Sludge Watch ==> USGS - Biosolids -Survey of Organic Wastewater Contaminants

[maureen.reilly at sympatico.ca]

Here are some highlights. Full report is attached as PDF file.


You might want to look at this on the webpage, since there are a number of 
live links.
Do download the full report...it is very important work.


http://pubs.acs.org/subscribe/journals/esthag-w/2006/sep/science/nl_composting.html

Science News –September 13, 2006
Composting industrial waste
The first U.S. survey of wastewater treatment solids destined to become 
fertilizer turns up numerous emerging contaminants.
Rich in nitrogen, phosphorus, and other nutrients, the sludge left over from 
wastewater treatment often ends up as fertilizer that is spread on farm 
fields or packaged into bags and sold at garden shops. This material—known 
as biosolids—also carries an unknown load of potentially harmful chemicals. 
In the first comprehensive analysis of biosolids from a variety of 
wastewater treatment plants in the U.S., published today on ES&T’s Research 
ASAP website (DOI: 10.1021/es0603406), researchers document emerging 
contaminants in biosolids collected at treatment plants.


USGS
Biosolids (shown here)—as liquid sludge, solid compost, or pellets left over 
from wastewater treatment—can be applied to farmlands as beneficial 
fertilizers, but the materials can carry undesirable compounds.Biosolids are 
often available for public purchase, says Chad Kinney of Eastern Washington 
University, who conducted the study along with a team of U.S. Geological 
Survey (USGS) researchers. The scientists examined 9 biosolid products from 
8 wastewater treatment plants scattered across the U.S. and tested them for 
87 compounds. They found that the concentrations of some compounds remained 
relatively constant over time. Of the 87 compounds, 55 cropped up in one or 
more of the biosolids studied, with concentrations ranging between 10 and 
20,000 µg/kg dry weight.

“One of the things that surprised us was the diversity of compounds that we 
found,” says Ed Furlong of USGS, a coauthor of the research. For example, 
because of the volatility of fragrance chemicals, he expected their 
concentrations to be low. Instead, the fragrance molecules seemed to stick 
around, despite extensive processing of the biosolids. The team hypothesized 
that the organic matrix of the biosolids acts to retain these chemicals.

As researchers with Environment Canada documented in 2002, biosolids can 
retain pharmaceuticals and other pollutants at concentrations high enough to 
raise red flags. For example, their report found nonylphenol, an endocrine 
disrupter, at a median concentration of 232 µg/g dry weight.

Kinney says that analyzing biosolids for contaminants is difficult for 
numerous reasons. Wastewater treatment plants use different methods and take 
in waste that changes over time. The processing and variable makeup of 
biosolids—from liquid to pellet to compost—also alter which chemicals are 
destroyed and which survive. In the end, how the biosolids are applied can 
also affect chemical survival. Folding the waste into soil may increase 
biodegradation, Kinney says, and photodegradation may come into play if the 
biosolids are simply dumped on soil surfaces.

Furlong emphasizes that all biosolids must follow U.S. EPA regulations. He 
points out that the team found triclosan at levels of only a few thousand 
micrograms per kilogram. “That’s a low concentration,” he says, but “if 
they’re persistent, or not degraded, which we don’t yet know, it just shows 
that there’s not enough information to say what that [concentration] means.”

Biosolids may contain residues from many commercial products, not just 
pharmaceuticals and consumer products, says Rolf Halden of Johns Hopkins 
University. Halden recently published results in ES&T showing that biosolids 
contain triclosan and triclocarban, antibacterial compounds commonly used in 
soaps. He says the new work provides a challenge and a first step in 
identifying the chemicals that might be present in biosolids. He also notes 
that sludge is difficult to analyze and that the reported levels are 
probably quite conservative.

“It’s very hard to think of anything more difficult to analyze than sludge. 
It’s clear that this is not an easy matrix to work with,” Halden says. 
“We’re just beginning to understand what the consistency of the sludge is, 
... what it contains, and what it means for human health.” —NAOMI LUBICK


....................................................................................................
Survey of Organic Wastewater
Contaminants in Biosolids Destined
for Land Application†

C H A D A . K I N N E Y ,‡
E D W A R D T . F U R L O N G , *,
§
S T E V E N D . Z A U G G ,§
M A R K R . B U R K H A R D T ,§
S T E P H E N L . W E R N E R ,§
J E F F E R Y D . C A H I L L ,§ A N D
G R E T C H E N R . J O R G E N S E N§

Department of Chemistry, Eastern Washington University,
Cheney, Washington 99004-2440, and National Water Quality
Laboratory, U.S. Geological Survey, P.O. Box 25046, Denver
Federal Center, Denver, Colorado 80225-0046



"These results indicate that the biosolids investigated in this study have
OWC compositions and concentrations that are more similar
than different and that biosolids are highly enriched in
OWCs (as mass-normalized concentrations) when compared
to effluents or effluent-impacted water. These results
demonstrate the need to better describe the composition
and fate of OWCs in biosolids since about 50% of biosolids
are land applied and thus become a potentially ubiquitous
nonpoint source of OWCs into the environment.'

"Organic wastewater contaminants (OWCs) are organic
compounds produced to offer improvements in industrial,
medical, and household products and applications (10) and
usually are found in human- and agriculture-derived wastewater.
Compounds that can be classified as OWCs include
pharmaceuticals, hormones, detergent metabolites, fragrances,
plasticizers, and pesticides (11). Many OWCs enter
and leave WWTPs unaltered or incompletely removed and
subsequently have been identified in the environment (10-
13)."

