HENCI Technology Abstract
Submitted by Ken Cross of Cross Consulting on March 30, 2005 in accordance with the NWRI’s “Call for
Papers” Document
In recent years, the efficacy and cost-effectiveness of 99.9%-Fe bimetallic nanoparticles (Fe/Pd, Fe/Ni, Fe/Pt, Fe/Cu, etc. –
hereafter FBNPs) for in in-situ catalytic breakdown of a large list of recalcitrant halogenated hydrocarbon and heavy metal
groundwater pollutants (often via sub-surface injection) has been well – documented. The desire to utilize this highly
effective catalytic action in a flow-through reactor for a growing list of higher-purity water treatment applications has been a
natural consequence of such success, and recently the water treatment community identified the last remaining major
obstacle to this effort: due to the small size of these FBNPs, there was no way to cost-effectively immobilize large
quantities of FBNPs in a reactor through which polluted water may pass (and come into intimate, prolonged contact with
the FBNPs) without entraining the nanoparticles themselves in the water stream, which completely defeats the purpose
of the intended technology by resulting in FBNP-polluted discharge water, not to mention waste of the expensive FBNPs.
High-Efficiency Nano-Catalyst Immobilization (HENCI) reactors were developed in Q4 2004 to readily immobilize these effective FBNPs in
continuous-flow reactors at FBNP packing densities ~3 generations greater than, and without the technical (and resulting financial)
drawbacks (including high energy requirements, pressure drops and/or residence times) of membrane impregnation, nano-cage structures,
resin-fixation, and related ‘classic’ FBNP immobilization technologies. As a result, these new FBNPs can finally be cost-effectively
deployed anywhere to remediate a host of at least 39 recalcitrant chlorinated hydrocarbons. Complete conversion of these species to
benign breakdown products such as chlorine gas, lower alkanes, and CO2 can now occur in minutes instead of months,
even when the influent concentrations are < 10ppm. As a combined technology, the HENCI / FBNP system chemically
converts recalcitrant pollutants into benign species instead of merely separating them into a hazardous brine stream, and
features very low capital and operating costs. HENCI reactors operate at ambient pressure and temperature, require no
chemicals, very little power, little maintenance, have an indefinite lifespan, and can be scaled, configured, and transported
easily for varying applications.