This application relates to a method of treating wastewater wherein an oxygen infusion system is used to supersaturate wastewater before aerobic biological processes, wherein oxygen is transferred to the wastewater free of oxygen bubbles and achieves a reduction in power demand for the aeration process of wastewater.

An example method for drying wastewater solids can include blending an anaerobically digested and de-watered biosolid cake with a previously biodried biosolid to form a mixed biomaterial pile and shaping the mixed biomaterial pile to form a static pile. The method also includes aerating the static pile by forced air ventilation throughout the mixed biomaterial pile to form a biodried material and dividing the biodried material into a recycle biosolid and a dried biomaterial product that is then suitable for disposal or use in agriculture or horticulture applications.

A device and method for shortcut nitrogen removal and nitrite-oxidizing bacteria activity inhibition are disclosed herein. An embodiment of the present invention provides a hollow fiber diffuser comprising: a plurality of hollow fibers on which bacteria can be attached and grow; and an inlet capable of supplying gas to one sides of the plurality of hollow fibers, wherein the gas includes oxygen and carbon dioxide, nitrite can be produced by the oxygen, and the concentration of oxygen in the gas is adjusted by the oxygen and the carbon dioxide.

Low strength wastewater such as municipal sewage is treated using an anaerobic digester. In some examples, a wastewater stream is separated into a solids rich portion and a solids lean portion. The solids lean portion is treated, for example to remove nitrogen. The solids rich portion is treated in an anaerobic digester, preferably with influent or recuperative thickening. In another example, the wastewater stream is fed to an anaerobic digester and solid-liquid separation stages downstream of the digester return active bacteria and undigested organics to the digester. Both cases may use a process train comprising treatment in an anoxic tank followed by a nitritation tank with a portion of the effluent from the nitritation tank recirculated to the anoxic tank to provide nitritation and denitritation.

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.

For bio-electrically generating electric power from organic ingredients of a waste water flowing in a flow direction, an anode is immersed in the waste water in a first spatial area, and oxygen is supplied to a cathode which is electrically connected to the anode and arranged in a second spatial area delimited from the first spatial area by means of a proton-permeable membrane. A voltage between the anode and the cathode is increased by a DC/DC converter located at the anode and the cathode, and a further voltage between a further anode in said or a further first spatial area and a further cathode in said or a further second spatial area is increased by a further DC/DC converter located at the further anode and the further cathode. A DC voltage link is charged with the DC/DC converter and the further DC/DC converter connected in parallel to the DC voltage link.

The present disclosure provides a water treatment module, a bioreactor comprising one or more of such modules and a receptive water treatment system. Also provided herein is a method making use of the above module, bioreactor and system. The water treatment module comprises (i) at least one elongated gas enclosure comprising a gas inlet and two vertical walls, at least one vertical wall comprising a water-impermeable and gas-permeable membrane having a water-facing side and a gas-facing side, the two vertical walls separating between water external to said enclosure and gas within said enclosure, the gas enclosure being in a rolled or folded configuration to thereby define a convoluted horizontal path and one or more water-treatment spaces formed between opposite water facing sides of the enclosure; and (ii) a diffuser arrangement comprising gas diffusers configured for introducing a stream of gas into the one or more water treatment spaces.

A method for wastewater treatment having a zero discharge of sludge, the method including: a) providing a membrane bioreactor system including a membrane separation system and a reaction vessel; and b) aerating the membrane separation system and the reaction vessel to control the dissolved oxygen concentration around the membrane separation system to be greater than 0 and smaller than 2 mg/L and the dissolved oxygen concentration in the reaction vessel excluding the membrane separation system to be greater than 0 and smaller than 1 mg/L. A wastewater treatment system having a zero discharge of sludge includes a membrane bioreactor system including: a reaction vessel, a membrane separation system, a water production system, and an aeration system.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

A device including a housing having a first side, a second side opposed to the first side, and a wall disposed between the first side and the second side. The wall forms at least a partially enclosed space inside the housing. The device also includes a membrane mounted to the wall inside the housing. The device also includes a drop pipe disposed inside the housing and through or around the membrane, the drop pipe having a proximal end and a distal end, the distal end being closer to the second side than the proximal end. The device also includes a diffuser connected to the distal end of the drop pipe.