HELP! I'M BEING HELD CAPTIVE IN A
WASTE WATER TREATMENT PLANT
LABORATORY!!
A HELPFUL GUIDE FOR IN-SERVICE
WASTEWATER ANALYSTS
1994 EDITION
BY
CHARLES FREIDLINE, Ph.D.
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION VH
KANSAS CITY, KANSAS 66115
-------
HELP! I'M BEING HELD CAPTIVE IN A
WASTE WATER TREATMENT PLANT
LABORATORY!!
A HELPFUL GUIDE FOR IN-SERVICE
WASTEWATER ANALYSTS
1994 EDITION
BY
CHARLES FREIDLINE, Ph.D.
U. S. ENVIRONMENTAL PROTECTION AGENCY
REGION VH
KANSAS CITY, KANSAS 66115
-------
CONTENTS
L INTRODUCTION
II. SOLUTIONS TO THE MOST COMMON LABORATORY PROBLEMS
A. BEING SURE
B. RECORDING AND SAVING DATA
C. SAMPLE HANDLING
D. ANALYTICAL BALANCE TECHNIQUE
E. TOTAL SUSPENDED SOLIDS (NON-FILTERABLE SOLIDS)
F. pH MEASUREMENT
G. PIPETTING ERRORS
H. DISSOLVED OXYGEN METER CALIBRATION
I. AMMONIA-NITROGEN TEST
J. SAMPLING
III. HOW TO BE SURE YOUR ANALYTICAL RESULTS ARE CORRECT
A. THE GENERAL IDEA
(1) Run a Blank
(2) Run Duplicates
(3) Run a Standard
(4) Run a Spiked Sample
B. HOW IT CAN BE DONE
(1) Dissolved Oxygen (D.O)
(a) Meter and Probe
(b) Winkler Method
(2) Biochemical Oxygen Demand (BOD)
(a) Introduction
(b) Preparation of Glucose-Glutamic Acid Standard
(c) Analysis of the Standard
(d) Seeding BOD Samples
(e) Analysis of Spiked Samples
(3) pH Measurement
(4) Suspended Solids
(5) Ammonia-Nitrogen
-------
(a) General Principles
(b) Preparation of the Standard Solutions
(c) Using the Standards
(6) Oil and Grease
(a) Preparation of Standard Oil Mixture
(b) Preparation of Stock Oil in Water Solution
(c) Standard of Spiked Sample for Analysis
IV. PIPET TECHNIQUE
A. INTRODUCTION
B. GENERAL TECHNIQUES
C. SPECIFIC TYPES OF PIPETS AND THEIR USE
APPENDIX A: NOTES TO'MATHEMATICIANS AND CHEMISTS
APPENDIX B: SAMPLE BENCH SHEET
APPENDIX C: CURRENT EPA APPROVED METHODS FOR SELECTED COMMON
ANALYTES, 40CFR 136.3
-------
I. INTRODUCTION
In the course of doing laboratory inspections of permittees and contract laboratories
throughout Environmental Protection Agency (EPA), Region VII, I have noticed that there
are some technique errors which occur again and again in the laboratories visited. These
errors significantly affect the result of analyses reported on Discharge Monitoring Reports.
Many of you that I have visited have expressed a desire for help. You feel trapped with no
easy way to find out what your problems are, much less how to solve them. This paper
offers help with some of the most common errors and points of confusion, hopefully in
simple terms.
For certain topics a somewhat more detailed discussion is given in later sections. Since
about 90 percent of permittees are doing only analyses for DO, BOD5, total suspended
solids, pH, and ammonia nitrogen, specific comments here mostly concern these parameters.
However, many of the techniques discussed apply to other analyses too, including even the
preparation of samples and standards for analysis of metals by atomic absorption
spectrophotometry or inductively coupled atomic plasma emission.
Please take the time to thoroughly read this guide, asking yourself, "Am I doing these
procedures correctly?" If you find you have some of the problems listed here, you are not
alone, as these are common problems. Please work on the solutions to any problems you
may have so that you can have renewed confidence in your results.
You should pay close attention to Section HI and start now to set up a program of
systematic checks on the reliability of your analyses.
In the 13 years since I wrote the first edition of this booklet, the same year EPA
started the DMR-QA Studies, the quality of analyses in Region VII have improved
dramatically. This is a tribute to your capabilities and cooperation!
II. SOLUTIONS TO THE MOST COMMON LABORATORY PROBLEMS IN REGION
VII (AND ANY OTHER REGION)
A. BEING SURE
PROBLEM: Not being sure your analyses are correct.
