One of Verhoeve’s specialties is conducting biological anaerobic degradation of chlorinated solvents. We have used this technique for 10 years, especially at former laundries. After the potential removal of the source zone, the lower concentrations and the plume zone can be perfectly remediated through a biological phase. Injecting carbon sources and nutrients can stimulate anaerobic decomposition. A carbon source must be well dispersed into the soil and it is best if it has a long time to work (slow release) resulting in the release of hydrogen (H). In cooperation with Deltares in the Netherlands, Verhoeve developed a carbon source that holds both features: VCS ® (Verhoeve Carbon Source).
Verhoeve owns several self designed and built facilities for groundwater extraction and carbon source and (cultured) bacteria addition. The process is continuously monitored by online measuring of pH, oxygen and redox values. In a relatively short period of time a contaminated surface can be fully equipped with a carbon source and, if required, biomass to accelerate anaerobic biodegradation.
To quickly switch to a biological treatment after chemical oxidation through Perozone ®, anaerobic bacteria can be added using the already existing chemical filters.
- Direct injection of carbon sources into filters
- Recycling of groundwater adding carbon sources and bacteria
Verhoeve Environment & Water frequently applies aerobic degradation at sites contaminated with fuel components or aerobically degradable chlorinated solvents such as vinyl chloride. The biological processes improve when oxygen or nutrients are added. The oxygen can be administered as compressed air or in its pure form, induced by generators. In addition, salts or special components can issue oxygen via direct injection or mixtures.
Oxygen is important yet ultimately it is about biological activity and therefore the presence and increase of bacteria. In our testing area we can determine this as well as predict degradation capacities and the need for additional nutrients.
- Air sparging through micro porous filters with compressed air or oxygen
- Direct injection of oxygen components (shock load)
- Aerobic treatment of wastewater in halophyte with ‘oxygen tubes’
- Recycling of groundwater with oxygen or nutrients