Characterisation of PAH-contaminated sediments in a remediation perspective

1998 ◽  
Vol 37 (6-7) ◽  
pp. 157-164 ◽  
Author(s):  
M. P. Cuypers ◽  
J. T. C. Grotenhuis ◽  
W. H. Rulkens
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Solvent Extraction ◽  
Physical State ◽  
Water Mixture ◽  
Particle Size Fractions ◽  
Acetone Water ◽  
Particulate Form ◽  
Further Development ◽  
Harbour Sludge

To support the choice of a remediation technique for the decontamination of PAH contaminated dredged sediments a characterisation test is needed, that takes into account the physical state in which PAHs occur. Here, solvent extraction is proposed as such a characterisation test. Solvent extraction experiments were performed with a 1/1 acetone-water mixture on (particle size fractions of) PAH-contaminated harbour sludge. The PAHs were more easily dissolved from fine than from coarse fractions, which indicates that the PAHs in the fine fractions are better (bio)available. The results further suggest that PAHs were present in particulate form, absorbed in organic matter and dissolved in oil. The performed extraction experiments provide a basis for further development of existing models.

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Size Fraction ◽  
Organic C ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Clay Size Fraction ◽  
Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

Sources of organic matter in first flush runoff from urban roadways

2015 ◽  
Vol 72 (7) ◽  
pp. 1234-1242 ◽  
Author(s):  
K. Wada ◽  
N. Takei ◽  
T. Sato ◽  
H. Tsuno
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Carbon Content ◽  
Road Dust ◽  
Organic Carbon Content ◽  
Water Mixture ◽  
First Flush ◽  
The Road ◽  
Organic Carbon Concentration

This study aims to explore the influential sources of organic matter in first flush runoff from urban roadways by comparing organic carbon content and particle size distribution in road dust with those from discharge from vehicles during rainfall. Samples on first flush runoff and road dust were collected from urban roadways. In addition, vehicle drainage was assumed to flow from vehicles during rainfall events, so vehicle wash-off water was collected by spraying water onto the top and from the underside of vehicles to simulate accumulation during a vehicle run. In road dust, the organic carbon content in the <0.2 mm fraction was about twice that of the 0.2–2 mm fraction. The particle size distributions of both first flush runoff and vehicle wash-off water were similar, and particles <0.2 mm contributed to over 95% of the total volume. The dissolved organic carbon concentration in the vehicle wash-off water was considerably higher than that in the road dust/water mixture. The total organic carbon content in road dust was positively correlated with annual daily traffic. Therefore, vehicles were thought to strongly influence the nature of road dust.

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