminated groundwater.
• The kinetics of CS2 removal by Fe0 are governed by chemical surface reactions.
• The derived specific reaction rate constants provide a valuable basis for designing permeable reactive barriers for CS2 treatment.