A system and a method comprises a chamber configured to receive a flow of a wastewater mixture from an input. A first baffle wall forms a first channel within the chamber. The wastewater mixture flows from an input to an output of the first channel. A second baffle wall forms a second channel and a third channel within the chamber. The wastewater mixture flows from the output of the first channel to an input of the second channel to an output of the second channel to an input of the third channel to an output of the third channel. The output of the third channel is configured to direct the flow to an output from the first chamber.

Apparatus for introducing a gas into a main medium, comprising: a main conduit for guiding the main medium, a multitude of injection lines for guiding the gas, wherein each of the injection lines has a respective end section with a respective outlet opening situated within the main conduit, and wherein the end sections are oriented essentially parallel to each other and to the main conduit. With the apparatus a gas can be introduced in particular into waste water for obtaining a biologically activated sludge. Thereby, interaction between the gas and the waste water can be particularly pronounced due to a particularly large liquid-gas-interface caused by particularly extensive turbulences. Further, shear stress acting on particles in the activated sludge can be advantageously low, thus avoiding damage of the biological particles.

A hybrid membrane aerated biofilm reactor (MABR) and activated sludge (AS) system and process are described herein. At least a portion of the AS system includes aerobic mixed liquor, for example in an aerobic tank or zone downstream of a tank or zone containing membrane aerated biofilm modules. The flow of air to the membrane aerated biofilm is modulated considering the ammonia loading rate to the system or to the aerobic mixed liquor, for example according to a diurnal cycle. For example, air flow to the membrane supported biofilm can be below an average or initial air flow rate during a period of low ammonia loading. Air flow to the aerobic mixed liquor may remain essentially constants during the same period. Optionally, mixed liquor around the membrane aerated biofilm modules may be aerated during a period of high ammonia loading.

The invention comprises an activated sludge treatment system and process that aerates wastewater undergoing treatment using venturis.

An apparatus, method and system is provided for treating sewage sludge by dewatering the sewage sludge, heating the sewage sludge being treated to destroy pathogens, and then reducing volatile solids in the sewage sludge being treated through biochemical decomposition to produce a treated biosolids product that meets government regulations for pathogen reduction and vector attraction reduction.

Techniques for controlled aeration (140) of wastewater (190) include determining a first aeration intensity for a first aeration interval and a different second aeration intensity for a second aeration interval (225) based on a current energy price (215), a predicted energy price (221), and a regulatory surveillance period (201) during which a regulated critical parameter is monitored for regulatory compliance. Wastewater is aerated at the first aeration intensity for the first aeration interval; and at the second aeration intensity for the second aeration interval. The first aeration interval is short compared to the regulatory surveillance period, the second aeration interval is short compared to the regulatory surveillance period and does not overlap the first aeration interval, and the first aeration intensity is less than the second aeration intensity.

A water treatment system comprising a first reactor and a second reactor arranged to be placed in series in a body of water, the first and/or second reactor comprising at least one cell for housing biomedia. A mid-settling zone is provided between the first and second reactors for separating solids in the water. A method of treating water, the method comprising passing water to be treated through a first reactor and then a second reactor arranged in series in a body of water, the first and/or second reactors comprising at least one cell for housing biomedia, wherein the water is passed through a mid-settling zone between the first and second reactors before passing through the second reactor.

An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.

An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.

Disclosed is a split type continuous operation micro-grid dynamic membrane bioreactor. The split type continuous operation micro-grid dynamic membrane bioreactor comprises a biological treatment unit and a drum type dynamic membrane filtration unit, wherein the biological treatment unit comprises a microbiological treatment tank, and a water inlet pipe is arranged on the microbiological treatment tank; the drum type dynamic membrane filtration unit comprises a filter tank, and a drum micro-grid dynamic membrane mechanism is arranged in the filter tank; the drum micro-grid dynamic membrane mechanism comprises a filter drum, a backwashing device is arranged above the filter drum, and a sludge collecting bank is arranged in the filter drum; a water outlet is formed in the bottom of the filter tank; a mixed liquid pipe is arranged between the microbiological treatment tank and the filter drum; and a sludge discharge header pipe is arranged on the sludge collecting tank.