Processes and system are provided for digesting biosolids in a multistage digestion system. The processes and system are well suited for producing Class A biosolids and biogas containing a high content of methane. Methods and systems are also provided for recovery of phosphorus from wastewater and biosolids.

The invention relates to a method and an assembly for recovering magnesium ammonium phosphate from slurry that is supplied to a reaction container (10) in which an aerobic milieu is present and in which the slurry is guided in a circuit with the aid of ventilation. Cationic magnesium, such as magnesium chloride, is added to the slurry, and magnesium ammonium phosphate crystals which are precipitated from the slurry are removed via a removal device (30) provided in the base region of the reaction container. Substances which contain magnesium ammonium phosphate crystals collected in the removal device (30) are loosened and/or rinsed.

A process monitoring device includes a data collector, a statistic calculator and a comprehensive statistic calculator. The data collector acquires two or more variables indicating a state of a monitored target. The statistic calculator output each of the statistics that select two from the acquired variables. The comprehensive statistic calculator output a comprehensive statistic indicating a state of the monitored target based on a statistic output by the statistic calculator.

The present application discloses a class of aerobic efficient-phosphorus-removal bacteria that enable to biologically self-assemble and synthesize nanoparticles while wastewater treatment, including Shewanella sp. CF8-6, Psychrobacter aquimaris X3-1403, and Erythrobacter citreus X3-1411. The strains in the present application have a high adaptability, which may grow, remove nutrients including phosphorus and synthesize nanoparticles within a broad range of pH values, salinity, temperatures, and nutrition concentrations of wastewater. Particularly, the outstanding performance of phosphorous removal at high-salinity has a high significance in wastewater treatment from seawater utilization such as seawater toilet-flushing to solve the fresh water resource deficiency. Self-flocculation and self-assembly are the important properties of the strains to form biofilms and synthesize calcium phosphate nanoparticles at low-concentrations, while decomposing contaminants in the wastewater. The application provides an environmental-friendly nanoparticle synthesis method with low-cost and without chemical additives, which realizes the efficient treatment of wastewater and high value phosphorous resources recovery.

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.

The present invention relates to a coagulant composition comprising a coagulant and a carbon source compound, wherein the coagulant is selected from the group iron and aluminium salts, or any combination thereof. The carbon source includes methanol, ethanol or glycol. The present invention further relates to a method of treating wastewater, e.g. containing nitrogen and/or phosphate, including providing the coagulant composition to wastewater before, during and/or after a biological treatment step, and the use of the coagulant composition in wastewater treatment.

A method for operating a wastewater treatment plant for treating effluent, in particular for recovering phosphorus from the effluent to be treated and for respecting a phosphorus discharge limit in the effluent. The method includes the steps of carrying out an enhanced biological phosphorus removal process on at least a part of the effluent to be treated in a water line of the plant, deriving a sludge from the effluent that is being treated in the water line of the plant, subjecting the derived sludge to a step of acidification giving an acidified sludge, and carrying out a step of a first recovery of a phosphorus product in a liquid phase of the acidified sludge or directly in the acidified sludge giving a re-usable product and a phosphorus depleted acidified sludge.

A method of treating wastewater is disclosed in which a flow equalization reactor is provided that includes at least one wastewater treatment zone. A first wastewater treatment process is performed in the at least one wastewater treatment zone, which can be switched to a second wastewater treatment process. The flow equalization reactor is designed with a variable liquid depth and volume that can operated as a mixed wastewater zone, an anaerobic reactor zone, an anoxic reactor zone or an aerobic reactor zone. The equalization reactor provides sufficient variable liquid depth and volume above a minimum liquid depth and residual volume to provide the necessary hydraulic flow equalization or surge volume to achieve a relatively constant effluent pumping rate or feed forward flow rate over 24 hours per day, seven days per week into the downstream biological treatment processes, clarifiers, filters, or disinfection units, etc.

Described herein are methods and devices for treating water, wastewater, and organic wastes. The methods and devices are mixed by using hydraulic surge mixers. This surge mixer is driven by gas and can provide occasional surges of water using large bubbles which are able to move great volume of liquid while minimizing dissolved oxygen transfer to the surrounding liquid. Use of the devices and processes herein provides a simple, eloquent approach to water and wastewater treatment with less operation and maintenance costs than conventional devices and/or processes. The same surge lifting device can also be installed in other reactors to mix the tank content and enhance reaction with reduced energy use and maintenance needs.