| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
Experimental study was carried out to evaluate the applicability of anaerobic aerobic biological phosphorus removal process to various wastewaters, by making clear the mechanism of organic substrate metabolism in the course of phosphporus removal process. Results obtained can be summarized as follows.
1.When acetic acid is fed to the phosphorus accumulating sludge which is acclimatized to anaerobic aerobic process, acetate is uptaken to the sludge and poly hydroxy butyrate is formed, while carbohydrate in the sludge is consumed, under anaerobic conditions. The reducing power required for poly hydroxy butyrate synthesis may be supplied from the degradation of the previously accumulated carbohydrate.
2.When other acid, succinic, pyruvic, lactic or propionic acid, is anaerobically added to the sludge, the carbohydrate consumption is observed, as is the case with acetic acid. Carbohydrate in the sludge is expected to have a function of maintaining the redox balance in the cell under anaerobic conditions. This function may be essential in a particular metabolism required to promote phosphorus accumulation. Too reductive substances which can be conversted to reductive polymers without any reducting power, or substances which are too oxidative to be reduced by the reducing power supplied from the consumption of carbohydrate, may not be suitable substrates for the anaerobic aerobic phosphorus removal process.
3.Less than 1% of the total amount of ATP produced in the dissimilative metabolism of the sludge is utilized for polyphosphate synthesis. The energy for growth is not reduced very much by polyphosphate accumulation, which enables the sludge to maintain the yield value (mg VSS produced/mg TOC removed) at a required level.
It is recommended for future works to carry out an investigation on amino acid metabolism from a fundamental point of view, and to examine how we can apply the results obtained here to practical operation of the anaerobic aerobic process.
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