Encyclopedia of Environmental Science and Engineering, Volume I and II

1118 STACK SAMPLING

used in the succeeding calculations for determining the mass

of mercury in the original sample solution. This value is then

combined with the stack and flow volume factors in the same

way as for Method 5 to arrive at the total mercury emission

rate, in grams/day. Isokinetic variation and test acceptability

are also determined according to Method 5 criteria.

The EPA Method 101 write-up contains detailed instruc-

tion for each of these steps, along with estimates of range,

sensitivity, accuracy, precision, possible interferences and

a list of references. It should be read in detail before the

Method is attempted. Also, as with all of these methods,

testing should be performed only by trained and experienced

personnel using equipment and materials designed for this

purpose.

Test Method 101A

Test Method 101A is used to determine total particulate and

gaseous mercury (Hg) emissions from sewage sludge incin-

erators. It is almost identical to Method 101. The gas stream

is sampled isokinetically using, essentially, a Method 5

sampling train and bubbled through an acidic potassium

permanganate (KMnO 4 ) solution where the mercury is col-

lected and held in solution. During subsequent analysis, the

mercury is reduced to elemental form, and aerated into an

optical cell where it is analyzed by an atomic absorption

spectrophotometer.

The main differences from Method 101 are as follows:

• There are two main differences in the sampling
  train. First, the impingers are filled with an acidic
  solution of 4 percent KMnO 4 solution instead
  of ICl. Second, a filter may be used prior to the
  impingers if the exhaust gas stream is expected to
  contain high concentrations of particulate matter.


• Analysis, including calibration, is also essentially
  the same as for Method 101 except for modifica-
  tions related to the change from ICl to KMnO 4
  as the oxidizing agent. In this case, the reduc-
  ing solution is an acidic solution of SnCl 2 , as in
  Method 101 plus sodium chloride hydroxylamine.
  The rest of the procedure is generally the same.

As for Method 101, the EPA Method 101A write-up should

be read in detail, and the method should be attempted only

by experienced personnel.

Test Method 102

The Method 102 is used to determine the emissions of par-

ticulate and gaseous mercury (Hg) when the gas stream

is predominantly hydrogen. Such streams are common at

chlor-alkali facilities that produce chlorine gas from salt

in mercury-based galvanic cells. The equipment, proce-

dures, and calculations are identical to those employed in

Method 101 except for special safety precautions related to

the flammability and explosiveness of hydrogen streams or

related to hydrogen’s low molecular weight.

For example, probe heaters, fans, and timers are used.

Also, venting provisions are more elaborate. Finally, meter

box calibrations must be performed with hydrogen or other

special gases.

As with all other procedures, the EPA Method should be

read in detail and attempted only by trained personnel using

proper equipment. This is even more important than normal

because of the serious risk of explosion.

Test Method 103

Test Method 103 is used as a screening method for determin-

ing approximate emissions of beryllium (Be). The Method has

not been extensively verified and is generally used to produce

order to magnitude estimates. If the results of a Method 103

test show the Be emissions to be within a factor of 10 or so

of the level of interest (such as a regulatory emission stan-

dard), the test would normally be repeated using Method 104,

which is much more reliable, if more expensive.

Method 103 uses a rough isokinetic sampling procedure,

in which a sample probe is placed at only three locations

along a stack diameter. The sample train consists of a nozzle

and probe connected to a filter and a meter-pump system. No

impingers are used.

Sample site location and train operation are the same

as for Method 5 except, of course, for the reduction in the

number of points and the absence of impingers. Points are

chosen at 25, 50, and 75 percent of the stack diameter at

the selected location. Sample recovery with acetone is also

essentially the same.

Test Method 104

Test Method 104 is used to measure beryllium (Be) emis-

sions at Be extraction plants, machine shops, ceramic

plants, etc. The gas stream is extracted from the stack iso-

kinetically using a Method 5 sampling train and Method 5

calibration and sampling procedures with a few minor

exceptions. The sample is also recovered according the Test

Method 5. The sample is then digested in acid and analyzed

for Be by atomic adsorption spectrophotometry (AA). Once

the sample has been collected and recovered, the solution

is digested by addition of concentrated HNO 3 , heating

until light brown fumes indicate destruction of all organic

matter, cooling, and subsequent addition of concentrated

H 2 SO 4 and concentrated HClO 4. The resulting solution is

evaporated to dryness and redissolved in HCl. During this

process, extreme care must be taken to avoid emanation of

dangerous perchlorates. Therefore, all work should be done

under an appropriate hood.

Analysis is then performed using a nitrous oxide/acetylene

flame AA at 234.8 nm. If aluminum, silicon or certain other

materials may be present, interferences may exist. They can be

eliminated by following procedures cited in the Test Method.

Calibration follows the AA manufacturer’s specifications with

specific provisions for dealing with cases in which the concen-

tration of the sample is outside the normal calibration range.

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