Evaluation of Bioremediation Treatments in a Shoreline-Simulating Microcosm

Abstract

A microcosm test was designed to study the efficiency of bioremediation treatments at oil contaminated shorelines. The biodegradation in the hermetically closed microcosm was monitored by measuring the total cumulative inorganic carbon evolved during the bioremediation process. The effects of three different additives, medium-release methylene urea (MU) + apatite, fast-release MU + superphosphate, and a biosorbent, on the biodegradation of weathered crude oil (North Sea Brent) were evaluated at +10°C. All the additives significantly increased mineralization. The total amount of inorganic carbon evolved during the 10-week study was measured in the microcosm treated with oil, and with oil and medium-release MU + apatite, fast-release MU + superphosphate, and biosorbent. The amounts were 40,670,490, and 580 mg, respectively. The respirometric measurements were supported by microbiological determinations, ATP content in the sand, number of heterotrophic bacteria, and amount of biomass-C determined by the substrate-induced respiration method. Nutrient analysis indicated that biodegradation was nitrogen limited. The microcosm test proved to be suitable for comparing the effectiveness of different treatments in enhancing the biodegradation of crude oil-contaminated shores.

Evaluating the biodegradation of aromatic hydrocarbons by monitoring of several functional genes

“…Several microbiological methods, such as the enumeration of microorganisms by cultivation on agars plates, determination of the ATP concentrations or general enzyme activities, have been applied for monitoring remediation processes (Piskonen et al 2002). Even though these methods can be used to monitor the overall microbial activity in the environment, they do not directly describe the enzymatic degradation of specific contaminants.…”

Site-Specific Limitations of Using Urea as a Nitrogen Source in Biodegradation of Petroleum Wastes in Soil

“…The closed system enables measurement of the total amount of CO 2 evolved during bioremediation. CO 2 produced from microbial respiration was used as an indirect measurement of hydrocarbon degradation (Brook et al, 2001;Piskonen et al, 2002). Ambient air supplied O 2 during the purging step in each sampling interval to maintain aerobic condition in the microcosms.…”

“…Aerobic bioremediation of petroleum-contaminated soils has been widely applied in the restoration of polluted sites (Atlas, 1991;Bento et al, 2005;Piskonen et al, 2002). Aerobic bacteria convert petroleum hydrocarbons into carbon dioxide, water, microbial biomass and metabolites.…”

Bioremediation of Petroleum Hydrocarbon Contaminated Sites

“…Fortuitous cometabolism is synonymous with the microbial metabolism of contaminants that are not growth substrates (Anderson, 1995). Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated sites (Atlas, 1991;Bento et al, 2005;Piskonen et al, 2002). It is known that hydrocarbons and weathered oils with carbon contents of about 20% degrade slowly (Flathman et al, 1993).…”