SOLUTION: Set up a regular program to be sure your analytical results are
correct. Being sure (quality assurance) is discussed in section
III of this "Guide".
B. RECORDING AND SAVING DATA
PROBLEM: Inadequate recording of primary data and associated
information such as the time the sample was collected and time
the analysis was run.
-------
SOLUTION: Prepare a bench sheet(s) (see Appendix B for an example) for
your facility and use it rigorously, recording all the information.
It is particularly important to record such data as:
1. Weight of the filter pad or crucible empty and after
the solids are collected, and volume filtered (TSS).
2. Initial and final dissolved oxygen values, volume of
sample used (BOD).
3. Values for any control samples used for quality
assurance (making sure).
A sample bench sheet will be found in Appendix B. If more
room is needed, each type of analysis can be expanded to a full
page, or multiple pages can be used. Obviously, similar bench
sheets can be constructed for ANY analysis. If control samples
are used, they can be given a permanent place on the bench
sheet. Method references should be to the method YOU are
using. In the example, the most recent Edition of Standard
Methods (18th) is referenced, and the page and procedure
numbers are somewhat different from earlier editions.
SAMPLE HANDLING
PROBLEM: Not shaking a sample adequately just before measuring out a
part of your sample (EXTREMELY important for suspended
solids and BOD analyses).
SOLUTION: Get into the habit of vigorously shaking or stirring the sample
immediately before taking a portion for analysis. This is critical
for suspended solids analysis because settling of the solids can
cause gross errors. The suspended solids sample must be
measured out rapidly immediately after vigorously shaking or
stirring to prevent settling. Shaking is also very important for
the sample taken for BOD analysis and valuable for most other
analyses EXCEPT dissolved oxygen. When pipetting is needed,
continuously stir the sample with a magnetic stirrer or the pipet
after shaking.
-------
I Think It Means To Shake
The Sample. Bill!
D. ANALYTICAL BALANCE TECHNIQUE
(1) PROBLEM: Balance does not have adequate sensitivity for the job.
SOLUTION: Suspended solids and Oil and Grease analyses require a
sensitivity and accuracy of 0.0001 grams (0.1 mg) for the
normal size samples. Buy the proper balance!
(2) PROBLEM: Not routinely checking the balance zero.
SOLUTION: Make it a habit to check the balance zero before each
series of weighings. Balance zero can change rapidly with
changes in room temperatures, or if the balance is moved
or bumped. Balance zero is also a check to be sure the
balance is working properly. If it will not zero, check to
see that weight dials and vernier are at zero, the balance
level (make sure the bubble is in the center of the bubble
level) and the weighing pan clean. If your balance has a
taring feature, be sure you have really explored the entire
range of the zero knob. If it still will not zero, the
balance repairman should be called.
(3) PROBLEM: Weighing chamber not clean
SOLUTION: Chemicals should be weighed only in solid containers,
such as beakers. A filter pad should be supported by a
planchet (aluminum dish) or other container. A camel's
-------
hair brush can be used to clean up any solids spilled in
the balance. The pan can be removed and the chamber
washed and dried using paper towels, if needed. Dirt or
chemicals in the weighing chamber can cause
contamination and apparent weight changes of your
sample as well as corrosion of your very expensive
balance.
(4) PROBLEM: Dirty Pan
SOLUTION: Loose solids can be brushed off with a camel's hair .
brush. If necessary, the pan can be removed, washed,
rinsed with distilled water and dried thoroughly. Prevent
future problems by practicing good weighing techniques
[see (3)]. Dirt on a pan is a serious problem and can
cause erratic weighings at the milligram level due to dirt
falling off or sticking to the weighing container. Be sure
any surfaces you lay your weighing container on are dust
free.
(5) PROBLEM: Objects to be weighed are handled directly.
Small amounts of grease, moisture or salt transferred from your fingers,
can add up to 0.1 mg quantities.
SOLUTION: Use strips of lintless paper, clean tongs or forceps to
handle objects to be weighed on the analytical balance.
E. TOTAL SUSPENDED SOLIDS
(1) PROBLEM: Filter discs not prewashed to remove soluble impurities
and lose fibers.
SOLUTION: The discs should be put into Gooch crucibles or into the
filter holder and rinsed three times with distilled water,
while pulling vacuum. Be careful not to tear the disc
while rinsing or transferring.
(2) PROBLEM: Filter discs not completely dried.
SOLUTION: The prewashed discs, and the solids and discs after
filtering the sample are to be dried at 103-105°C until two
successive drying periods give weights that agree within
0.5 mg. In other words, both the tare and gross weights
-------
must be "constant weights" to ensure that all water is
removed.
