The use of aeration in the treatment of wastewater has increased considerably since the early 1950's. Aeration plants have been used extensively in the treatment of wastewater in small communities, shopping centers, schools and subdivisions. This invention relates to wastewater treatment methods to produce Class A Biosolids. This invention relates to aeration systems for wastewater treatment plants and the like and more particularly to an improvement in fine bubble gas diffusers and gas diffuser systems. Diffusers 108 are constructed in accordance with the above description, except filtered blow-down assemblies 110 are located off center, and gas inlet pipes 112 enter through the bottom of diffusers 108. While the embodiment described in connection with the previous figures is preferred, the embodiment shown in FIG. 6 allows adaptation of my improved diffusers in systems having floor mounted piping and support systems similar to the one illustrated in FIG. 6. The operation of the alternate embodiment is substantially the same as that described above. Drop pipe 22 of assembly 14 allows liquid to escape from the diffuser 10 but does not allow gas to escape at normal operating pressure. 14 allows the use of media which can operate at relatively high pressures within the vessel 24, such that media 13 generates evenly distributed bubbles and air is distributed throughout a multi-diffuser system.

20 is preferred to avoid impact of entering air directly on diffuser media 13 when entrance is from the bottom or avoid impact of entering air on the filter 16 when entrance is from the top. 14 is located off center when the diffuser air supply pipe 26 enters from the bottom. However, when the air supply was shut off for any reason, a back flow of sludge would get into the diffusers and cause plugging. In most cases plugging will occur with continued used and power outages. The most significant advantage of a sand filter seems to be a simple system that you can use in plenty of other cases to produce substantial yields. Some of that gets sprinkled on lawns and a bit washes cars and pets, but overall we use that water either for cleaning ourselves and our dishes and clothes, in which cases it ends up going down the drain, or for drinking, in which cases it ends up going down the toilet. 14 and filter 16 enables the use of media 13 having properties which allow the use of relatively large areas of porous fine bubble-generating diffuser media. As more water passes through the iron filter, the oxygen in the unit is used up, and the media gets loaded with iron.

These systems can filter the water at a faster rate of flow than the coated types of media. 13 can be any material capable of generating small bubbles and maintaining an internal pressure of approximately 8 to 10 inches water column at operating air flow rates. By reading the details and watching a few minutes step- by- step guideline video you can easily install the filter by yourself. The general statement, with few exceptions, can be made that large bubble diffusers get the job done. All types of fine bubble diffusers provide a greater air economy when compared to most large bubble air diffusers. However, at today's energy prices (cost per KWH), large bubble diffusers suffer from increased operational costs compared to other alternatives. Cost is much less of an issue because the opportunity cost of not doing something is far greater than costs of software development itself. This device was improved upon and led to the development of more efficient large bubble diffusers. The development of fine bubble diffusers began in the early 1900's with the objective of producing diffusers with improved air economy.

Fine bubble diffusers emit air bubbles ranging from 2 to 5 mm in diameter. 12 is a 24-inch diameter flat sheet of 1/8-inch sintered plastic having an average pore size of 20 microns. These diffusers emit air bubbles in excess of 5 mm is diameter. Fine bubble diffusers come in the form of plates, domes or tubes and are constructed of ceramic, synthetic fabric or plastic material. 2. Ceramic plates and tubes. Reed Bed Sewage Treatment System is an extremely eco friendly system where sewage is allowed into a constructed water body where certain kinds of aquatic plants are planted which absorb atmospheric oxyen and let this out through their roots thereby providing the oxygen to feed the microbes which will clean up the sewage. A schematic diagram of the pilot scaled filter system is shown in Figure 1. The feed water of the filters used in the present study was groundwater obtained from a water source well in Xi’an, China.