Miljøprojekt Nr. 1193 – Termisk assisteret oprensning af høfdedepotet, Høfde 42, Harboøre Tange

Termisk assisteret oprensning af høfdedepotet, Høfde 42, Harboøre Tange

Bilag H

Eksperimentel design - Kemron (engelsk)

THERMAL PESTICIDE STUDY

FOR THE CHEMINOVA PLANT IN DENMARK

TEST PLAN

KEMRON developed the Denmark Thermal Pesticide Study scope of work in accordance with the information presented to KEMRON by TerraTherm. The treatability study, as outlined below, will be performed to identify buffering capacity, alkaline hydrolysis, and thermal treatment of the site materials. Specific compounds of concern include pesticides and mercury. The following sections of this scope of work present information regarding the protocols that will be followed in completing the treatability study.

The treatability study will be conducted on soils and waters provided by TerraTherm from the site located in Denmark. The treatability study, as outlined herein, will be performed in order to collect data for TerraTherm to characterize the site material’s buffering capacity and potential to thermally treat contaminants. Throughout the course of this study KEMRON will complete the treatment protocols and sample extraction activities as stated in this test plan. Sample extracts and test waters will be shipped to Cheminova for sample analysis of pesticides and polar compounds, respectively. Mercury in the related soils will be tested at the KEMRON laboratory located in Marietta Ohio. Treatment effectiveness will be assessed by TerraTherm since KEMRON is not currently tasked with receiving the analytical data from the Cheminova analyses.

Sample Receipt and Untreated Material Characterization

As outlined by TerraTherm, KEMRON understands that one site ground water sample material and two site soil materials will be collected for treatability testing. Based on the anticipated scope of work outlined herein, KEMRON believes that one five-gallon bucket of each of the untreated site soils and one five-gallon bucket of the site groundwater will be sufficient to complete the treatability study as outlined.

Upon receipt, the untreated materials will be logged in and placed into refrigerated secure storage (maintained at a temperature of 4°C). Sample homogenization will follow material receipt, where instruction will be given from TerraTherm as to which of the soil materials to initially prepare for testing. Soil homogenization will include placing the chilled site soil into a stainless steel mixing basin followed by gentle mixing using low energy mixing techniques.

Once homogenization of the site soil is complete, representative aliquots will be collected for initial testing. The following tests will be performed on the untreated soil in accordance with the referenced test methods:

Parameter Method

Moisture / Solids Content ASTM D2216

Bulk Density ASTM D2937

Dry Density Calculated

Material pH EPA Method 9045C

Solid Specific Gravity ASTM D854

Porosity Calculated

TOC EPA Method 9060

CEC TBD

Water Saturation Calculated

All characterization tests will be conducted in general accordance with the specified methods and in direct accordance with KEMRON’s Standard Operating Procedures (SOPs).

Test I: Buffering Capacity

Test Materials

The materials necessary for testing include the following:

1N NaOH
Stir Plate
Stir Bar
Beaker
Burrett
pH Meter

Site Sample Quantities

The site sample quantities necessary for testing include the following:

300g soil
100g water

Procedure

The buffering capacity of the site materials will be conducted on a composite sample developed by combining the site soil and groundwater at a ratio of 3:1 soil to groundwater, simulating potential site conditions. The test sample composite will be placed on a laboratory magnetic stirrer to provide continuous mixing throughout the titration. A 1 Normal (N) solution of sodium hydroxide (NaOH) will then be added to the composite material in increments to be determined based on the change in material pH observed during testing. That is, a quantity of the base will be added to provide a measurable change without excessively increasing the material pH. At each NaOH addition, KEMRON will measure the material pH of the sample using an Orion bench-top pH meter. Once a stable reading has been accomplished, KEMRON will record the quantity of titrant added and the pH at each addition. This will be repeated until data is collected for a pH of 7, 10 and 12 which is the target range for the study; however, the titration will be completed until the pH exceeds 14. Based on the data collected from testing, KEMRON will determine the pH buffering capacity of the composited site materials (in particular, the base needed for increasing pH of the test composite to 7, 10, and 12).

Test II: Alkaline Hydrolysis Testing

Alkaline Hydrolysis Testing Materials

The materials necessary for testing include the following:

1N NaOH
Stir Plate
Stir Bar
Beaker
Burrett
pH paper
1-L amber glass jars w/ septum caps
Stainless steel stir rod
Syringe / needle
Stainless steel tubing
Swagelok fitting
Female quick connect
40 mil vials (quantity 28)
Refrigerator (10°C)
Oven (70°C)
Pressure transducer
Tedlar Bags (min 4)
Water displacement apparatus
Gas monitors
pH paper

Sample Extraction Testing Materials

The materials necessary for sample extraction include the following:

Extraction vials (4 soil + 4 water + 1 control for each = 10)

3.5% NaCl

Isopropyl acetate (analytical grade)

Shaker (end over end)

2-ml amber vials

25-ml amber vials

Site Sample Quantities

The site sample quantities necessary for testing include the following:

Total soil quantities: 2736g

Total groundwater quantities: 912g

Alkaline Hydrolysis Testing Procedure

Batch hydrolysis testing will be performed to evaluate the breakdown of pesticides under saturated conditions and the effects of temperature and pH on contaminant breakdown. During this phase of testing KEMRON will prepare four batch reactors. Each reactor will consist of a pre-cleaned 1-liter amber glass container, 600 grams of site soil and 200 grams of site groundwater. The test material inside each reactor will be thoroughly mixed, using stainless steel stir rods. Prior to testing, an aliquot of each reactor will be removed, mixed together to form one composite sample. This sample will be chilled for extraction per the method provided by TerraTherm and provided later in this document. The resulting extract will be forwarded to Cheminova for analytical testing. These “control” samples will be used to establish a baseline of contaminant concentrations in each reactor for determination of treatment effectiveness.

