The present disclosure relates to a bacterium-alga coupled sewage treatment device based on energy recycling and a use method thereof. The device comprises a pretreatment device, a photobioreactor, an alga separation apparatus, a continuous flow bioreactor and a secondary sedimentation tank which are sequentially connected in order, the pretreatment device being connected to a municipal sewage inlet pipe, the photobioreactor being connected to a carbon dioxide gas charging device through a gas filling pipeline, one part of a sludge thickening tank being connected to the secondary sedimentation tank, the other part thereof being connected to remaining sludge of the pretreatment device, carbon dioxide generated from the sludge which flows through the thickening tank and is thermally-hydrolyzed and anaerobically-acidified being connected to the photobioreactor through a gas inlet pipeline, and the alga separation apparatus being further connected to a filter press. The present disclosure has the advantages of a rational structural design, reliable and stable operation, a low operation and maintenance cost and high automaticity and intelligence, and being suitable for the use and transformation requirements of a wide range of sewage treatment plants, etc.

A water treatment system includes a plurality of tanks; a plurality of blow systems connected to tanks respectively; a blower unit configured to supply air to tanks through the air blow systems; and a control device configured to: calculate a pressure loss in each of the air blow systems; and control supply of water to be treated to each of the tanks, according to the calculated pressure losses.

This disclosure includes systems and methods for optimizing aeration in wastewater treatment. The techniques described herein include receiving data for a wastewater treatment plant, the data being descriptive of water quality over a period of time. The techniques further include developing a predictive model for future water quality based on the received data. The techniques also include determining, based on the predictive model, a plurality of DO setpoints and airflow rates for the wastewater treatment plant. The techniques further include controlling an aeration system for the wastewater treatment plant using the plurality of DO setpoints and the airflow rates.

An advanced nitrogen removal method using partial nitrification-denitrification coupled two-stage autotrophic denitrification. Sewage is introduced into a first pool for partial nitrification-denitrification treatment, and then introduced into a first regulating reservoir. Dissolved oxygen content in the first pool is kept at 0.4-0.6 mg/L. Water is discharged when a molar ratio of nitrite nitrogen to ammonia nitrogen in the first regulating reservoir is 1.0-1.3:1. Effluent in the regulating reservoir is introduced into a second pool for anaerobic ammonia oxidation treatment, and then introduced into a second regulating reservoir. In the second pool, pH is 7.0-7.4, a temperature is 22-28° C. Effluent in the second regulating reservoir and sulfides are introduced into a third pool for denitrification treatment. Water is discharged. In the third pool, pH is 7.5-8.0, a temperature is 28-32° C., a mass ratio of sulfur to nitrogen is 1.9-2.0:1.

A rural landscape-type nitrogen and phosphorus ecological interception ditch system and a farmland drainage nitrogen and phosphorus interception method using the system are provided. The system includes a sediment buffer zone, an ecological ditch unit, an interception-conversion pool and a field ridge hedge fence; the sediment buffer zone, the ecological ditch unit, and the interception-conversion pool are sequentially arranged in a continuous ditch along a direction of a water flow; and the field ridge hedge fence is arranged on field ridges on one side or both sides of the ditch. The present disclosure can, on the basis of not affecting normal production functions of a farmland, further exert an ecological role of the farmland, and use the farmland as an assimilation sink for environmental nitrogen and phosphorus, so as to optimize drainage water quality and improve a farmland ecological environment.

A septic system is provided that includes a septic tank having a plurality of compartments with a tank inlet in a first compartment. First and second vaults are positioned in a second compartment. The first vault receives fluid from the first compartment at a level near a fluid surface in the tank. A first flow inducer receives fluid from the first vault at a level near a bottom of the first vault, and releases fluid into the second compartment at a level near the fluid surface. The second vault receives fluid from the second compartment at a level near a bottom of the second vault and discharge fluid at a level near the fluid surface. Third and fourth vaults and a second flow inducer are positioned in a third compartment, the third vault receiving fluid from the second vault, and the fourth vault discharging fluid to a tank outlet.

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 method for obtaining grey water excreta includes reducing ammonia content of the liquid fraction in a first porous medium in which the ammonia content is decomposed, and reducing the byproducts in a second batch of similar porous medium. The byproduct may be decomposed into nitrogen. A system for obtaining grey water from a liquid fraction of human or animal excreta includes: a first bio-filter for reducing an ammonia content of the liquid fraction, the first bio-filter including a first vessel and a first porous medium in which the ammonia content is at least in part decomposed into at least one byproduct; and a second bio-filter for reducing the at least one byproduct, the second bio-filter including a second vessel and a second batch of similar porous medium within the second vessel and in which the at least one byproduct is at least in part decomposed.

A method for treating wastewater or sludge comprises the steps of adding the wastewater or sludge to a reactor and mixing the wastewater or sludge with a stream to thereby decrease a ratio of alkalinity to ammonium in the reactor, the reactor containing ammonium oxidising bacteria that oxidise ammonium to produce nitrite and decrease pH.

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.