A sewage treatment apparatus comprises an external box body internally being provided with an anaerobic zone, an aerobic zone, a settling zone, a sewage reduction zone and an apparatus zone separated from each other, wherein the anaerobic zone, the aerobic zone, the settling zone and the sewage reduction zone communicate in sequence, the anaerobic zone communicates with a septic tank, the aerobic zone communicates with the anaerobic zone to reflux a part of mixed liquid to the anaerobic zone, the settling zone communicates with the anaerobic zone to reflux a part of active sludge to the anaerobic zone, and the sludge reduction zone communicates with the anaerobic zone or the septic tank; and the apparatus zone is internally provided with a detection unit for detecting various parameters during a sewage treatment process and a controller for controlling working states according to a detection result of the detection unit.

A method for treating wastewater by using a coagulant that aggregates a phosphorus-containing substance. The method includes executing a reaction phase having a biological treatment phase and a subsequent chemical treatment phase. The chemical treatment phase includes the first substep of mixing the wastewater while injecting a predetermined dose of the coagulant into the basin in order for the coagulant to contact and coagulate the phosphorus-containing substances. The injection of the dose of the binding compound into the basin is performed during a time period equal to or more than a time period required to accomplish two mixing turnovers of the wastewater and equal to or less than a time period required to accomplish seven mixing turnovers of the wastewater. The second substep includes mixing the wastewater in order to flocculate the coagulated substance.

A method for managing a wastewater treatment process. The method includes at least the steps of measuring an amount of at least one nitrogen-containing substance in the influent wastewater (CN, influent), and determining an amount of phosphorous to be removed from the influent wastewater (CP, influent) based on the measured amount of at least one nitrogen-containing substance in the influent wastewater (CN, influent).

A method of controlling cooling water treatment may involve measuring operating data of one or more downstream heat exchangers that receive cooling water from the cooling tower. For example, the inlet and outlet temperatures of both the hot and cold streams of a downstream heat exchanger may be measured. Data from the streams passing through the heat exchanger may be used to determine a heat transfer efficiency for the heat exchanger. The heat transfer efficiency can be trended over a period of time and changes in the trend detected to identify cooling waterfouling issues. Multiple potential causes of the perceived fouling issues can be evaluated to determine a predicted cause. A chemical additive selected to reduce, eliminate, or otherwise control the cooling water fouling can be controlled based on the predicted cause of the fouling.

Disclosed herein are methods and systems for removing carbon dioxide (CO.sub.2) from water and quantifying the carbon so removed, thus facilitating valuation of that carbon for schemes (e.g., Kyoto agreement) that attach financial rewards for capture, sequestration or removal of carbon or CO.sub.2.

We describe a method of determining a food-to-biomass ratio in an aqueous fluid the method comprising: providing an aqueous fluid comprising viable biomass and food for said biomass, and wherein there is insufficient available food to sustain all said viable biomass; using a sensor (for example a respirometer or a sensor for sensing an amount of ammonia, ammonium, nitrates or nitrites) to determine an amount of food in said aqueous fluid available to said biomass; determining a measure of viable biomass in said aqueous fluid by measuring polarisability of viable biomass cells in an AC electric field; and determining a food-to-biomass ratio from said amount of food and said measure of viable biomass.

A biofilm process is disclosed for treating wastewater containing readily biodegradable dissolved organic matter GP (measured as chemical oxygen demand or COD) and producing surplus biomass from the biofilm process that includes an enhanced polyhydroxyalkanoate (PHA) content. The process comprises directing a wastewater influent containing the readily biodegradable COD (RBCOD) into a biofilm unit process. The PHA content of surplus biomass is enhanced by controlling for a decreased biofilm process specific organic loading rate in combination with controlling phosphorus loading rates relative to the process RBCOD loading rates: (1) controlling the wastewater influent phosphorus loading rate to the biofilm unit process includes maintaining an average RBCOD/P ratio of the influent that is between 200 and 800 g/g; (2) decreasing the process specific organic loading rate includes producing a biofilm unit process effluent having readily separable mixed liquor volatile suspended solids (RS-MLVSS); and (3) separating a portion of the RS-MLVSS from the biofilm unit process effluent and recycling at least a portion of the separated RS-MLVSS back to the biofilm unit process. The combination of the RBCOD/P control and specific loading rate control maintains, on average, the surplus biomass with a PHA content that is greater than 30% gPHA/g VSS.

Systems and method for treating wastewater including a vessel having an inlet and an outlet, a pump in fluid communication with the outlet of the vessel, the pump configured to pump wastewater out of the vessel, a separator in fluid communication with the pump, the separator configured to separate grit from the wastewater, the separator having a first outlet for discharging a grit stream and a second outlet for discharging a wastewater stream, a grit washing system in fluid communication with a source of washing fluid and the first outlet of the separator, the grit washing system configured to wash and dewater grit from the grit stream, the grit washing system having an outlet for discharging a wash wastewater stream, and a return conduit configured to recycle the wastewater stream discharged from the separator to one of the inlet of the vessel and an inlet to the pump.

There are provided processes for treating wastewater. The processes can comprise treating a mixture comprising the wastewater and an activated sludge, in a single reactor, with an electric current having a density of less than about 55 A/m.sup.2, by means of at least one anode and at least one cathode that define therebetween an electrical zone for treating the mixture; exposing the mixture to an intermittent ON/OFF electrical exposure mode to the electric current in which an OFF period of time is about 1 to about 10 times longer than an ON period of time; and maintaining an adequate oxidation-reduction potential in the single reactor. Such processes allow for substantial removal of carbon, nitrogen and phosphorus from the wastewater in the single reactor of various forms and for obtaining another mixture comprising a treated wastewater and solids.

A process for the biological treatment of wastewater in which the performance of a conventional activated sludge system is improved by adding an aerobic granular biomass system in a hybrid parallel process configuration. Waste biomass and suspended material from the aerobic granular biomass system is introduced into the conventional activated sludge system for this purpose. In the hybrid process configuration the advantages of both systems are combined to produce new advantages, while drawbacks of the individual systems are reduced to great extent.