The present invention relates to a high-precision, high-efficiency recirculation system for preserving multiple-density biomass and attached biofilm in wastewater treatment bioreactors, which is characterized in that it consists of a bioreactor tank in which a central recirculation duct is centrally and vertically disposed, said duct comprising a diffuser cone at the bottom thereof, close to the bottom of a baffle of the bioreactor, and an upper guide cone at the upper end thereof, wherein the central recirculation duct is designed for an inductor/nozzle to be inserted there into up to the limit of the upper wall of the bioreactor baffle, said parts forming together a central assembly containing, in vertical attitude, a drive shaft which comprises, at the upper end thereof, above the inductor/nozzle, sealing means for hermetic sealing at the upper wall of the bioreactor baffle, wherein the upper end of the drive shaft is coupled to a low-revolution motor reducer for rotating the drive shaft, which comprises one or more axial-type impellers, and wherein the lower end of the drive shaft is coupled to a hyperbolic impeller/mixer close to the bottom of the bioreactor baffle.

The invention relates to a method for monitoring and controlling the operation of a liquid flow generator (1) configured for operation in a tank (18) housing in a liquid comprising solid matter. The flow generator (1) comprises a propeller (3) and a main body (7) having a drive unit (4), wherein a control unit (4) is operatively connected to the flow generator (1) in order to monitor and control the operation of the flow generator (1), the method comprises the steps of: a) driving the propeller (3) in a normal direction of rotation, wherein the liquid flow is directed from an upstream side of the propeller (3) towards a downstream side of the propeller (3), wherein the main body (7) is located at the upstream side of the propeller (3), b) performing a cleaning sequence in response to a main body cleaning signal, wherein the cleaning sequence comprises the steps of: i) stopping the propeller (3) from rotating in the normal direction of rotation, ii) driving the propeller (3) in a reverse direction of rotation, wherein the liquid flow is directed from the downstream side of the propeller (3) towards the upstream side of the propeller (3) and along the main body (7) in order to remove any solid matter accumulated on the main body (7), and iii) stopping the propeller (3) from rotating in the reverse direction of rotation, c) resume driving of the propeller (3) in the normal direction of rotation.

Systems and methods for enabling dynamic volumetric transitioning and segmentation of treatment conditions are disclosed. Such treatment conditions may include, by way of example, systems and methods for dynamically transitioning treatment environments within a reactor for activated sludge treatment processes. Such environments may include anaerobic, anoxic, fermentation, suboxic, and aerobic environments.

An apparatus for treating fluids having improved aeration efficiency and operational durability has an aerator, an impeller, and a liquid reservoir containing liquid to be treated. The aerator has: a motor rotating the impeller at a blade tip speed less than 1,100 inches/second; an air line having an outlet submerged in the liquid and an inlet adjacent to the motor; and a blower. The blower forces air through the air line to the air line outlet. The impeller two blades extending radially from the hub. Each blade has: a low drag, pressure equalized foil shape absent of rake; a leading edge extending from the hub tangentially; a 0.47-0.55 impeller EAR; 0.59-0.87 Pmean/D; progressive pitch distribution based on radius where from 50% R and out is constant and from 50% R to the hub is reduced; and 60-75 degree skew with a linear distribution from 50% radius to blade tip.

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.

The object is to provide an activated sludge treatment method whereby production of excess sludge is brought substantially to zero; and a method for upgrading existing waste water treatment equipment, employing this method. The method includes a step (1) in which sludge 1 produced in a bioreactor is supplied to a waste water aeration-conditioning tank for activated sludge treatment; a step (2) in which waste water into which the sludge 1 has been mixed is subjected to aeration-conditioning to bring the oxidation-reduction potential to a positive value, and the conditioning treated waste water 1 supplied to the bioreactor; a step (3) in which released water from the bioreactor is considered to release water.

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.

The present invention relates to a method and a device for controlling pollutants in basin water resources cycling utilization in agricultural activity areas. The method includes: providing an acidification tank, an aeration tank and a multi-media constructed wetland connected in sequence, which are 4˜10 m far from basin revetment, feeding basin water into the constructed wetland, adsorbing or degrading heavy metals and organic pollutants by the constructed wetland, and then transporting the treated basin water to the agricultural activity areas. The present invention effectively controls the content of heavy metals that will enter the agricultural activity areas, fundamentally reduces the content of heavy metals in the crops, promotes the growth of the crops, maintains sustainable and healthy development of agriculture, and therefore guarantees human health and safety.

A low energy apparatus to aerate liquid in a tank using pumped liquid flow over bubble aerators operating at low air pressure near the tank surface, with the flow of liquid and entrained bubbles then being directed through pipes at speeds sufficient to carry the bubbles to the bottom of the tank where the bubbles are released to rise to the top of the tank, infusing the liquid in the tank with air.

A wastewater purification apparatus includes an elongate tank, which has an inflow for feeding wastewater, a first vertical agitator with a first hyperboloid agitator body mounted on a vertical first agitator shaft and provided in a first treatment portion downstream of the inflow on the first narrow side, a second vertical agitator with a second hyperboloid agitator body mounted on a vertical second agitator shaft and provided in a second treatment portion downstream of the first vertical agitator, an aeration device with a fan for aerating wastewater received in the tank, a first drive device for rotating the first hyperboloid agitator body in a first rotation direction, a second drive device for rotating the second hyperboloid agitator body in a second rotation direction opposite the first rotation direction, and a decanter for discharging purified wastewater in a third treatment portion on a second narrow side opposite the first narrow side.