" However, potential
concerns about the environmental presence of OWCs include
adverse physiological effects, increased rates of cancer, and
reproductive impairment in humans and other animals as
well as antibiotic resistance among pathogenic bacteria (18-
25). Impacts on human health of chronic exposure to
subtherapeutic concentrations of pharmaceuticals and the
potential for OWCs to effect terrestrial and aquatic organisms
also are poorly understood (10)."

"Because WWTP influent is segregated into
two components, biosolids and liquid effluent, a large fraction
of the total OWCs entering WWTPs ultimately could reside
in biosolids.

"In total, 55 of the 87 OWCs were detected in one or more of
the biosolids studied. The 55 OWCs detected for each biosolid
appear in Table S1 as well as average concentrations, . . ."

" Most notably there were several
pharmaceuticals, detergent metabolites, sterols, synthetic
fragrances, and polycyclic aromatic hydrocarbons (PAHs)
that were detected in all nine biosolid products. It is evident
that despite the variety of biosolid production techniques,
the total number of OWCs detected in any one biosolid does
not vary greatly between products, suggesting some compositional
uniformity of OWCs in biosolid products. "

"While some compositional and concentration differences
do exist between the nine biosolids tested, which may reflect
the different preparation technologies, it can be stated that
the wastewater treatment processes and biosolid preparation
methods for the biosolids studied are inadequate to completely
remove 25 of the OWCs measured (Tables S1 and 2)."

"
105 , for 4-tert-octylphenol and
total para-nonylphenol. Although individual OWCs were
detected at microgram-per-kilogram dry-weight concentrations,
the total sum of all OWCs measured in this study and
detected in a given biosolid approached or exceeded 100
mg/kg dry weight."

". . . when applied to soil or discharged to
surface water. However, it has been demonstrated that some
OWCs show endocrine-modulating activity and that exposure
to these compounds may result in chronic effects on aquatic
organisms at ambient environmental concentrations "

" The common
practice of repeated land application of biosolid products
upon individual sites, therefore, could result in substantial
localized concentrations of known and potential endocrine modulating
and pharmacologically active contaminants, such
as nonylphenol ethoxylates, PAHs, and carbamazepine.

Low levels of antibiotics originating from WWTPs have
been directly linked to an increased presence of antibiotic
resistance among bacteria in aquatic environments (23-25,"

" The biosolids in this study originate from differing
locations and populations, represent at least four distinct
preparation techniques, and show a striking compositional
uniformity (Tables 1 and 2; Table S1). This suggests that when
considering wastewater-derived contaminants, biosolids and
wastewater effluent need to be considered as two distinct
and equally important sources of OWCs to the environment.

Because of the wide variety of uses for biosolids (8) and the
variety of OWCs found in these biosolids, it is likely that
biosolids can constitute a ubiquitous nonpoint source of
OWCs to the environment when land applied."

" Following USEPA
guidance on agricultural application rates for biosolids, 10
dry tons per acre or 116 000 gallons wet septage (2% solid
material) would be representative rates for many crop types
(62). When this representative application rate and the
average concentration of OWCs found in Table S1 are used,
loadings of about 3.4 kg/acre (0.83 g/m2 ) of total OWCs
measured in this study result as well as about 0.2 g/acre (49
íg/m2 ) of the pharmaceutical carbamazepine, 20 g/acre (4900
g/m2 ) of the disinfectant triclosan, 36 g/acre (8900 íg/m2 )of
the synthetic musk tonalide (AHTN), and 760 g/acre (16 000
íg/m2 ) of para-nonylphenol detergent metabolites. These
loading estimates are for a single application; biosolids often
are applied multiple times to the same site. "

"This study was not designed to investigate the environmental
fate of OWCs originating from land application of
biosolids. However, the high frequency of OWC detection in
the biosolids tested and the high concentrations of individual
OWCs present suggest that biosolids can be an important
OWC source to terrestrial environments, and projections
about their environmental fate are warranted. Previous
research has demonstrated that some compounds, including
some synthetic fragrances, pharmaceuticals, and brominated
fire retardants, can be persistent once introduced into soil
environments "

63). Matscheko et al. (63) observed brominated fire retardants at almost 
8000 times higher than
background concentrations in soil samples 20 years after the
last application of biosolid.    (why didn't they cite Rob Hale's seminal 
research on brominated flame retardants in sludge ? )

". . . and Rabølle and Spliid (66) monitored rapid and
complete leaching of the antibiotic olaquindox through soil." (to 
groundwater ? )

"Traina et al. (67) used a multiyear field dissipation study and
laboratory studies to evaluate the persistence or degradation
of polydimethylsiloxane (PDMS) in biosolids-amended plots
and in laboratory studies; they showed that soil moisture
was the controlling factor in the persistence or degradation
of PDMS and that there was no direct effect of biosolids on
PDMS persistence or degradation. These previous studies
suggest that the brominated flame retardants, fragrances,
pharmaceuticals, and surfactant degradates determined in
biosolids from this study would be expected to persist or
degrade similarly after land application."

"Additional research is needed to determine if in fact these
results are representative of most biosolids, in the United
States or internationally. The U.S. Environmental Protection
Agency estimated in 1998 that 6.9 million dry mg of biosolids
was produced in the United States, and this is expected to
increase to 8.2 million dry mg by 2010 (8), of which 50% or
more is destined for land application (1). In addition to
measuring OWC content in a greater number of biosolids,
future research needs to address the transport and behavior
of OWCs derived from land application of biosolids under
realistic field conditions and in laboratory settings. "

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