Pyrene fate affected by humic acid amendment in soil slurry systems.
BACKGROUND
Humic acid (HA) has been found to affect the solubility, mineralization, and bound residue formation of polycyclic aromatic hydrocarbons (PAHs). However, most of the studies on the interaction between HA and PAH concentrated on one or two of the three phases. Few studies have provided a simple protocol to demonstrate the overall effects of HA on PAH distribution in soil systems for all three phases.


METHODS
In this study, three doses of standard Elliott soil HA (ESHA), 15, 187.5, and 1,875 mug ESHA/g soil slurry, were amended to soil slurry systems. 14C-pyrene was added to the systems along with non-radiolabeled pyrene; 14C and 14CO2 were monitored for each system for a period of 120 days.


RESULTS
The highest amendment dose significantly increased the 14C fraction in the aqueous phase within 24 h, but not after that time. Pyrene mineralization was significantly inhibited by the highest dose over the 120-day study. While organic solvent extractable 14C decreased with time in all systems, non-extractable or bound 14C was significantly enhanced with the highest dose of ESHA addition.


CONCLUSIONS
Amendment of the highest dose of ESHA to pyrene contaminated soil was observed to have two major functions. The first was to mitigate CO2 production significantly by reducing 14CO2 from 14C pyrene mineralization. The second was to significantly increase stable bound 14C formation, which may serve as a remediation end point. Overall, this study demonstrated a practical approach for decontamination of PAH contaminated soil. This approach may be applicable to other organic contaminated environments where active bioremediation is taking place.
Liang
Yanna
Y
Department of Civil and Environmental Engineering, Southern Illinois University Carbondale, 1230 Lincoln Dr., Carbondale, Illinois, USA.
Sorensen
Darwin L
DL
Utah Water Research Laboratory, Utah State University, 1600 Canyon Road, Logan, Utah, USA.
McLean
Joan E
JE
Utah Water Research Laboratory, Utah State University, 1600 Canyon Road, Logan, Utah, USA.
Sims
Ronald C
RC
Department of Biological & Irrigation Engineering, Utah State University, 4105 Old Main Hill, Logan, Utah, USA.
Environ Pollut. 2001;112(1):27-31
11202651
Environ Sci Technol. 1995 Mar 1;29(3):807-17
22200292
Appl Environ Microbiol. 2006 Dec;72(12):7821-8
17041157
Naturwissenschaften. 1999 Oct;86(10):496-9
10541661
Environ Pollut. 2005 Jan;133(1):85-90
15327859
Sci Total Environ. 1992 Aug 12;123-124:205-17
1439732
Appl Environ Microbiol. 1985 Feb;49(2):402-7
16346726
Environ Sci Technol. 2002 Mar 15;36(6):1276-80
11944680
Environ Pollut. 2005 Jun;135(3):515-22
15749548
Appl Environ Microbiol. 1998 Aug;64(8):3123-6
9687489
Environ Pollut. 2003;126(1):83-91
12860105
Appl Microbiol Biotechnol. 2007 Apr;74(6):1368-75
17216450
J Contam Hydrol. 2002 Feb;54(3-4):277-305
11902159
J Contam Hydrol. 2002 Feb;54(3-4):249-76
11902158
Environ Sci Technol. 1995 Feb 1;29(2):537-45
22201403
Appl Microbiol Biotechnol. 2001 Aug;56(3-4):555-9
11549037
Chemosphere. 1998 Apr;36(10):2211-24
9566297
Biotechnol Bioeng. 2004 Oct 20;88(2):214-23
15449300