Anaerobic stages

This chapter focuses on the developmental regulation of the pyruvate dehydrogenase complex (PDC). The PDC plays diverse and pivotal roles in the entry of glycolytically generated carbon into the TCA cycle in aerobic stages and the metabolism of mitochondrially generated pyruvate in anaerobic stages (Fig. 14.1). 

Anaerobic stages of SBR studies have been shown efficient with color removal rates mostly higher than 70% [3, 18-20], Meanwhile, COD removal efficiency of anaerobic phase of SBR was found to depend on dyestuff type, amount of initial COD concentration, anaerobic cycle time, etc. Nevertheless, there are also reports about no efficient COD removal in anaerobic cycle of SBR [21, 22],... 

Previous studies suggested that enzymes responsible for the aromatic amine removal become more active when the color removal rates are high, which resulted in more aromatic amine production within the SBR. Beside this, adverse effect of anaerobic conditions on aerobic enzymes was also reported, and results indicated that their activities increased in aerobic stage and decreased in anaerobic stages due to the absence of dissolved oxygen [20, 69]. Viliesid and Lilly [70] found that the activity of catechol 1,2-dioxygenase is dependent on the dissolved oxygen... 

The kinetics of cell growth/death under free and/or immobilized states assume a relevant role in the assessment of the amount of biophase present in the reactor. Obviously, the kinetics depends strongly on the carbon/energy source available in wastewaters or purposely added. With the exception of consortia collected from anaerobic digesters, single strain cultures used in azo-dye conversion are characterized by hindered growth under anaerobic conditions [26, 29, 41], For these biosystems, the duration of the anaerobic stage must be carefully monitored to preserve cell viability. 

Model computations suggest that cyclic operation is able to regenerate during the aerobic stage the reducing potential for dye conversion during the anaerobic stage. 

Several studies have reported a positive relationship between the hydraulic retention time of the anaerobic stage and the color removal efficiency [95],... 

All of these processes incorporate aerobic and anaerobic stages, based on phosphorus uptake during the aerobic stage and its subsequent release during the anaerobic stage. Commercial systems can be... 

The net number of ATP molecules produced when one molecule of glucose passes through the anaerobic stage of respiration is ... 

In this chapter we recognize essentially two soil classes aerobic soils that are well drained and subjected to continued availability of oxygen, and peat that represents subaqueous deposits of vegetal matter subjected to an early oxidative stage of decomposition in upper layers but to an anaerobic stage of decomposition in the lower layers. Differences have been noted in the composition of humic substances in both of these soil classes (Kononova, 1966 Manskaya and Drozdova, 1968). Because of the differences in depositional environments, it is likely that different processes are operative in the formation of humin in these two classes of sediment. 

Stabilization reservoirs are a set of mutually connected reservoirs in which the process of treatment takes place gradually from the anaerobic stage in the first reservoir to the aerobic stage, for example involving fish breeding, in the last reservoir [1, 3, 5, 6]. 

As previously mentioned, packaging (either made with bioplastics or paper) and bioplastics that comply with EN 13432/14995 are expected to complete organic recycling in a full cycle that includes the anaerobic stage and the final aerobic stage (stabilisation of the digestate via postcomposting). 

The process of direct anaerobic-aerobic treatment resulting in humification of TNT and its congeners offers a convincing and simple concept (Fig. 18 process II) for the remediation of soil contaminated with TNT and congeneric compounds. This is evident by comparison with the alternative process I (Fig. 18), which requires the desorption of the contaminants by innocuous solvents such as methanol or ethanol. Desorption plus the separation of particles must precede the actual anaerobic process of polynitrotoluene reduction. Furthermore, the anaerobic stage requires a microbial system which degrades TAT and diaminotoluenes productively or at least to such an extent that subsequent aerobic treatment results in complete mineralization. 

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