Sediment hydrocarbon types

Blaylock JW, Bean RM, Wildung RE (1974) Determination of extractable organic material and analysis of hydrocarbon types in lake and coastal sediments. Special publication no. 409. National Bureau of Standards, Washington, DC, p 217... 

Effects of Hydrocarbon Types on Sediment Formation With 2,5-Dimethylpyrrole (DMP) W ... 

Migration describes the process which has transported the generated hydrocarbons into a porous type of sediment, the reservoir rock. Only if the reservoir is deformed in a favourable shape or if it is laterally grading into an impermeable formation does a trap for the migrating hydrocarbons exist. 

The environmental occurrence of polycyclic aromatic hydrocarbons is mainly associated with dispersion of oil products and with various types of combustion. For these chemicals a kind of pre-industrial background exists, due to forest fires or to domestic wood burning. The sediments of the deepest strata were certainly deposited in the nineteenth century, when no significant industrial activities had been initiated. The ratio between PAH concentrations found in the sediments dated to this century, and the deepest ones, vary from 1.7 to 30, increasing from the beginning of the... 

Aliphatic hydrocarbons, triazine, substituted urea type and phenoxyacetic acid types of herbicides, Fluazifop and Fluazifop-butyl herbicides, ethylene diamine tetracetic acid salts in soil, aliphatic and polyaromatic hydrocarbons, phthalate esters, various organosulphur compounds, triazine herbicides, optical whiteners, mixtures of organic compounds and organotin compounds in non-saline sediments, aromatic hydrocarbons, humic and fulvic acids and mixtures of organic compounds in saline sediments and non-ionic surfactants and cobalamin in sludges. 

This technique has been applied to the determination of chlorinated insecticides, carbamate insecticides and substituted urea type herbicides in soil and chloroaliphatic hydrocarbons in non-saline sediments. Separation is usually achieved on thin layers of silica gel or alumina. 

The polyaromatic hydrocarbons in the soil sample were quantitated by using an external standard of anthracene. The results reportedly for a polluted soil and sediment sample indicate that this flash evaporation-pyrolysis technique combined with gas chromatography-mass spectrometry is a valuable tool for rapidly screening polluted samples for virtually all types of anthropogenic contaminants except for heavy metals. 

In some cases, when petroleum and/or petroleum products are released to the environment, a free phase is formed and sample(s) of the hydrocarbon material can be collected directly for characterization. The ability to analyze free product greatly aids the determination of product type and potential source. The samples may be diluted prior to analysis EPA SW-846 3580 (waste dilution) gives some guidelines for proper dilution techniques. However, caution is advised since as part of the initial sample collection procedure, water and sediment may be included in the sample inadvertently. Several protocols involved in initial isolation and cleanup of the sample must be recognized. In fact, considerable importance attaches to the presence of water or sediment in crude oil (ASTM D1796, D4007), for they lead to difficulties in other analyses. 

Electrokinetic treatment can be used to remediate soils, sludges, and sediments contaminated with heavy metals and organic hydrocarbons. Electrokinetic treatment works well on clay-type soils with low hydraulic permeability, which are difficult to treat using other in sitn technologies. Electrokinetic permeabilities for aqueous systems in clays have been demonstrated to be up to 1000 times greater than normal hydraulic permeabilities, and some heavy metals have exhibited removal efficiencies of up to 100%. 

Various workers have assembled relatively complete assessments of the annual input of the major biological nutrients (C, N, P), certain heavy metals (Mn, Cd, Pb, Cu), and petroleum hydrocarbons to Narragansett Bay. Other studies have developed inventories of the amounts of these materials in the sediments of the Bay. We have brought these data together with information on sediment accumulation rates in the Bay to determine the degree to which this one estuary serves as a sink for different types of materials in their passage between land and the coastal ocean. 

Karickhoff (1980) and Karickhoff et al. (1979) have studied sorption and desorption kinetics of hydrophobic pollutants on sediments. Sorption kinetics of pyrene, phenanthrene, and naphthalene on sediments showed an initial rapid increase in sorption with time (5-15 min) followed by a slow approach to equilibrium (Fig. 6.7). This same type of behavior was observed for pesticide sorption on soils and soil constituents and suggests rapid sorption on readily available sites followed by tortuous diffusion-controlled reactions. Karickhoff et al. (1979) modeled sorption of the hydrophobic aromatic hydrocarbons on the sediments using a two-stage kinetic process. The chemicals were fractionated into a labile state (equilibrium occurring in 1 h) and a nonlabile state. 

Results of the EDAR index application to these types of matrices are provided in Table 5. Samples were selected for toxicity screening to ensure the presence of different types of contaminants commonly present in complex wastes (e.g., hydrocarbons, DOC, nutrients, ammonia, inorganic anions and cations, pesticides) and other matrices (e.g., sediments and sludges, solid materials, liquid... 

Four types of saturated and olefmic hydrocarbons are characteristic of nearly all organic-matter-rich laminite sediments (Figures 3a-c). This is independent of the presence of alginite as the dominant maceral or a predominance of the... 

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