Dear Chinqyeh,

The following is the preparation procedure for activated sludge'e culture medium:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a method of preparing a microbial culture for wastewater treatment comprising the steps of supplying an aerated material derived from an aeration tank to a bioreactor and cultivating a microorganism existing in the aerated material by adding a culture medium to the bioreactor.

Preferably, the culture medium comprises 0.05-3 wt % peptone, 0.01-2 wt % yeast extract, 0-2 wt % glucose, 0-2 wt % KH2PO4, 0-1 wt % K2HPO4, 0.001-0.1 wt % magnesium sulfate, and 0.0001-0.5 wt % iron chloride on the basis of the aerated material. Content of every component is a solid content on the basis of the weight of aerated material. The culture medium need not have water because of the aerated material is an aqueous solution. If the content of every component deviates from the range, pH of the medium, number and species of a microorganism can be change.

As shown in FIG. 1, the present invention provides a wastewater treatment plant comprising: a primary settling tank (11) for removing a solid substance and a suspended solid substance from a raw sewage; an aeration tank (13) for decomposing an organic material in a raw sewage by aerating the raw sewage with a microorganism, the aeration tank (13) being linked to the primary settling tank (11); a bioreactor (17) linked to the aeration tank (13), the bioreactor (17) being supplied with an aerated material from the aeration tank (13) and a culture medium, preparing a microbial culture by mixing the aerated material with the culture medium, and supplying the microbial culture to the aeration tank (13); and a secondary settling tank (15) for settling a sludge floc supplied from the aeration tank (13), the settling tank (15) being linked to the aeration tank (13).

Preferably, the culture medium comprises 0.05-3 wt % peptone, 0.01-2 wt % yeast extract, 0-2 wt % glucose, 0-2 wt % KH2PO4, 0-1 wt % K2HPO4, 0.001-0.1 wt % magnesium sulfate, and 0.0001-0.5 wt % iron chloride on the basis of the aerated material.

A microorganism having a relatively high activation to wastewater exists in the aeration tank of the wastewater treatment plant. In the present invention, a microorganism separated from the aeration tank is cultivated in a liquid medium and the microorganism is supplied to the aeration tank, thereby increasing a concentration of the microorganism having a high activation to wastewater in the aeration tank.

A state of microorganism is dependent on COD of the aeration tank. A microorganism separated from an aerated material including many organic materials, has a relatively high activation to wastewater. Therefore, it is preferable that the aerated material derived from the aeration tank is used as a seed to obtain a high activation microbial culture.

A composition of the medium can be variable according to species of microorganism. For example, the medium comprising 0.05-3 wt % peptone, 0.01-2 wt % yeast extract, 0-2 wt % glucose, 0-2 wt % KH2PO4, 0-1 wt % K2HPO4, 0.001-0.1 wt % magnesium sulfate, and 0.0001-0.5 wt % iron chloride may be used. When the medium has an excessive quantity of glucose as a carbon source, mold can be cultivated predominantly in the aeration tank. When the composition of the medium is not appropriate, number or type of the microorganism can be change. The medium may comprise a small quantity of mineral except for the carbon source and a buffer solution. The medium is favorable to separate an effective microorganism from the aeration tank compared to a nutrient medium because the composition of the medium is similar to the composition of a minimal medium.

http://www.google.com/patents/US6383379

Regarding the other questions:

1-As you can see, the above mentioned procedure contains both K2HPO4 and KH2PO4. Both salts are good source of phosphorus; the only differences between them is the pKa and MW which do not have any effect on the medium.

2-MgSO4 and MgSO4.7H2O can be used as a source of Mg+2; the difference between them is the MW which does not have any effect on the medium.

3-FeCl3 and FeCl3. 6H2O are used as a source of Fe+3; similarly to the compounds mentioned in point 2, there is no difference between these two compounds except of their MW which does not have any effect on the medium.

4-Glucose solution should be filtered, however, there is no need for sterilization.

Hoping this will be helpful,

Rafik

Thank you very much for your explanation. May I know why glucose solution need to be undergo filtration?

It is just to remove any undissolved particles that might contaminate the medium. Generally, the filtration step is done for all solutions (FeCl3, MgSO4, glucose, potassium dihydrogen phosphate and potassium hydrogen phosphate).

Rafik