摘要:
A method of biologically treating wastewater and removing contaminants from the wastewater is disclosed. In the course of treating the wastewater, biomass is produced. In addition to removing contaminants from the wastewater, the process or method of the present invention entails enhancing the PHA accumulation potential of the biomass. Disclosed are a number of processes that are employed in a biological wastewater treatment system for enhancing PHA accumulation potential. For example, enhanced PHA accumulation potential is realized by exposing the biomass to feast and famine conditions and, after exposing the biomass to famine conditions, stimulating the biomass into a period of feast by exposing the biomass to feast conditions for a selected period of time by applying an average peak stimulating RBCOD feeding rate of greater than 5 mg-COD\L\MIN in combination with an average peak specific RBCOD feeding rate greater than 0.5 mg-COD\g-VSS\MIN. In another example, the PHA accumulation potential of the biomass is enhanced by subjecting the biomass to feast conditions that cause the biomass to reach a peak respiration rate that is at least 40% of the extant maximum respiration rate of the biomass. Other processes are discussed that can contribute to enhancing PHA accumulation potential of biomass.
摘要:
A method or process is provided for treating wastewater and producing a polyhydroxyalkanote (PHA)-storing biomass. The method or process entails biologically treating wastewater and in one process a filamentous biomass is selected and caused to proliferate so as to dominate an activated sludge. The filamentous biomass is utilized to treat the wastewater and to remove contaminants therefrom. As a part of this process, there is provided an enhancement for PHA production potential in the said biomass. This entails enhancing the PHA production potential of the filamentous biomass by subjecting the biomass to alternating feast and famine conditions where under feast conditions more biodegradable organic substrate is available to the filamentous biomass than under famine conditions. In another process, wastewater is treated with an activated sludge. The wastewater is treated in a main stream and as a part of the process, the activated sludge and biomass contained therein is concentrated and directed to a side stream. In the side stream, at least a portion of the enhancement for PHA production potential in the biomass from the process is carried out. In one particular process, the activated sludge and the biomass contained therein is concentrated by a separator and the concentrated biomass is directed to a side stream and subjected to famine conditions.
摘要:
A method or process for producing polyhydroxyalkanoates (PHAs) in biomass. The process entails feeding an organic carbon containing substrate to biomass enriched in PHA accumulating bacteria. Particularly the process entails intermittently supplying the substrate to the biomass at least three separate times over a selected period. The object of the process is to produce PHA having a relatively high molecular weight, at least 400,000 g/mole. By controlling the frequency at which the substrate is supplied to the biomass and by feeding a sufficient amount of the substrate to the biomass, the method or process produces the PHA having the relatively high molecular weight.
摘要:
A method or process for producing polyhydroxyalkanoates (PHAs) in biomass. The process entails feeding an organic carbon containing substrate to biomass enriched in PHA accumulating bacteria. Particularly the process entails intermittently supplying the substrate to the biomass at least three separate times over a selected period. The object of the process is to produce PHA having a relatively high molecular weight, at least 400,000 g/mole. By controlling the frequency at which the substrate is supplied to the biomass and by feeding a sufficient amount of the substrate to the biomass, the method or process produces the PHA having the relatively high molecular weight.