NOVELTY - The system comprises: (a) a carbon collection facility to collect carbon emissions, where the carbon emissions are produced by burning of high-carbon fuels or lime by a utility company; (b) a water distribution facility for providing water to consumers; (c) a wastewater treatment, facility to treat wastewater from the consumers and discharge treated wastewater; and (d) a lake as an aerial-bioreactor having a sufficient depth so that the surface layer remains alkaline to breed cyanobacteria, where the lake is fed the carbon emissions from the carbon collection facility.    USE - The system is useful for water-recycling and energy-recycling in an aqueous system, either in or near a city, and/or in a pre-existing or a new city park (claimed).    ADVANTAGE - The system is capable of rapidly water-recycling and energy-recycling in the aqueous system with increased efficiency and without evaporative water loss, and eco-friendly and economically allows de-nitrification process.    DETAILED DESCRIPTION - The system comprises: (a) a carbon collection facility to collect carbon emissions, where the carbon emissions are produced by burning of high-carbon fuels or lime by a utility company; (b) a water distribution facility for providing water to consumers; (c) a wastewater treatment, facility to treat wastewater from the consumers and discharge treated wastewater; (d) a lake as an aerial-bioreactor having a sufficient depth so that the surface layer remains alkaline to breed cyanobacteria, where the lake is fed the carbon emissions from the carbon collection facility; (e) a micro-floatation system located adjacent the lake to harvest plankton from the lake for manufacturing biofuels, where the plankton includes the cyanobacteria; (f) a natural stream or artificially dug canal located at a discharge site of the lake for discharging water from the lake, where the natural stream or artificially dug canal is a linear-bioreactor for biologic cleaning of the discharged water from the lake; (g) water-conditioners distributed throughout the natural stream or artificially dug canal to keep the water discharged from the lake slightly acidic; (h) hydrotransistors connected to the natural stream or artificially dug canal for filtration of surface water from the natural stream or artificially dug canal, where the hydrotransistors discharge the filtered surface water into a pre-existing or a new city park to achieve water-recycling; and (i) a Neo-Canerjing system for underground transport of water from the natural stream or artificially dug canal to the water distribution facility to avoid evaporative loss. The lake is connected to and fed treated wastewater from the wastewater treatment facility. The carbon dioxide from the carbon emissions is dissolved in the lake and nutrients from the treated wastewater promote the breeding of the cyanobacteria in the lake. The Neo-Canerjing system is built for transport in aquifers as compressional waves in water-saturated to avoid evaporative loss. The water discharged from the lake into the natural stream or artificially dug canal is kept at: a pH of 5.5-6.5 by the water-conditioners for biologic cleaning; and a pH of 7.5-8.5 by the water conditioners for the breeding of green algae and/or cyanobacteria.    DESCRIPTION OF DRAWING(S) - The diagram shows schematic view of a lake for energy recycling.