The Microbiology of Anaerobic Digesters
110 TOXICITY Sulfide in an anaerobic digester may be in the soluble or insoluble form. In the insoluble form such as lead sulfid ...
HEAVY METALS 111 Although some heavy metals (cobalt, molybdenum, and nickel) at trace concen- trations serve as additives or act ...
112 TOXICITY Heavy metal ions that are very toxic to methane-forming bacteria at relatively low concentrations are copper, nicke ...
FEEDBACK INHIBITION 113 CYANIDE Cyanide (–CN) and cyanide-containing compounds (cyano-compounds) are com- monly found in industr ...
114 TOXICITY Feedback inhibition may be overcome by using a two-phase anaerobic digester system (Figure 17.5). This system separ ...
RECALCITRANT COMPOUNDS 115 Because the chemical composition and structure of several long-chain fatty acids are similar to those ...
...
18 Mixing 117 Anaerobic digester content should be mixed. Mixing enhances the digestion process by distributing bacteria, substr ...
118 MIXING TABLE 18.1 Advantages of Mixing Digester Content Eliminating or reducing scum buildup Eliminating thermal stratificat ...
Sludge recirculation can be used for mixing digester content, but this method generally is not used. When the method is used, sl ...
...
PART IV PROCESS CONTROL AND TROUBLESHOOTING ...
...
19 Upsets and Unstable Digesters 123 Under steady-state conditions the anaerobic digester operates without difficulty. Adequate ...
increase in effluent volatile solids also will take place if toxicity to both groups of bacteria occurs. However, this increase ...
pumping schedules, especially in warm wastewater temperatures. Concerns that are related to the production of malodors during wa ...
...
20 Foam and Scum Production and Accumulation 127 The production and accumulation of foam is a common problem experienced by many ...
128 FOAM AND SCUM PRODUCTION AND ACCUMULATION Vigorous mixing or excessively high mixing rates and fine bubble gas mixing enhanc ...
CARBON DIOXIDE 129 alkalinity also may serve as an indicator of other operational factors that contribute to foam production. Hi ...
«
1
2
3
4
5
6
7
8
9
10
»
Free download pdf