Biodegradation tests

Degradation tests are an effective way to determine whether the contaminants present at your site can be degraded biologically and what are the optimal conditions to achieve the fastest degradation rates. Tests can be conducted both on soil and groundwater, under aerobic or anoxic conditions.

The set-up of such tests allows to monitor the biological degradation of the compounds of interest under the natural conditions found at the site (Natural Attenuation – NA) and compare it with that of stimulating methods. It is possible to measure the impact that biostimulation (addition of nutrients) and bioaugmentation (addition of a competent culture) have on the biological degradation activity and thus on the efficiency of the restoration processes. Possible abiotic interactions and chemical oxidation are taken into account as well, to distinguish non-biological processes that might take place in the tests.

Nutrients such as nitrogen, phosphorus, potassium can be added as stimulants, as well as electron acceptors/donors such as oxygen, sugars, organic acids, depending on the contaminants to be degraded. An autochthonous culture can be used for bioaugmentation, which DND Biotech can prepare starting form a sample from the site of interest. Highly active inocula can also be tested, such as wastewater treatment plant effluent or sludge, soil or commercially available cultures, based on the requirements of the specific case.

The biodegradation progress can be followed by means of respirometric analysis, COD and nutrients measurements, quantification of the contaminants of interest throughout the duration of the test. Molecular techniques can also be applied to monitor changes in the microbial population along the degradation process, by means of a targeted approach (qPCR) or broad microbial community screening (metagenomics). These techniques can also later on be used as monitoring tools to assess the biodegradation activity in the full-field remediation.

The output of the degradation tests is a clear description of the biological degradation potential of the contaminants of interest under different process conditions. The results can be used to plan a full-scale remediation treatment, with the option of upscaling first to a piloting system such as ROBONOVA® or an in-situ technology such as bio-flushing.

Bio-flushing