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11 D 4874
<br /> ' constant head permeameter of that procedure. If it is and fittings, from the mass of the saturated column.
<br /> determined that it is not possible to saturate the waste using 10.4 Effluent Flow:
<br /> Test Method D 2434, it may be necessary to increase the 10.4.1 Once the column is saturated, begin the testing
<br /> vacuum used in the procedure or attempt to saturate the period Adjust the pressure or hydraulic head, or both, so
<br /> column under pressure, or both, to promote the dissolution that one complete void volume exchange rate is aocom-
<br /> of gasses. plished in 24 t 3 h. Maximum operating column pressure,
<br /> 10.3.3 Water used to saturate the waste should be of the for apparatus specified,should not exceed 275 kPa(40 psig).
<br /> ' same quality as that to be used to leach the waste in the Read and record operating pressure, and effluent start time.
<br /> column. Collect a sample of this water at the time of 1f some test period other than 24 t 3 h (an alternate void
<br /> saturation and analyze for the same properties and constitu- volume period) is warranted, record justification, time in-
<br /> ents as will be measured in the column effluent. An terval required,operating conditions,and effluent start time.
<br /> appropriate sample container,similar to that used for sample Collect all column effluents as discrete void volume incm-
<br /> collection should be chosen and cleaned. Sample container meats•
<br /> guidance it given in 10.6.1.The test portion will be collected 10.4.2 Operating Requirements—The column must be
<br /> using the procedures for leachate collection. operated continuously. Note and record stop and restart
<br /> ' 10.3.4 Determination of the Void Volume—Void volume times for all cessat➢otm Determine total stoppage time for
<br /> is estimated from the measurement of specific gravity of the each occurrence per day and total daily stoppage. Cease test
<br /> solids in accordance with Test Method D 854, the mass of if, on any one day, total stoppage exceeds 1 h.
<br /> the wet solids placed into the column, the moisture content 10.4.3 No type of channeling is permitted. When chan-
<br /> of the material in accordance with Test Method D 2216,and neling is noted,note the time and cease the test.Determine if
<br /> the volume of the column.Although the drying temperatures samples generated previously are usable. Document ratio-
<br /> used in Tat Methods D 854 and D 2216 can be selected on nale for acceptance/rejection of previous sample effluent.
<br /> the basis of the specific characteristics or the material being Columns shall be protected from extraneous light except
<br /> dried, the drying temperatures used in the two procedures during column checks and sample collection intervals. Note
<br /> must be the same for the data to be used for porosity and and record all exposure periods.
<br /> void volume calculations. 10.4.4 Columns are to be run at ambient temperature,
<br /> ' 10.3.4.1 Measure the mass of the sample material which under normal tat conditions. Sufficient pressure is required
<br /> fills the column apparatus. Note and record the moisture to maintain flow at the sped rate which will yield a void
<br /> content of the material,as well as the spec gravity and any volume during the specified time interval. Temperature and
<br /> other specific information relevant to the material. pressures must be read and recorded periodically. For safety
<br /> ' 10.3.4.2 Calculate the void volume using the following reasons, do not operate this equipment above 275 kPa (40
<br /> equation: fig).
<br /> - M 10.5 Leachate Collection:
<br /> V,( ll(I + w)x S x DI) 10.5.1 The column mutt be inspected periodically and
<br /> where: adjustments made if necessary to maintain the desired
<br /> Vo = void volume in the column, CIA 3. operating conditions.
<br /> Vc —volume of the column, eras, 10.5.2 Sufficient leachate from void volume periods shall
<br /> M =as-packed mass of the material, including moisture, be collected to establish a basis for judgment on complete-
<br /> ' contained in the column, ness of the test. Minimally, it is recommended that Void
<br /> w =moisture content of the material contained in the Volumes 1,2,4,and 8 be collected and analyzed.Additional
<br /> column as a mass ratio from Test Method D 2216, g void volumes may provide additional useful data. The
<br /> water/g solids minimum number and sequence numbers of void volumes
<br /> t S —specific gravity of the material as determined in Test that will be collected and analyzed must be identified in
<br /> Methods D 854, unitless,and advance of any collection activity.
<br /> D =density orwater, g/cmr. 10.5.3 Void volumes are sampled by collecting all column
<br /> 10.3.5 Estimate the degree of saturation by calculating the effluent generated over a 24 t 3 h or other period corre-
<br /> ' porosity n of the material using the following equation: sponding to the void volume of interest.
<br /> n v Vi/V, 10.5.4 Minimize contact of the leachate with the atmo-
<br /> sphere. Fill effluent collection vessel head space with pre-
<br /> Calculate the mass gain in the saturated material. Add the purified nitrogen or argon. Protect vessel head space with a
<br /> value of the mass gain to the mass of the water in the packed water trap.
<br /> column. Compare the value to the calculated void volume. 10.5.5 Collect effluent in appropriate containers. Con-
<br /> The ratio is the degree of saturation.The degree of saturation tainers shall be cleaned in an appropriate manner. Con-
<br /> can be estimated by determining the mass gain due to the tainers must be free from contamination for those parame-
<br /> water added to the waste during the saturation process, 1ers of interest in the leachate. Follow the procedures
<br /> adding this mass gain to the mass of water in the packed outlined in Practice D 3694 or Ref(4),or both.
<br /> column before saturation, and comparing this to the void 10.6 Leachate Sample Preparation:
<br /> ' volume just calculated.The mass gain can be determined by 10.6.1 Sample containers must be constructed of mate-
<br /> subtracting the mass of the packed,unsaturated column plus rials that do not alter the sample quality. Follow the
<br /> the mass of the packed,unsaturated column plus the mass of procedures outlined in Practice D 3694 or Ref(4), or both.
<br /> the water retained in the end plates, flow distribution disks, 10.6.2 Sample containers must be cleaned according to
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