The results of a recent bench-scale test confirmed the effectiveness of a special blend of CL Solutions’ microbes formulated for PAH bioremediation. The test results showed that after two weeks, the total concentration of 15 PAH compounds decreased by 85% from a total of 358 mg/kg to 50.9 mg/kg. Benzo(A)pyrene is often a most difficult PAH to remove. The test showed that the custom blend reduced the benzo(A)pyrene concentration from 24.5 mg/kg to 3.68 mg/kg. Tests will continue to determine whether even greater effectiveness can be achieved over 30 days.
Recent data from field applications of Petrox bioremediation show degradation rates of 100 to 500 micrograms per liter (ug/ml) per day. These degradation rates are for total petroleum hydrocarbons or total BTEX, depending on the site monitoring requirements.
Achieving high degradation rates requires high initial concentrations. Initial concentrations of 1,000 to 10,000 ug/l were used to develop these degradation rates.
At lower concentrations, the degradation rates depend on effective distribution of microbes for cell to contaminant contact. Secondly, desorption of petroleum constituents from submerged soil may cause rebound and suggest lower degradation rates. For these reasons we cannot calculate a degradation rate for petroleum at low concentrations.
Using a special microbial blend, Delta Environmental has been successfully bioremediating high concentrations of heavy oil in soil around pipelines and oil production equipment. At a typical site, Delta reduced the concentration of petroleum C34 to >C50 from 130,000 mg/Kg to less than 10,900 in 30 days. That is a removal rate of 3,970 mg/Kg/day. This approach not only benefits the environment and meets green cleanup standards, but saves money and equipment downtime for the facility.
Sulfolane is an emerging contaminant of concern for potential environmental impact to ground water in Alberta. CL Solutions recently completed laboratory bench-scale testing that showed the Petrox organisms can efficiently degrade sulfolane. Under laboratory conditions Petrox organisms metabolized sulfolane at a minimum rate of 33 ug/L/day. Further lab tests are under way and field scale implementation may proceed in the Summer of 2017.
Petrox microbes were added to excavated petroleum-contaminated soil to accelerate the degradation of DRO and ERO total petroleum hydrocarbons. Petrox was added by spraying the surface of the soil with a hydrated Petrox solution. The microbes were mixed into the soil using a tractor-mounted disc tiller.
After approximately 60 days, soil samples were taken for testing. The soils showed 90% to 99% petroleum removal. The following chart shows the range of DRO and ERO concentrations before and after Petrox treatment.