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.

A method and apparatus for conditioning the settled solids in the bottom of a wastewater filtration tank to reduce the acidification of the sludge and prevent the excessive growth of undesirable biological growth.

The invention relates to the design of an enclosure for a membrane aeration module, which incorporates a reversible, low-pressure, air-lift pump to encourage a vertical water flow through and between the membranes in the module. These enclosed membrane modules are suitable for use in membrane aerated biofilm reactors, which are used to treat water or wastewater.

A solar-powered aeration device for sludge turnover and planting includes a grow bed fixed on a floating body and floats on water. A bottom of the floating body is fixedly connected with an inner pipe; an outer pipe is sleeved outside the inner pipe. The outer pipe is nested in an air chamber; a bottom of the air chamber communicates and is fixedly connected with a water inlet pipe; the water inlet pipe laterally communicates with a suction tube. An aeration ring is fixedly arranged at a bottom of the outer pipe, and the aeration tube has an air outlet pipe in communication with the outside. A movable foot is rotationally provided at a tail end of the suction tube, and the movable foot adapts to surface fluctuations to swing in a range limited by an angle limiter.

This document describes a gas streaming device for use between an injection port and a mixing chamber within an airlift pump, and an airlift pump with the gas streaming device. The gas streaming device includes a planar plate with multiple holes extending therethrough, where the holes are dimensioned to direct the gas into multiple micro-streams for streaming air from the injection port into the mixing chamber. An airlift pump in combination with such a gas streaming device is useful for removing anomalously high concentrations of dissolved gas in a liquid. The increased efficiency for this invention may also enable this type of pump to be economic in other applications where it is desirable to lift a liquid or induce flow.

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.

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.

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.

A process for aerobic treatment of wastewater is provided, which process comprises: (a) supplying a liquid influent comprising wastewater to a reactor containing granular biomass; (b) subjecting the reaction mixture to aerobic conditions comprising a concentration of dissolved oxygen from 0.1 mg/L to 4.0 mg/L, and a hydraulic retention time from 0.5 to 72 hours; (c) separating the reaction mixture into granular biomass and treated wastewater; and (d) recycling separated granular biomass to the reaction mixture. A bioreactor for the process is also disclosed, comprising a reaction vessel provided with an aeration means, a solids separation device with an inlet in the lower part of the reaction vessel having an outlet line for solids arranged to transport separated solids to a riser driven by airlift action and arranged to transport the solids to the upper part of the reaction chamber.

An organic wastewater treatment device includes a biological treatment tank in which biological treatment units are connected in series along a flow of organic wastewater. Each biological treatment unit has a pair of an anoxic tank disposed on an upstream side, and an aerobic tank disposed on a downstream side in which a membrane separation device is immersed in activated sludge. The activated sludge returns from a most downstream-side aerobic tank to a most upstream-side anoxic tank through a sludge return path. Whether to stop an operating membrane separation device and whether to start a stopped membrane separation device are determined for each biological treatment unit based on at least one of an inflow amount of the organic wastewater, a tank water level, a transmembrane pressure difference of each membrane separation device, a T-N concentration of the treated water, and an NH3-N concentration of the treated water as an index.