A method enhancing biological digestion of wastewater sludge is provided. The method uses chlorine dioxide to accelerate and improve the efficiency of aerobic or anaerobic digestion.

A process approach allows economical self-sustained operation of single vessel biotreatment systems for municipal wastewater treatment. The daytime solar powered treatment process is changed during darkness periods to operate the biotreatment system without electric grid powering.

A wastewater treatment plant that employs an activated sludge process and a method of operating the same is described. Wastewater influent is provided to a bioreactor configured to perform activated sludge processing to develop mixed liquor suspended solids (MLSS). The MLSS is passed from the bioreactor to a hydrodynamic separator (HDS) system, where separation operations are performed on the MLSS. The separation operations generate a low concentration MLSS stream and a high concentration MLSS stream. The low concentration MLSS stream is passed from the hydrodynamic separator system via a first output to a clarifier, and the high concentration wastewater stream is passed via a second output back to the bioreactor. The clarifier performs clarification operations on the cleaned wastewater stream and then outputs an effluent flow.

A method for controlling the growth of blue algae in a basin relates to the field of the restoration and protection of the natural ecology on the earth's surface. An ecological water treatment system was constructed for the basin with microorganisms, plants, animals, fillers and the like as main elements by building a novel ecological slope protection at the land-lake ecozone along the banks of the basin and planting eucalyptus in the basin water and/or on the bank of the basin, thereby effectively realizing the efficient nitrogen and phosphorus removal from the basin, controlling the spread of blue algae and improving the environmental water quality.

A dual tank wastewater treatment system for performing an extended aeration process to provide a natural, biological breakdown of the organic matter in wastewater using, for example, but not limited to, a continuously operating air pump and diffuser bar system for aeration purposes and a flexible media filter. The air pump used is stronger than conventional air pumps and the diffuser bar is designed to provide more efficient oxygen transfer than conventional diffuser systems by mixing air against the system flow to provide better mixing and longer retention time in the aeration process. The flexible media filter provides a final filtration and polishing of the effluent before it passes through a flow equalization apparatus and exits the system.

A dual tank wastewater treatment system for performing an extended aeration process to provide a natural, biological breakdown of the organic matter in wastewater using, for example, but not limited to, a continuously operating air pump and diffuser bar system for aeration purposes and a flexible media filter. The air pump used is stronger than conventional air pumps and the diffuser bar is designed to provide more efficient oxygen transfer than conventional diffuser systems by mixing air against the system flow to provide better mixing and longer retention time in the aeration process. The flexible media filter provides a final filtration and polishing of the effluent before it passes through a flow equalization apparatus and exits the system.

A switching flow source system includes a switching flow apparatus and a source loop and a production loop that are in fluid communication with the switching flow apparatus. In a cooling mode a first heat exchanger, acting as a condenser, is fluidly connected to the source loop and a second heat exchanger, acting as an evaporator, is fluidly connected to the production loop. The switching flow source system can be switched to a heating mode by operating valves within the switching flow apparatus. In the heating mode the first heat exchanger is switched to being fluidly connected to the production loop while the second heat exchanger is switched to being fluidly connected to the source loop.

A method for treatment of mixed electroplating wastewater without a cyanide and a phosphorus-containing reductant without a cyanide and a phosphorus-containing reductant. A ferrous chloride solution is added into electroplating wastewater without a cyanide and a phosphorus-containing reductant. The pH of wastewater is adjusted to 10.5-12. Pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants are oxidized with sodium hypochlorite. Carboxyl-containing organic acid complexants are precipitated. Hexavalent chromium is reduced to trivalent chromium to form chromium hydroxide precipitate. Precipitate is removed by filtering and wastewater is adjusted to pH 4.5-5.5. Heavy metal ions are precipitated with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate. Precipitate and heavy metal capturing agents are adsorbed with activated carbon followed by removal of precipitate. Wastewater is adjusted to pH 6-8. Aliphatic polyamine complexants are destroyed using an available biological degradation technique to reduce chemical oxygen demand.

A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. A series of biological process zones lead to a secondary clarifier. Mixed liquor sludge, preferably from an aerobic zone, goes through a classifier or separator processing flow from the aerobic zone, to the secondary clarifier. In a sidestream process that can be included a portion of sludge preferably from an aerobic zone goes through a classifier or separator to selectively produce a granular-rich effluent, and the clarifier may also have a separator to further concentrate granular biomass, most of which is cycled back to an initial multi-stage anaerobic process zone. The anaerobic zone is structured and operated to encourage growth of granules in subsequent process zones.

A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. A series of biological process zones lead to a secondary clarifier. Mixed liquor sludge, preferably from an aerobic zone, goes through a classifier or separator processing flow from the aerobic zone, to the secondary clarifier. In a sidestream process that can be included a portion of sludge preferably from an aerobic zone goes through a classifier or separator to selectively produce a granular-rich effluent, and the clarifier may also have a separator to further concentrate granular biomass, most of which is cycled back to an initial multi-stage anaerobic process zone. The anaerobic zone is structured and operated to encourage growth of granules in subsequent process zones.