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||Toronto Harbour Commissioners (THC) Soil Recycle
Treatment Train Applications Analysis Report
The Toronto Harbour Commissioners (THC) have developed
a soil treatment train designed to treat inorganic and organic contaminants
in soils. THC has conducted a large-scale demonstration of these technologies
in an attempt to establish that contaminated soils at the Toronto Port
Industrial District can be treated to attain contaminant levels below
the THC Criteria Levels for Industrial Soils. without utilizing incineration
The THC's treatment train evaluated during this SlTE Demonstration consists
of three soil remediation technologies: an attrition soil washing technology,
inorganic removal by chelation, and a chemical and biological treatment
to reduce organic contaminants. The overall process sequence is determined
by the specific contaminants in the soil to be treated.
Sampling, data collection and analysis as part of the THC demonstration
were conducted under the SITE program utilizing appropriate analytical
procedures as specified in SW846 to provide a consistent basis for comparing
these technologies to other technologies evaluated under the SITE program.
Based on the results of the SITE demonstration project at the THC Soil
Recycling Demonstration Project, Toronto, Ontario, Canada and information
concerning the overall THC project, several conclusions can be drawn.
- The primary developer's claim that the gravel, sand, and fine soil products
will meet the THC criteria for reuse as fill material at industrial/ commercial
sites was achieved by the gravel and sand products, representing 79.6
percent of products. The fine soil representing 18.8 percent of the products
exhibits significant reduction in PAH compounds as a result of biological
processing but did not meet the criteria level of 2.4 mg/kg for benzo(a)pyrene.
- The attrition soil wash plant produced a gravel (
0.24 in) and
a sand (<0.24 in; >0.0025 in) that achieved the primary THC criteria.
It should be noted that the only parameter which exceeded this THC criteria
in the feed was naphthalene. The process exhibited removal rates for organic
contaminants of 67 percent or greater for the gravel product which accounted
for 11.5 percent of the product output. The sand product exhibited organic
removal rates of 78 percent or greater while accounting for 68.1 percent
of the product output. The process concentrated the organic contaminants
into a contaminated fine slurry (<0.0025 in) which accounted for 18.8
percent of the process output while accounting for 74 percent or more
of the organic contaminants.
- The metals contamination levels actually encountered during pilot-scale
processing of the test soil were so low that there was no need to use
the metals removal process. Limited data were developed for the efficiency
of the metals removal process by sampling a run of a metals-rich slurry
from another soil. The reactor achieved the following removal efficiencies:
copper-96 percent, lead-71 percent, nickel-71 percent and zinc-64 percent.
Higher removal efficiencies are claimed by the developer when processing
more highly contaminated soils.
- The bioslurry process exhibited limited reduction in oil and grease. A similar comparison for other parameters yielded the following: TRPH reduction of 60 percent, naphtbalene at least 97 percent, and benzo(a)pyrene approximately 70 percent.