The invention relates to a method of treating water with activated sludge containing micro-organisms. The method comprises the steps of: preparing an environmentally adapted biomass mixture by adapting the activated sludge to a quantity of water having given characteristics in a single reactor under first levels of aeration, whereby the environmentally adapted biomass mixture acquires the capacity to cause concurrent reactions for BOD removal, nitrification and de-nitrification; and treating a p...

An improved method and apparatus for aeration of septic tanks and the like. Because of the interrelationship of the rotating impeller, an air plate and the horsepower of the unit in comparison with the volumetric size of the sludge tank, the unit disperses extremely small reduced pressure microbubbles adjacent the area of the impeller. These reduced pressure microbubbles are thereafter dispersed throughout the wastewater by Brownian movement without agitating the sludge. As a result, there is su...

Waste water containing organic materials is introduced into an aeration tank, and is subjected to aeration treatment in the presence of activated sludge, while supplying oxygen to the aeration tank. The organic materials contained in the waste water are oxidized by high-efficient activated sludge at a high oxygen transfer rate of 5 to 80 mmol O.sub.2 /l.multidot.hr to the aeration tank.

A method of treating organic waste water in an aeration tank is characterized by the fact that (1) the dissolved oxygen content in the aeration tank is adjusted to be within the range of 1.5-4.5 ppm; (2) the temperature of the waste water is controlled to be within the range of 15.degree.-40.degree. C. and the residence time of the waste water in the aeration tank is set at ten or more days if the ratio of the total carbon content to the nitrogen content of the organic materials contained in the...

A method and system for ballast water treatment are provided. Living organisms are added into a vessel's ballast water tank (e.g., via an existing vent) to consume (i) oxygen dissolved in ballast water contained in the ballast water tank, and (ii) food sources for selected organisms contained in the ballast water.

A system and method for mixing high viscous liquids with gas is provided. The disclosed embodiments include a reactor or mixing vessel having a draft tube disposed therein, a gas injection subsystem adapted to inject gas into the reactor or mixing vessel proximate the entrance of the draft tube. The embodiments also include an agitator disposed within the draft tube which makes the draft tube the primary site for the gas-liquid mixing. In particular, the agitator is adapted to create gas bubbles...

In treating water containing ammonium-nitrogen by a combination of a nitrification process and autotrophic denitrification bacteria, high efficiency denitrification treatment is achieved by providing adequate ratio between nitrite and ammonia in effluent of the nitrification process. Ammonium-nitrogen concentration of the raw water introduced to a nitrification reactor and the ammonium-nitrogen concentration of the nitrified liquid from the nitrification reactor is measured, and on the basis of ...

A system for treating wastewater includes a basin to contain wastewater, an aerator provided in the basin to mix the wastewater, and a cover system to cover a surface of the wastewater contained in the basin. The cover system includes a plurality of hollow bodies disposed on the surface of the wastewater. Each hollow body is adapted to float on the wastewater's surface, and has a contiguous outer surface and a sufficient mass so that 30 to 70 percent of the hollow body's outer surface is exposed...

Cationic polymers having a molecular weight greater than about 200,000 can be added to the activated sludge in an MBR for industrial wastewater treatment for reasons, which include: conditioning the activated sludge; improving flux through a membrane in the MBR; reducing fouling of the of the membrane in the MBR; and reducing foaming of the activated sludge in the MBR.

Methods and apparatus are provided for treating agricultural waste with an alkane substrate to stimulate bacterial digestion. The alkane treatment may also reduce odor of the agricultural waste material. The agricultural waste may include animal waste, vegetable material, leaf material, plant material, composting material or waste paper products. The alkane preferably includes butane, propane, methane and/or ethane, with butane being particularly preferred. Methods and apparatus are also provide...