Marine Biodegradation Results

Marine Biodegradation Results for PHA, PLA, and Control Test Samples after 180 Days... 

The most immediate advantage of making biodegradable plastics is to address the problems of litter and marine pollution resulting from plastics disposal, which are difficult to solve any other way. 

The environmental behaviour of LAS, as one of the most widely-used xenobiotic organic compounds, has aroused considerable interest and study. As a result, it has been determined that, under certain conditions, LAS compounds are completely biodegradable however, in the marine environment their degradation is known to be slower. The presence of metabolites of the anionic LAS surfactants, the long and short chain SPC derivatives, in the aqueous environment is well known, and as such these degradation intermediates needed to be monitored (and tested for their toxic effects). 

The presence of suspended solid materials increases the extent of LAS biodegradation [13,28], but the rate of the process remains invariable. The influence of the particulate material is due specifically to the increased density of the microbiota associated with sediments. However, suspended solids may also reduce the bioavailability of IAS as a result of its sorption onto preferential sites (e.g. clays, humic acids), although this is a secondary effect due to the reversibility of the sorption process. Salinity does not affect IAS degradation directly, but could also reduce LAS bioavailability by reducing the solubility of this molecule [5], Another relevant factor to be taken into account is that biodegradation processes in the marine environment could be limited by the concentration of nutrients, especially of phosphorus and nitrogen [34],... 

The removal of LAS from the marine medium is, in general, a slow, but efficient process. co-Oxidation is the first step in the LAS biodegradation process, resulting in SPCs. (3-Oxidation is the main route responsible for... 

The degradation of sulfur heterocycles in Prudhoe Bay crude oil by aerobic enrichment cultures of marine and soil microorganisms was studies by Fedorak and Westlake (22,22). Figure 4 shows typical results obtained when the aromatic fraction of the oil was analyzed by capillary GC with a sulfur-specific detector. The mixed microbial populations in these enrichments were able to degrade the n-alkanes, pristane, phytane and a number of polycyclic aromatics in this oil (21, 22). There were some similarities between the biodegradability of the sulfur heterocycles in Figure 4 and that of the aromatic hydrocarbons reported by Fedorak and Westlake (21,22). For example, although cultures without N and P addition were able to remove a number of the sulfur heterocycles from the oil, the addition... 

As a result of the current demand for biodegradable and environmentally friendly sources of raw materials, these uses have a place in the marketing of marine oils well into the twenty-first century and will command premium prices if special niches for the oil can be developed. The competitiveness of the oleochemicals... 

Bis(2-chloroethyl)ether s former production and use in the textile industry and as solvent in natural and synthetic resins may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 1.55 mm Hg at 25°C indicates that bis(2-chloroethyl)ether will exist solely as vapor in the ambient atmosphere. Vapor-phase bis(2-chloroethyl)ether will be degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals the half-life for this reaction in air is estimated to be 5 days. If released into soil, bis(2-chloroethyl) ether has a high mobility. Many ethers are known to be resistant to biodegradation. Volatilization from moist soil surfaces is an important fate process. If released into water, bis(2-chloroethyl)ether is not adsorbed by suspended solids and sediment in water. Volatilization from water surfaces is an important fate process. The volatilization half-life from a model river and a model lake is estimated as approximately 40 h and 16 days. Bis(2-chloroethyl) ether is a marine pollutant and its release to the sea is prohibited by the International Convention since 1973. ... 

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