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Cobalt

<0.0004

* Lstimates based on the judgment of the authors after considering information in Rets. 30. W. and 127.

* Lstimates based on the judgment of the authors after considering information in Rets. 30. W. and 127.

As mentioned in Section 3.2.1, the phosphorus requirement for normal microbial growth can be estimated as one-fifth of the nitrogen requirement on a mass basis. Consequently, about 0.017 mg of phosphorus will be required for each mg of heterotrophic or autotrophic biomass COD formed, and an equal amount will be released for each mg destroyed. If PAOs are in the system, the amount released by destruction of the biomass will be different and will depend on the amount of poly-P stored.

The provision of sufficient nutrients is essential if efficient wastewater treatment is to be achieved, because without them the microorganisms will not be able to perform their synthesis reactions. Although nitrogen and phosphorus are the nutrients needed in greatest quantity (macronutrients), many other elements are required by the microorganisms but are not normally included in the stoichiometric equation because of the complicating effect they would have. The need for them should not be ignored nor should their presence be taken for granted because severe problems can result if sufficient quantities are not available."'1:7 Table 3.3 lists the major micronutrients required for bacterial growth.87 There is little agreement in the literature concerning (heir quantities in biomass. One reason is that different bacteria have different requirements. Another is that bacteria tend to adsorb cations, thereby making it difficult to determine exactly the quantity actually incorporated into biomass. The values listed in Table 3.3 are the authors' best estimates of the quantities required based on examination of several sources.111 w

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