Beaches degradation

The floating debris and beach litter consists of many different materials that, tending to be non-degradable, endure in the marine environment for many years. 

Sheeks, C. J., Moshier, W. C., Ballinger, R. G., Latanison, R. M., Pelloux, R. M. N., Fatigue crack growth of Alloys X750 and 600 in simulated PWR and BWR environments , Proc. 1st Int. Conf. on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors, Myrtle Beach, USA, 22-25 Aug. 1983, NACR pp. 701-25 (1984)... 

Proposed aquaculture applications of degradable polymers include seaweed culture nets, fishing nets and lines, and temporary structures used for restoration of wet lands, beaches or other marsh areas [11-14], Weathering and hydrolysis are the most common degradation mechanisms encountered in aquatic applications. Continually submerged articles pose special challenges since temperatures are low and photodegradation and oxidation effects are limited. 

Petroleum hydrocarbons (oil and combustion by-products such as PAHs) Runoff and atmospheric deposition from land activities shipping and tanker operations accidental spills, coastal and offshore oil and gas production natural seepage Toxic effects including birth defects, cancer, and systemic poisoning. Tar balls degrade beach habitat. 

Piastics and other debris Runoff from urban areas and iandfiii dumping and ioss from cargo, miiitary, and cruise ships ioss of fishing nets Entangies marine iife or is ingested degrades beaches, wetiands, and nearshore habitats. 

When aquifers were amended with nitrate in order to stimulate biodegradation, the results were generally consistent with those obtained in laboratory investigations. In a field injection experiment at Seal Beach, California, Ball et al. (1994) demonstrated complete removal of w-xylene and the m-,/-xylene fraction decreased significantly in parallel bioreactor experiments. A Canadian study showed a decrease in m- and /-xylene of 14% and 15%, respectively, over aim flowpath in the Borden aquifer (Barbara et al., 1992). Very little degradation was observed beyond that point, presumably due to the availability of preferred electron donors in the landfill leachate impacted aquifer. 

Free sulfide (> 1 mM) and higher BTEX (> 300 /tM) concentrations inhibited the bioconversion. In another study with Seal Beach sediments (Haag et al., 1991), /(-xylene was degraded in sulfate-reducing columns at a similar rate (0.2 /tmol/kg/day). 

Ball, H. A. Reinhard, M. (1996). Monoaromatic hydrocarbon degradation under anaerobic conditions at Seal Beach, California Laboratory studies. Environmental Toxicology and Chemistry (in press). 

Stieglitz, L., Becker, R. 1982. Chemical and radiolytic solvent degradation in the PUREX process, in Nukleare Entsorgung Nuclear Fuel Cycle-, Baumgartner, F., Ebert, K., Gelfort, E., Lieser, K.H. Eds. Verlag-Chemie Weinheim, Deerfield Beach, EL, Basel, 333-350. 

M. Quintus et al., Chemical membrane degradation in automotive fuel cell -Mechanisms and mitigation, 2nd Annual International Symposium on Fuel Cell Durability Performance, Miami Beach, FL,7-8 Dec 2006... 

Long-term exposure of microbial populations to certain toxicants often is necessary for adaptation of enzymatic systems capable of degrading those toxicants. This was the case with the Exxon Valdez oil spill in Alaska in 1989. Natural microbial populations in Prince William Sound, Alaska, had developed enzyme systems that oxidize petroleum hydrocarbons because of long-term exposure to natural oil seeps and to hydrocarbons that leached from the pine forests in the area. Growth of these natural microbial populations was nutrient limited during the summer. Thus the application of nutrient formulations to the rocky beaches of Prince William Sound stimulated microbial growth and helped to degrade the spilled oil. 

Amzallag, C., Bernard, J.L., Slama, G., On Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, Proc. Int. Symp. Myrtle Beach, South CA, NACE, p. 727,1984. 

Laboratory investigations conducted shortly after the spill confirmed earlier studies that showed that N and P were limiting, and that almost all of the alkanes in the Alaskan oil and an appreciable amount of the PAHs had been metabolized in 6 weeks with the addition of inorganic salts or an oleophilic fertilizer containing N and P. Field tests confirmed the abundance of hydrocarbon-degrading bacteria. Specific N and P fertilizers were supplemented to the beaches because they would remain associated with the oil. The oleophilic fertilizer was a liquid containing urea in oleic acid as the N source and tri(aureth-4)-phosphate as the P source. Within 2 weeks, differences in the quantities of oil were visually evident between fertilizer-treated and untreated beaches, and subsequent quantitative measurements revealed that 60-70% of the oil had been degraded within 16 months. 

Ultimately, the cleanup crews collected 14% of the oil that was spilled while 13% sunk to the sea floor. A major portion of the remaining oil evaporated and another portion was naturally degraded over the years. About 2% ( 216 000gal) remained on the beaches. The most recent survey of lingering oil was conducted in the intertidal zone of Prince William Sound in the summer of 2001 by the... 

Oiled debris, beach material, and sorbents are sometimes disposed of at landfill sites. Legislation requires that this material not contain free oil that could migrate from the site and contaminate groundwater. Some governments have standard leach-ability test procedures that determine whether the material will release oil. Several stabilization processes have been developed to ensure that free oil does not contaminate soil or groundwater. One process uses quick lime (calcium oxide) to form a cement-like material, which can be used on roads as a dust-inhibitor. Another form of disposal is to process liquid oil in a bioreactor and thus attempt to break it down. This is usually not successful because of the many slowly degraded components in some oils. 

Tilling and aeration are used to break up surface layers or to expose subsurface oil. The exposed oil can then weather naturally and degrade, and will not leach into the water. Medium to heavy oils that form crusts are also broken down and asphalt pavement buried in the beach is exposed. This work is done with farm equipment, such as ploughs, discs, and cultivators and construction equipment such as bulldozers or graders with rippers. The technique is suitable for sand, sand-gravel, or pebble-cobble beaches. 

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