Bioremediation of a soil industrially contaminated by wood preservatives : degradation of polycyclic aromatic hydro­carbons and monitoring of coupled arsenic distribution

• Two commercially available aerobic bioremediation methods (Daramend® and BioSan) were utilized to study the aerobic biodegradation of polycyclic aro­matic hydrocarbons (PAH) and the effect of the simultaneously present arsenic. The soil was collected at an old wood preservation site and the initial PAH16-concentration was 46 mg/kg, with mainly high molecular weight congeners. The As-concentration was105 mg/kg with low availability as assessed with se­quential extraction. To enahce the availability of PAH, the effect of a non-ionic surfactant was evaluated. Degradation of both low and high molecular weight PAH was observed, however after 30 weeks, the degradation was generally low and no treatment was significantly better than the others. The treatments had, on the other hand, an effect on As-distribution, with increased As-concentra­tion in the available fraction after treatment. This may be due to both the mi­crobial activity and the presence of anoxic micro sites in the soil. The overall efficiency of the biological treatment was further evaluated using the standar­dized ecotoxicity test utilizing Vibrio fischeri (Microtox®). The toxicity test demonstrated that the bioremediation led to an increase in toxicity, especially in treatments receiving surfactant. The surfactant implied an increase in conta­minant availability but also a decrease in surface tension, which might have contributed to the overall toxicity increase.

Subject headings

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

Keyword

Arsenic

Bioremediation

Microtox®

PAH

Surfactant

Environmental chemistry

Miljökemi

Enviromental Science

Miljövetenskap

Publication and Content Type

ref (subject category)

art (subject category)