TY - JOUR

T1 - Impact of Al and Fe on the development of phenanthrene catabolism in soil

AU - Obuekwe, Ifeyinwa S.

AU - Semple, Kirk T.

PY - 2013/10

Y1 - 2013/10

N2 - Heavy metals often occur as co-contaminants with polycyclic aromatic hydrocarbons (PAHs) and reportedly have adverse effects on biodegradation. In this study, the development of C-14-phenanthrene mineralisation in soil co-contaminated with aged or freshly added Al or Fe amendment was assessed.C-14-phenanthrene mineralisation was assessed using respirometry; respirometers incorporated a Teflon-lined screw-capped CO2 trap containing 1-M NaOH within a glass scintillation vial. The production of (CO2)-C-14 was assessed by the addition of Ultima Gold liquid scintillation fluid to the CO2 traps and subsequent liquid scintillation counting. Enumeration of phenanthrene-degrading bacteria was achieved by counting the colony forming unit count using the spread plate method.This investigation considered the effects of Al and Fe (50, 100, 250 and 500 mg/kg) on C-14-phenanthrene biodegradation in soil over 63-day contact time. Fresh Al amendments at lower concentrations (50 and 100 mg/kg) stimulated phenanthrene catabolism (p <0.05) at t = 21 and 42 days which may reflect an 'Arndt-Schulz' effect, but phenanthrene catabolism was significantly reduced (p <0.05) in 500 mg/kg aged Al this could be due to Al toxicity to phenanthrene degraders. Phenanthrene mineralisation was stimulated in the highest Fe concentration (500 mg/kg) in aged and fresh Fe amendments at t = 21 days. This could be because Fe is an essential requirement for microbial growth.The impact of Al or Fe on the catabolism of C-14-phenanthrene was dependent on incubation time and Al was more toxic than Fe to soil PAH catabolic activity. This could be because Al is a non-essential microbial requirement. Bioremediation of soils co-contaminated with PAH and heavy metal is a complex problem; therefore, studies on the impact of metals on PAHs biodegradation highlight the risks and biodegradation potential in contaminated soil.

AB - Heavy metals often occur as co-contaminants with polycyclic aromatic hydrocarbons (PAHs) and reportedly have adverse effects on biodegradation. In this study, the development of C-14-phenanthrene mineralisation in soil co-contaminated with aged or freshly added Al or Fe amendment was assessed.C-14-phenanthrene mineralisation was assessed using respirometry; respirometers incorporated a Teflon-lined screw-capped CO2 trap containing 1-M NaOH within a glass scintillation vial. The production of (CO2)-C-14 was assessed by the addition of Ultima Gold liquid scintillation fluid to the CO2 traps and subsequent liquid scintillation counting. Enumeration of phenanthrene-degrading bacteria was achieved by counting the colony forming unit count using the spread plate method.This investigation considered the effects of Al and Fe (50, 100, 250 and 500 mg/kg) on C-14-phenanthrene biodegradation in soil over 63-day contact time. Fresh Al amendments at lower concentrations (50 and 100 mg/kg) stimulated phenanthrene catabolism (p <0.05) at t = 21 and 42 days which may reflect an 'Arndt-Schulz' effect, but phenanthrene catabolism was significantly reduced (p <0.05) in 500 mg/kg aged Al this could be due to Al toxicity to phenanthrene degraders. Phenanthrene mineralisation was stimulated in the highest Fe concentration (500 mg/kg) in aged and fresh Fe amendments at t = 21 days. This could be because Fe is an essential requirement for microbial growth.The impact of Al or Fe on the catabolism of C-14-phenanthrene was dependent on incubation time and Al was more toxic than Fe to soil PAH catabolic activity. This could be because Al is a non-essential microbial requirement. Bioremediation of soils co-contaminated with PAH and heavy metal is a complex problem; therefore, studies on the impact of metals on PAHs biodegradation highlight the risks and biodegradation potential in contaminated soil.

KW - Aluminium

KW - Catabolism

KW - Iron

KW - Phenanthrene

KW - Soil

KW - POLYCYCLIC AROMATIC-HYDROCARBONS

KW - HEAVY-METAL CONTAMINATION

KW - NAPHTHALENE BIODEGRADATION

KW - MICROBIAL-DEGRADATION

KW - AGRICULTURAL SOILS

KW - PYRENE CATABOLISM

KW - CADMIUM TOXICITY

KW - ALUMINUM

KW - COPPER

KW - PAHS

U2 - 10.1007/s11368-013-0759-2

DO - 10.1007/s11368-013-0759-2

M3 - Journal article

VL - 13

SP - 1589

EP - 1599

JO - Journal of Soils and Sediments

JF - Journal of Soils and Sediments

SN - 1439-0108

IS - 9

ER -