Following sampling of the control specimens, two of the reactors will be titrated to a pH of 10 standard units (s.u.), using 1N solution of NaOH. The other two reactors will have the unchanged ambient pH. Each reactor will then be capped using a screw on top equipped with a septum. The duration of the testing will occur in a dark environment.

As outlined in the Request for Proposal (RFP), each reactor will be monitored daily for off-gas production. In order to measure pressure buildup and to estimate the quantity and chemical make-up of off-gas generated from the test materials, each reactor will be equipped with a system to collect off-gas. This system will consist of a syringe type needle which will be inserted through the septum located in the cap of each reactor, and positioned into the headspace of each reactor. This needle will then be attached to stainless steel tubing using a SwageLok type fitting, and an airtight female quick connect will be attached to the opposite end of the tubing. Finally, a tedlar bag will be quick connected to the system providing a closed system and a means to collect any pressurized off-gases.

Additionally, KEMRON has been tasked with daily pH monitoring of the test reactors. For pH monitoring, KEMRON will prepare 7 additional “mini reactors” for each of the four test specimens. These mini reactors will be prepared using the same protocol employed to develop the four main reactors; however, the quantities of site materials will be scaled down to 12g of soil and 4g of groundwater per reactor.

Testing will be initiated by placing one neutral (no pH adjustment) reactor and one reactor adjusted to a pH of 10, along with the appropriate pH mini reactors, into refrigeration maintained at a temperature of 10°C. The remaining reactors and pH mini reactors will be placed into an oven maintained at a temperature of 70°C. Throughout the 7-day test duration, KEMRON will evaluate pressure buildup by visual observation of the tedlar collection bag. If the tedlar bag indicates pressurized gases have evolved (i.e., the bag has inflated) the tedlar bag will be disconnected and a pressure transducer will be connected to the reactor. Note, there is the possibility of excessive pressure build up and possible rupturing of the reactor septum and therefore pressure monitoring will be conducted on a limited basis. That is KEMRON anticipates that pressure monitoring will be performed until a maximum of 5 pounds per square inch (psi) is observed, equilibrium is reached, or a monitoring duration of two hours is accomplished, which ever occurs first. Equilibrium will be determined by a steady pressure reading.

Following pressure monitoring the transducer will be detached from each reactor and a Tedlar sampling bag will be attached to the quick connect fitting, assuming that pressurized gases are building up. In the event that substantial off-gas production is observed, multiple Tedlar bags will be utilized. Off-gas collection will be conducted until the beginning of the following work day. At the conclusion of each off-gas collection event, KEMRON will estimate the volume of gas collected to be determined using water displacement. Additionally, KEMRON will evaluate chemical parameters including diethyl sulfide, H₂S, SO₂, SO, H₂, CH_4,NO, NO₂, O₂, CO, and CO₂. Phosgene gas will be analyzed by collecting the sample in a Tedlar bag and then bubbling the sample through toluene. The toluene extract will then be shipped to a laboratory as directed by TerraTherm. Monitoring of the chemical parameters listed above will be performed on the off-gas contained in the Tedlar bags using various real-time gas meters and/or Dragger gas analyzing tubes. In the event that KEMRON observes limited or no off-gas production, analyses will not be performed or anther method of analysis will be completed (i.e., headspace analysis).

In addition to off-gas monitoring, KEMRON will daily evaluate any change in material pH by testing one pH mini reactor for the corresponding main test reactor. Note that if KEMRON observes significant pressure build up in the main reactors, each pH test vial will be vented as necessary.

Following the 7-day test duration, each test reactor will be chilled to approximately 4°C. Aliquots of soils from each chilled test reactor will then be removed and extracted using procedures provided by TerraTherm. The resulting extracts will be shipped to Cheminova for analytical testing. Additionally, the water fraction will be sampled and then frozen for later shipment to Cheminova for analysis of polar compounds. Additional soil samples will be collected for mercury analysis.

Sample Extraction Procedure

1 gram of the chilled material is pulled from the more solid portion of the study material.

