Optimum dechlorination for CHC contaminations
Fe0 is a water-insoluble metal. HMVT has developed a product in which tiny Fe0 particles are stored in ENNA droplets. We have named this product FENNA. This emulsion can be injected into the soil.
Contaminations with very high concentrations of pure product can be hard to remediate at times. Such high concentrations can be toxic for the bacteria. That is the reason why chemical oxidation is often applied first, in order to remove the highest peaks. HMVT is able to combine the biological degradation of chlorine contaminations with chemical reduction. Correctly putting together zero-valent iron and ENNA will create a mixture that allows us to remediate the highest concentrations and get the biology going all at once.
HMVT has been successfully applying ENNA since 2003. ENNA is short for Enhanced Natural Attenuation and provides sustainable biological degradation of chlorine contaminations. ENNA consists of emulsified soya bean oil that we inject into the soil as a milky substance. In various remediation projects we have seen a prolonged degradation of contaminants.
Pure product can be hard to clean up using ENNA as the contamination is still toxic for the bacteria. Prior to the injection of ENNA, chemical oxidation of the contamination is often applied to very high concentrations. This is an extra step in the remediation process and may result in extra costs. Oxidants have a negative effect on the biological degradation. Following the chemical oxidation, the circumstances must be returned to optimal levels for biological degradation.
Contamination may also be reduced rather than oxidised. In that case we are using zero-valent iron (Fe0). Zero-valent iron will reduce the contamination to harmless products, such as ethene.
Rather than in two steps (chemical oxidation and biological stimulation) we are able to complete the remediation in one single step. By doing so, the biological circumstances will remain very favourable and we are able to reduce the costs of remediation.