Wetlands degraded

Stiuca, R., Staras, M., Tudor, M., 2002, The ecological restoration in the Danube Delta. An alternative for sustainable management of degraded wetlands, Proceedings of the 34th IAD Conference, p. 707 -720. 

Degraded wetlands. Wetlands in which the level of anthropogenic perturbance interferes with designated uses. 

Smith, S. M., S. Newman, P. B. Garrett, and J. A. Leeds. 2001. Differential effects of surface and peat fire on soil constituents in a degraded wetland of the Northern Florida Everglades. J. Environ. Qual. 30 1998-2005. 

Li J, Gu J-D (2006) Biodegradation of dimethyl terephthalate by Pasteurella mul-tocida Sa follows a novel biochemical pathway. Ecotoxicol 15 391-397 Li J, Gu J-D (2007) Complete degradation of dimethyl isophthalate requires the biochemical cooperation between Klebsiella oxytoca Sc and Methylobacte-rium mesophilium Sr isolated from wetland sediment. Sci Total Environ 380 181-187... 

Moreno-Mateos D, Pedrocchi C, Comih FA (2010) Effects of wetland construction on water quality in a semi-arid catchment degraded by intensive agricultural use. Ecol Eng 36 631-639... 

Radionuelides can be also used to study the accumulation and degradation of organic pollutants. In our experiments we have followed the uptake and degradation of labelled TNT by wetland plants (Nepovim et al., 2005), and showed that about 63% of the localized in the roots of Ph. australis was bound (Fig. 6) and the remainder was acetone-extractable. An HPLC analysis of the acetone extract failed to detect any TNT, showing that all TNT had been chemically transformed. Thus TNT was not adsorbed on the root surface. In similar experiments performed in wheat (Triticum aestivum). Sens et al. (1999) found that 57% of the taken up was bound... 

Land-use change in the coastal zone has accelerated the rate of pollutant loading for three reasons. First, removal of vegetation mobilizes materials, such as sediment. Second, the emplacement of impervious surfeces, such as roads and roofs, enhances pollutant transport as part of stormwater runoff Third, loss of natural habitats, such as wetlands, eliminates important ecosystem services, such as pollutant uptake and degradation. 

Constructed wetlands (CWs) can promote removal of PhCs through a number of different mechanisms, including photolysis, plant uptake, microbial degradation and sorption to the soil. The main benefits of horizontal and vertical subsurface flow systems are the existence of aerobic, anaerobic and anoxic redox conditions in proximity to plant rhizomes this provides an ideal environment for reducing... 

Ethyl chloroacetate, C4H7CIO2, is used as a solvent and in the synthesis of intermediate dye chemicals. The effluent from a dye synthesis plant is discharged into a wetland, with a pH of 7.3. At this pH, the alkaline hydrolysis rate constant is 1.56 M s . If the alkalinity of the wetland is close to constant, compared with the concentration change of the ethyl chloroacetate, at 0.002 M, what would be the first-order rate constant for ethyl chloroacetate degradation ... 

Degradation of ecosystems During the last decades, more than a half of the Earth s wetlands (from coastal marshes to intra-continental lowlands exposed to floods) has been lost due to various measures taken by humans, about half of virgin forests have been liquidated, 30% of the remaining forests have degraded. In 1999, the scale of the use of wood as a fuel and in industry had more than doubled as against 1950. 

While atrazine degradation to hydroxyatrazine was enhanced by the addition of ammonium sulfate in anaerobic wetland sediments (Chung et al., 1995), the addition of 2.0g/L of ammonium nitrate into aerobic wetland water sample reactors clearly inhibited atrazine degradation (Ro and Chung, 1995). In 15N tracer studies done with Pseudomonas strain ADP (which can use all five N atoms of atrazine as a sole N source), Bichat et al. (1997) indicated that while organic N sources had little effect on atrazine degradation, nitrate and ammonium delayed atrazine degradation. 

Oxygen deficiencies under field conditions have been reported to retard. v-triazine degradation. For example, Ro and Chung (1995) reported that in wetland sediments amended with nutrients, lOppm of atrazine reduced to less than lOppb within 3 weeks under aerobic conditions. Under anaerobic conditions, less than 50% degradation was reported in 38 weeks. However, Kruger et al. (1996) reported an opposite observation for a saturated soil where a 4-fold increase in degradation was reported. 

Lee, R.F., Ryan, C. (1979) Microbial degradation of organochlorine compounds in estuarine waters and sediments. In Proceedings of the Workshop of Microbial Degradation of Pollutants in Marine Environments. EPA-600/9-79-012. Washington D.C. Lee, S., Pardue, J.H., Moe, W.M., Valsaraj, K.T. (2003) Mineralization of desorption-resistant 1,4-dichlorobenzene in wetland soils. Environ. Toxicol. Chem. 22, 2312-2322. 

Moran, M. A., Benner, R. Hodson, R. E. (1989). Kinetics of microbial degradation of vascular plant material in two wetland ecosystems. Oecologia, 79, 158-67. 

Organic matter deposited in sedimentary or wetland habitats is composed of a complex mixture of biopolymers. Some of these compounds, such as proteins, carbohydrates, and lipids are easily degraded by microorganisms (i.e., labile), while other compounds, such as lignin and hemiceUulose, are resistant to decomposition (i.e., recalcitrant). Biopolymers are degraded in a multistep process. First, microorganisms simplify polymers to monomers such as amino acids, fatty acids, and monosaccharides (Figure 4). The monomers are further mineralized to CO2, or to a combination of CO2 and CH4. 

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