Abstract: Bioventing systems create a bacterial treatment zone at a contaminated site by supplying a hydrocarbon food source to the treatment zone, and recirculating the hydrocarbon to the treatment zone. The bioventing systems may inject, circulate, extract and reinject hydrocarbons such as butane or other alkanes to the subsurface at a contaminated site to create a bacterial treatment zone. Contaminated vapors extracted from the soil and/or groundwater may be reintroduced into the site. Hydrocarbons that are not consumed by the bacteria in the treatment zone may be extracted and recovered for recirculation into the treatment zone.

Abstract: Methods and apparatus are provided for treating agricultural waste with an alkane substrate to stimulate bacterial digestion. The alkane treatment may also reduce odor of the agricultural waste material. The agricultural waste may include animal waste, vegetable material, leaf material, plant material, composting material or waste paper products. The alkane preferably includes butane, propane, methane and/or ethane, with butane being particularly preferred. Methods and apparatus are also provided for recovering plant growth-enhancing material from the treated agricultural waste and for treating soil with alkane-utilizing bacteria and/or an alkane substrate in combination with a carrier material to increase seed, bulb, plant and crop growth.

Abstract: A method of enhancing plant growth comprises the step of introducing an alkane into a location adjacent to a plant. The alkane can be introduced intermittently, and can be combined with another gas and/or nutrients. The alkane preferably comprises a butane substrate. The butane substrate can stimulate the growth of butane-utilizing bacteria, such as Aeromonas caviae, Stenotrophomonas maltophilia, Micrococcus varians, Aureobacterium esteroaromaticum, Aureobacterium barkeri, Rhodococcus fascians, Nocardia paradoxus, Comamonas acidovorans and Pseudomonas aeruginosa. The alkane can increase the amount of heterotrophic bacteria in the location adjacent to the plant, and thereby accelerate a heterotrophic nitrification process. The butane substrate can also stimulate the growth of butane-utilizing fungi. The method can also enhance the growth protists and/or prokaryotes. A system for enhancing plant growth in accordance with the method is also disclosed.