Model Trials for Phytoremediation of Hydrocarbon-Contaminated Sites by the Use of Different Plant Species

Abstract

In order to further the development of plant-based remediation of sites contaminated by carbo-chemical and petro-chemical industries, the penetration of the roots of Phragmites australis in contaminated soil substrate was studied in model trials. The series of experiments contained model substrate with firm bitumen and tar. In terms of the level of root penetration, the roots and rhizomes penetrated equally through the middle of the pot and at the edges as well as coming up through the bottom. There were differences between the density of the root systems in the topsoil of the two variations, with the roots in the sample with a 3.5-cm bitumen layer being more dense. The experiment also showed that shallow rooting plants can penetrate thick barriers and are suitable for planting in contaminated areas. In the subsoil zone, which contained many roots, a reduction of up to 85% in the MOH content was observed. In a second series of long-term pot experiments, the stimulation of hydrocarbon remediation by Phragmites australis, Alnus glutinosa, and Robinia pseudoacacia was studied. In the subsoil zone, which contained many roots, a reduction of up to 64% in the hydrocarbon content was determined. In the comparison between the cropped and noncropped treatments, the decontamination ratio was up to 40% higher in the cropped pots than in the pots without plants. For a determination of microbial activity, two enzymes (catalase, ß-glucosidase) and microbial biomass were measured. Variants with plants showed higher microbial activities than uncropped pots. By increasing "biostimulation," pollution and also the leaching of pollutants can be reduced.

Microbial biomass and enzyme activities on soil monitoring sites in Saxony-Anhalt, Germany

“…ß-glucosidase activity was significantly lower in the field sites and mine spoil than in the grassland. This result agrees with a large body of other work showing that ß-glucosidase can differentiate between various soil management systems and that it is a consistent indicator of soil quality (Bandick & Dick 1999;Tischer & Hü bner 2002;Rinklebe 2004). ß-glucosidase activity showed a correlation with microbial biomass (0.72**) and organic matter (0.34**).…”

Phytoremediation of hydrocarbon-contaminated soils with emphasis on the effect of petroleum hydrocarbons on the growth of plant species

“…plants on total oil and grease (TOG) content in soil. In a phyoremediation study by Tischer and Hubner (2002), Phragmites australis (Car.) Trin.…”

Phytodegradation Potential of Erythrina crista-galli L., Fabaceae, in Petroleum-Contaminated Soil

“…in petroleum-contaminated soil and attributed this response to the low redox potential of the soil. The presence of roots increases microorganism populations, improves the physical structure of the soil, and enhances hydrocarbon degradation [11].…”