Organic matter biodegradation

The entry of strongly reduced landfill leachate into a pristine, often oxidized, aquifer, leads to the creation of very complex redox environments. Important processes include organic matter biodegradation, biotic and abiotic redox processes, dissolution/precipitation of minerals, complexa-tion, ion exchange, and sorption. The resulting... 

The general PLC approach described in the preceding text can be modified when the research aim is to investigate one selected compound (or a group of compounds), or in the case of some less common samples, such as highly biodegraded or hydro-thermal petroleum, tars, immature sedimentary organic matter, or even products of biomass combustion [70,86,87]. 

Seymour MP (1977) The biodegradation of particulate organic matter in saltwater media. Dissertation, Rice University... 

In a second calculation, we assume benzene not only biodegrades, but sorbs to organic matter in the aquifer... 

Fig. 21.3. Transport of benzene within an aerobic aquifer, as depicted in Figure 21.2, calculated assuming the species not only biodegrades, but sorbs to organic matter in the aquifer. Benzene in the simulation sorbs with a distribution coefficient of 0.16 x 10-3 mol (g sediment)-1, equivalent to a retardation factor R of 2. Fine lines show non-reactive case.

Fig. 21.4. Transport of benzene within an aerobic aquifer, modeled in two dimensions. Contaminated water containing 1 mg kg-1 benzene leaks into the aquifer over the course of two years, at the point indicated. As in the previous model (Fig. 21.3), the benzene is retarded by sorption to organic matter in the aquifer and attenuates due to sorption, biodegradation, and dispersive mixing. Plots were rendered using the matlab software.

Sanitary sewer network sanitary sewers—often identified as separate sewers — are developed to collect and transport wastewater from residential areas, commercial areas and industries. The wastewater transported in these sewers typically has a relatively high concentration of biodegradable organic matter and is therefore biologically active. Wastewater in these sewers is, from a process point of view, a mixture of biomass (especially heterotrophic bacteria) and substrate for this biomass. 

Wastewater characteristics play an important role in the nature of the sewer processes and to what extent they proceed. A number of parameters like temperature and pH and quality characteristics in terms of the biodegradability of the organic matter and the amount of active biomass available are crucial for the outcome of the transformations. 

These examples show that when excluding substances like heavy metals and organic micropollutants, the wastewater quality is closely related to the microbial biodegradability of organic matter. This characteristic feature is not... 

As seen from Table 3.5, organic matter constitutes an essential part of sewer sediments, however, generally with a low biodegradability. Class D (sewer biofilm) is included in the taxonomy (Section 3.2.7). Class A sewer sediment material is most commonly found in combined sewer networks. 

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