Add 10 ml of 3.5% NaCl

Add 2 ml of isopropyl acetate (IPA)

Shake end over end for 1 hour

Remove IPA extract (~2 ml) and store with Teflon-lined septa in a cold dark location

Test III: Thermal Treatment Testing

Thermal Treatment Testing Materials

The materials necessary for testing include the following:

Reactor w/ gasket
Stainless steel lines
Temperature monitors
Muffle furnace
Drying oven
Stainless steel coil
Swagelok fittings
Heating tape
Flow meters (min 3)
Compressor
Steam container
Desiccator
Flex tubing
Quick connect pair
Pumps
Ice water bath
Grandulated Carbon
Flasks (2)
Condenser (1)
Steam source

Material Quantities

Total soil quantities: 3375g
Total groundwater quantities: 1125g + 70C treatment quantities

Thermal Testing Procedure

Thermal treatment testing will be performed in order to evaluate the potential destruction of pesticides under elevated temperatures. Treatment will be conducted at temperatures including 70, 100, and 300 °C. Testing will be conducted on a combined site material prepared at a soil to groundwater ratio of 3:1. No pH adjustments will be made. Treatment at a temperature of 70 °C will include passing approximately 10 pore volumes of the site groundwater through the test soil over a period of approximately 7 days. Prior to introducing the groundwater through the soil reactor, KEMRON will heat the site water to 70 °C. Similarly, the 100 °C treatment will include passing approximately 10 liters of deionized (DI) water, in the form of steam, through the test soil. Note that both the heated site groundwater and the steam will be introduced to the soil through a manifold placed within the site soil material.

Because of the elevated moisture content of the test material KEMRON anticipates performing thermal testing using a stainless steel mixing box rather than a cylinder or column. Immediately prior to adding the untreated site composite material to the reactor, aliquots of the test material will be collected and chilled for extraction using protocol provided by TerraTherm. Extracts will be shipped to Cheminova for analysis. Additionally, untreated soil will be forwarded to KEMRON’s analytical laboratory located in Marietta, Ohio for mercury analyses.

A stainless steel reactor measuring approximately 8 inches in length, 4 inches in width, and 3 inches deep will be used to hold the untreated composite material during heating. The thermal reactor will be closed with a stainless steel lid and gasket. The lid is fitted with ports for temperature monitoring as well as ports for inflow and outflow water/gas lines. KEMRON anticipates that approximately 1,500 grams of material will be added to the reactor for each test.

The test set-up will include placing the reactor with the site composite into a suitable oven (i.e., muffle furnace or drying oven). A second drying oven will be used to heat site groundwater and/or generate steam, which will be injected into the soil reactor for the 70 and 100°C, respectively. The steam will be generated from deionized water. Heating of the water will be accomplished by pumping through a stainless steel coil placed inside of the drying oven. The oven temperature will be set to heat the applicable water to the target temperature of the soil treatment being performed (i.e., 70 or 100°C). The applicable water will be continuously pumped through the coil and heated, then will exit the oven via stainless steel tubing which will be connected to a SwageLok connection located on the top of the thermal reactor in the oven. To ensure delivery of the applicable water/steam at the appropriate temperature, any tubing located outside of either oven will be wrapped in heating tape. The temperature of the heating tape will be adjusted to maintain the target soil temperature (i.e., 70 or 100°C).

70°C Testing

The reactor with a target temperature of 70°C will receive approximately 10 pore volumes of site groundwater over a period of 7 days, with a relatively uniform flow rate. Note that the quantity of water required to achieve 10 pore volumes will be determined based on the actual quantity of the composite material utilized.

100°C Testing

The reactor with a target temperature of 100°C will be heated slowly over a 24-hour period to 100°C, followed by the injection of the 2 pore volumes of steam generated from clean water. The steam will be injected as uniformly as practical by heating the coil in a separate oven to approximately 110°C as discussed earlier. The flow of the approximately 2 pore volumes will occur over a period of 7 days. Note that the quantity of water required to achieve 2 pore volumes of steam will be determined based on the actual quantity of the composite material utilized.

300°C Testing

Water or moisture will be not introduced into the 300°C reactor during testing; however the test reactor will initially produce steam from the testing material until the material becomes dry.

Treatment at each temperature will be conducted for a period of 7 days. Outflow stainless steel lines are positioned at the top of the reactor for off-gassing or water movement out of the reactor. This outflow tubing will exit the oven and be connected to a condensing tube, as necessary, and collection flask. Throughout the treatment process, KEMRON will record the test soil and oven temperatures at 15 minute intervals using a DigiSense Dual Thermocouple Datalogger. If feasible, gas analysis will occur when thermal treatment overlaps with the gas monitoring for the batch hydrolysis study.

At the conclusion of each thermal test the soil reactor will be removed from the oven and chilled to 4°C. The chilled treated material will then be extracted using the previously mentioned protocol and the extract will be forwarded Cheminova for testing. An additional aliquot of treated soil will be submitted to KEMRON’s analytical laboratory for mercury analysis.

Reporting

Throughout the project, KEMRON will provide interim updates via facsimile or electronic mail as data is received. Detailed discussion of all protocols utilized during the study will be presented, as well as any conclusions and recommendations based on the study. Upon completion of the project, a detailed final report will be developed including thorough discussions of all testing protocols and the results of all analyses/testing performed by KEMRON. Any information relative to performance of the treatability study will be presented, as well as recommendations and conclusions developed based on this information.