Abstract: A method of producing in a bioreactor a biogas rich in methane involves electrolyzing water in an aqueous medium at a voltage in a range of from 1.8 V to 12 V in the presence of electrochemically active anaerobic microorganisms that biocatalyze production of hydrogen gas, and, contacting a species of hydrogenotrophic methanogenic microorganisms with the hydrogen gas and carbon dioxide to produce methane. Volumetric power consumption is in a range of from 0.03 Wh/LR to 0.3 Wh/LR. Current density is 0.01 A/cmE2 or lower. The voltage is sufficient to electrolyze water without destroying microbial growth. Such a method results in improved electrolysis efficiency while avoiding the use of noble metal catalysts. Further, a combination of water electrolysis with anaerobic degradation of organic matter results in increased biogas quality and in increased biogas quantity and yield.

Abstract: The invention disclosure is a method of bioremediation of wastewater, particularly groundwater, by utilizing coupled anaerobic and aerobic biological treatment, more specifically, methanogenic (strictly anaerobic) and methanotrophic (strictly aerobic) microbial populations, in combination with a supply of in-situ generated water-dissolved oxygen and hydrogen. Water electrolysis is used to produce water-dissolved oxygen and hydrogen. The immediate advantage of using H2 from the electrolysis is to provide electron donors to methanogens to reductively dechlorinate the chloroaliphatics, and to reduce the water carbonates and generate methane which is used as energy and carbon source for the methanotrophic bacteria. Oxygen is used as electron acceptor by the aerobic bacteria, including the methanotrophs. The addition of an organic carbon source can be minimized or even eliminated, so as to diminish the competition between methanotrophic bacteria and heterotrophic bacteria for oxygen.

Abstract: A method and reactor for decontaminating underground aqueous plumes containing gasoline or other petroleum-derived hydrocarbons. The reactor contains a solid, non-sorptive packing, e.g a stainless steel foraminous packing which is characterized by a free space of at least 75%. The packing carries a microbial heterogeneous population derived from soil indigenous microbial community. The contaminated stream is passed through the bed in microaemphilic conditions. The performance of the process is better than that of a comparable process and apparatus using granulated peat moss.

Abstract: An integrated synchronous aerobic/anaerobic bioreactor is disclosed for treating waste liquids, such as pulp and paper waste water, and to methods of treating such waste liquid. The apparatus includes a bioreactor and an external aerator for injecting a controlled amount of an oxygen-containing gas into the waste liquid as it is cycled through the apparatus. An aerobic/anaerobic biofilm is provided in the reactor, having a decreasing gradient of oxygen concentration toward its core.