Anaerobic advantages

One advantage of anaerobic reactions is that the methane produced can be a useful source of energy. This can be fed to steam boilers or burnt in a heat engine to produce power. 

In all types of biological processes, excess sludge is produced which must be disposed of. The treatment and disposal of sludge are major problems which can be costly to deal with. Anaerobic processes have the advantage here, since they produce considerably less sludge than aerobic processes (on the order of 5 percent of aerobic processes for the same throughput). 

Regenerated cellulose does, however, have the advantage that it biodegrades well aerobically in composting (rather more slowly anaerobically). 

The primary advantage of aerobic digestion is that it produces a biologically stable end product suitable for subsequent treatment in a variety of processes. Volatile solids reductions similar to anaerobic digestion are possible. Some parameters affecting the aerobic digestion process are ... 

Recently, anaerobic filter process has been widely used for the treatment of various waste-waters because of several advantages over aerobic process such as lower nutrient requirement, less surplus sludge production, and energy recovery via methane production [1]. Although many types of anaerobic filter process have already been successfully commercialized, the details of their complicated process dynamics are still challenging issues to be clarified for their stable operations. 

A subtle control of the particle morphology and size can also be brought about using Fievet s Polyol process for catalyst preparation. The main advantage here is the easy access to nanoparticulate metals at any normally equipped laboratory bench without the restrictions imposed by anaerobic working conditions [224]. It is clear... 

Successful field-scale applications of engineered bioremediation systems have been limited to the aerobic pathway, as opposed to the anaerobic pathway. The advantages of the aerobic pathway include the following ... 

The inability to produce high-quality effluents is one significant disadvantage. Another disadvantage is that anaerobic processes must be maintained at temperatures between 35 and 40°C to get the best performance. If low-temperature waste heat is available from the production process, then this is not a problem. One advantage of anaerobic reactions is that the methane produced can be a useful source of energy. This can be fed to steam boilers or burnt in a heat engine to produce power. 

Looking at Table 7.8 it is readily seen that in terms of fitness eukaryotes and prokaryotes each have advantages and disadvantages so that the best solution for total optimal energy capture is coexistence assisted by cooperation not competition. If life could have started from a situation where there had been an ample supply of sufficiently reduced basic small molecule materials and energy and no reduction but only molecular combination was required, it may well have been that anaerobic prokaryotes would have remained exclusively successful. They are still in abundance on the Earth. There would have been no need to reject oxidised materials, and increase in the number of compartments would have had little advantage since the observed chemically necessary syntheses (see Chapter 4) are simply... 

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