Z-Loy^TM: sub-micron zero-valent iron offerings

OnMaterials has tailored the Z-Loy^TM product line to meet requirements for particular remediation strategies. Electrochemical reactions at the solid/liquid interface drive the redox reactions necessary for remediation to occur.

Z-Loy^TM is a sub-micrometer, zero valent metal powder suspension engineered for the in-situ remediation marketplace. Key features include:

• Small Particle Size: mean particle size below 250 nm
• Limited Aggregation: Provides optimum sub-surface mobility
• High Surface Areas: Tailorable from 1 to 30 m²/g. High surface area particles provide enhanced reaction kinetics.
• Biocompatible: often used as an amendment to bioremediation sites
• Range of Compositions & Reactivity: Most metals and metal alloys can be produced including compositions more reactive than iron
• Hydrogenation Catalysts: All Z-Loy^TM materials can be amended with Pd, Cu, and other hydrogenation catalysts
• Quantities: Anywhere from evaluation samples to multi-ton orders are available.

Figure 1: This SEM image shows discrete sub-micrometer and nanoparticles of 20 m²/g Z-Loy^TM-Fe.

Delivery vehicle

Z-Loy^TM is packaged as a concentrated non-aqueous suspension. The fully water miscible propylene glycol solvent is biocompatible and helps maintain the zero valent metal interface. Other NZVI products are shipped and stored in water; Z-Loy^TM is not exposed to water until injection into the sub-surface. Packaging in water is undesirable since metal reacts with water to form iron hydroxides, iron oxides, and hydrogen gas. These reactions consume metal and form insoluble oxyhydroxide matter that furthers aggregation issues.

Exceptional sub-surface mobility

Z-Loy^TM contains discrete, sub-micrometer and nanocrystalline particles. Conversely, other NZVI products (chemically precipitated, thermally reduced materials) contain multi-particle aggregates of smaller nanoparticles. Aggregates limit sub-surface mobility and constrain sub-surface product placement.

Z-Loy^TM is a sub-micron material with a composite structure having a zero-valent exterior and a less-dense ceramic core. The SEM image shown in Figure 1 gives an indication of the size, morphology, degree of discreteness. This material has a typical surface area of 15 +/-3 m²/g.

Z-Loy^TM is effective for accomplishing the destruction of:

• Most common aqueous-phase halogenated hydrocarbons including 1,1,1-TCA, CT, CF, PCE, and TCE
• Dissolved and Free-Phase concentrations
• Hexavalent chromium compounds.