A method of generating electricity in a body of water includes providing a colony of sulfur-reducing bacteria, a colony of sulfur-oxidizing bacteria, and a colony of denitrifying bacteria submerged in the body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid, which can react with manganese to produce hydrogen gas. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides in the body of water to nitrogen gas, which can be bubbled through a portion of water from the body of water to remove dissolved oxygen gas. The hydrogen gas and oxygen gas can be combined in a fuel cell generator to generate electricity.

In a cooperative optimal control system, firstly, two-level models are established to capture the dynamic features of different time-scale performance indices. Secondly, a data-driven assisted model based cooperative optimization algorithm is developed to optimize the two-level models, so that the optimal set-points of dissolved oxygen and nitrate nitrogen can be acquired. Thirdly, a predictive control strategy is designed to trace the obtained optimal set-points of dissolved oxygen and nitrate nitrogen. This proposed cooperative optimal control system can effectively deal with the difficulties of formulating the dynamic features and acquiring the optimal set-points.

In a cooperative optimal control system, firstly, two-level models are established to capture the dynamic features of different time-scale performance indices. Secondly, a data-driven assisted model based cooperative optimization algorithm is developed to optimize the two-level models, so that the optimal set-points of dissolved oxygen and nitrate nitrogen can be acquired. Thirdly, a predictive control strategy is designed to trace the obtained optimal set-points of dissolved oxygen and nitrate nitrogen. This proposed cooperative optimal control system can effectively deal with the difficulties of formulating the dynamic features and acquiring the optimal set-points.

Disclosed herein is a method for remediating sewage that contains persistent contaminants. The method comprises ozofractionating the sewage under conditions whereby a foam fractionate comprising persistent contaminants is produced and separated from an ozofractionated wastewater, quiescing the ozofractionated wastewater, whereby a residual ozone content of the ozofractionated wastewater is reduced, and contacting the quiesced ozofractionated wastewater with a microorganism population under conditions effective to biologically remediate the ozofractionated wastewater.

A system and method of injecting a gas enriched and/or emulsified first liquid into a second liquid is disclosed. The injection can cause generation of a high density of bubbles having a mean diameter of a selected size. The mean diameter of the bubbles can be selected and varied based on the characteristics of the injection system.

A system and method of injecting a gas enriched and/or emulsified first liquid into a second liquid is disclosed. The injection can cause generation of a high density of bubbles having a mean diameter of a selected size. The mean diameter of the bubbles can be selected and varied based on the characteristics of the injection system.

A wastewater treatment device has: an ozone generator which supplies ozone; a mixer which mixes ozone supplied from the ozone generator with wastewater and supplies ozone mixed wastewater; an ozone oxidation unit which progresses ozone oxidation in the ozone mixed wastewater while passing the ozone mixed wastewater therethrough and discharges wastewater in which the ozone has been consumed; a biological treatment unit which performs biological treatment on the wastewater discharged from the ozone oxidation unit using microorganisms; and an adjusting device which adjusts the amount of ozone to be mixed with the wastewater by the mixer so that ozone in an amount that inhibits the microorganisms of the biological treatment unit does not remain in the wastewater discharged from the ozone oxidation unit.

A wastewater treatment device has: an ozone generator which supplies ozone; a mixer which mixes ozone supplied from the ozone generator with wastewater and supplies ozone mixed wastewater; an ozone oxidation unit which progresses ozone oxidation in the ozone mixed wastewater while passing the ozone mixed wastewater therethrough and discharges wastewater in which the ozone has been consumed; a biological treatment unit which performs biological treatment on the wastewater discharged from the ozone oxidation unit using microorganisms; and an adjusting device which adjusts the amount of ozone to be mixed with the wastewater by the mixer so that ozone in an amount that inhibits the microorganisms of the biological treatment unit does not remain in the wastewater discharged from the ozone oxidation unit.

The present disclosure provides systems and processes for recycling biogenic CO.sub.2. A system includes an aquacultural reservoir (102) configured to contain water (108) and aquatic animals (110) that live therein; a separation stage (104) in fluid communication with the aquacultural reservoir, wherein the separation stage is configured to receive water from the aquacultural reservoir and separate biogenic CO.sub.2 gas (114) from the water; and a fermentation tank (106) in gas communication with the separation stage, wherein the fermentation tank is configured to receive and convert the biogenic CO.sub.2 into biomass (126) by fermentation. The produced biomass can be used to cultivate the aquatic animals in the aquacultural reservoir.

The present disclosure provides systems and processes for recycling biogenic CO.sub.2. A system includes an aquacultural reservoir (102) configured to contain water (108) and aquatic animals (110) that live therein; a separation stage (104) in fluid communication with the aquacultural reservoir, wherein the separation stage is configured to receive water from the aquacultural reservoir and separate biogenic CO.sub.2 gas (114) from the water; and a fermentation tank (106) in gas communication with the separation stage, wherein the fermentation tank is configured to receive and convert the biogenic CO.sub.2 into biomass (126) by fermentation. The produced biomass can be used to cultivate the aquatic animals in the aquacultural reservoir.