Aeration Technology
4Pages

Biological treatment systems require oxygen to function properly. The actual oxygen requirement is used to identify the oxygen demand for a system. Each plant is specific, but usual important parameters include temperature, dissolved oxygen level, plant elevation, and the design of aeration equipment. Either for industrial wastewater or for domestic sewage, the purification is carried out by biological aerobic activated sludge process. In aerobic processes the pollutants in the wastewater are removed by living microorganisms. While the presence of nitrogen is essential for the growth of the microorganisms that treat the waste stream, the presence of nitrogen compounds in the effluent stream can exert an oxygen demand and lower the dissolved oxygen content of the receiving water. It can also promote detrimental plant growth such as algae. In order to accomplish this efficiently, the aeration equipment must not only be capable of transferring oxygen, but also maintain sufficient uniform mixing of the micro-organisms with the oxygenated wastewater without breaking up the activated sludge floes. Therefore, the aeration equipment is the most important part of an activated sludge process. Asti m Vertical or Horizontal type Mechanical Surface Aerators as well as Jet Nozzle and Diffused Aeration Systems can be used for all types of aeration tanks with minimum overall costs.

VERTICAL SHAFT TURBINE AERATORS Astim Vertical Shaft Turbine Aerator is one of the most efficient mechanical surface aerators available. The aerator impeller consists of an inverted shallow cone with blades attached vertically to the underside of the cone. As the aerator rotates, the air is drawn into the liquid behind the blades and mixes with the wastewater in the region of the greatest turbulence. The front side of the blades disperse the oxygenated wastewater outwards over a large surface area in order to increase the oxygenation. This kind of action of the impeller creates an upward...

HORIZONTAL BRUSH Horizontal Brush Aerators are cost effective solutions for the oxidation ditches and carrousel systems, for which nitrification and de-nitrification is carried out in the same tank volume without any additional tank and pumping. They can also be used in compact plants in annular aeration tanks, surrounding the circular clarif iers. When using the Horizontal Brush Aerators with basins of about 3,5m depth the mixing performance is generally sufficient for the requirements of biological treatment. For large sized sewage treatment plants with deeper basins, submersible mixers...

Diffuser Type Aeration System during operation AERATION SYSTEMS Jet nozzle Aeration and Diffused Aeration systems are also in Astim design and manufacturing capability. The technology of Jet Nozzle Aeration involves combining two fluids streams in a common mixing chamber. Astim Jet Nozzle Aerator is designed to mix the water and the pressurized air. The efficient mixture is obtained while flowing through the special designed outlet nozzles. Astim also manufactures necessary pipe lines for Diffused Aeration systems. With Diffused Aeration, compressed air is released through the holes in...