(3) PROBLEM: Filter discs from a membrane filter holder or Buchner
funnel are taken off and put directly on racks in drying
oven. (The disc often sticks to the hot racks, and fiber is
lost when it is pulled loose, changing the weight. Also,
solids are easily lost when the disc is not supported).
SOLUTION: An aluminum weighing dish or Planchet should be
weighed with the filter disc and used as a support for it
in all operations except the actual filtration. If you are
using filtering (Gooch) crucibles, these supply the needed
support.
(4) PROBLEM: Incorrect filter disc
SOLUTION: Use a 0.45 fim porosity glass fiber filter disc such as
Millipore AP-40, Reeves Angel 934AH, Gelman Type A/E,
or equivalent.
CAUTION: RIDDLE
QUESTION: What kind of solids analysis do you do on those Performance
Evaluation samples that EPA sends you where they know the right
answer?
ANSWER: Totally suspenseful solids!
F. pH MEASUREMENT
(1) PROBLEM: Not standardizing often enough.
SOLUTION: The pH meter should be standardized at least once every day of
use. This should be done more often if many samples are run,
or considerable time passes between uses. On some instruments
the standardize knob is called "calibrate". Check your
instrument manual if your instrument is confusing.
(2) PROBLEM: Not standardizing properly with TWO buffers and then using a
third buffer as a control check.
-------
SOLUTION: Start by adjusting the standardize knob (called "calibrate" on
some instruments) with a pH=7 buffer. Each day of use, the
slope or calibrate function (often built into temperature
compensator, see your instrument manual) on the meter should
also be set using a second buffer (above pH = 7.00 if the
samples are likely to fall in that range, or below pH = 7.00 if
the samples are more likely to fall in that range). A third buffer
(usually about pH=4 or 10) is then used to check the
functioning of the meter. If your meter has an automatic
temperature compensator probe, it should be adjusted whenever
the slope adjustment is made. .
The pH meter should now be put in the "read pH" mode and a
pH=10.0 buffer should read 9.9 to 10.1 (if you have calibrated
with pH = 7.0 and pH = 4.0 buffers). If yours reads that close,
everything is working correctly.
For digital meters, follow manufacturers instructions for "Two-
buffer calibration".
(3) PROBLEM: Not rinsing the electrode(s) before each measurement.
SOLUTION: The electrode(s) must be rinsed thoroughly with distilled water
(a squirt bottle is useful) before they are inserted into each
sample. This is especially critical at the beginning of a series of
measurements after the electrodes have been stored in buffer, or
calibrated with buffer. Just a drop of buffer solution can greatly
alter the pH of an unbuffered sample!
G. PIPETTING ERRORS
(1) PROBLEM: Incorrect use of your pipet.
SOLUTION: There are several types of pipets in common use. The
identification and use of each type is given in Section IV.
Familiarize yourself with the procedures for the pipets you use.
(2) PROBLEM: Mouth pipetting (or starting siphons with the mouth)
SOLUTION: Use a pipet bulb or filler. Mouth pipetting is a serious safety
problem in any laboratory situation due to toricity,
corrosiveness, etc. In the wastewater analysis laboratory it also
exposes you to water-borne pathogens that can make you sick.
Exposure can occur even if you do not get the liquid in your
mouth. An analyst at a treatment plant I recently visited was
just recovering from Shigella, a water-borne disease. Generally
good hygiene (washing hands, keeping laboratory items and food
-------
separate, not smoking or eating in the laboratory, and using
bulbs) is an occupational necessity.
(3) PROBLEM: Dipping pipets into standard solutions.
SOLUTION: The solution should be shaken well and poured into a clean, dry
beaker. The pipet can be dipped into the beaker of solution,
rinsed three times by pulling a small amount into the pipet and
using it to rinse the walls, each time discarding the rinse
solution to waste. Then the pipet is filled with standard from
the beaker, the liquid meniscus adjusted to the mark, and the .
liquid dispensed. Remaining standard in the beaker is
discarded when all pipetting is finished, NEVER returned to the
stock bottle. Dipping the pipet into the standard solution can
cause both dilution and contamination. These effects are
cumulative and can cause significant errors.
(4) PROBLEM: Dipping contaminated pipets into non-standardized stock
solutions (such as manganous sulfate, sulfuric acid, etc.)
SOLUTION: In general, it is best never to dip a pipet into the stock bottle of
any solution. The same technique suggested for standard
solutions can be used, although it is inconvenient. More
practical approaches are:
(a) Use separate small dropper bottles with approximate
calibration marks on the droppers to dispense the
appropriate amounts. These solution volumes do not
need to be exact. The dropper bottles are refilled from
the stock bottles.
(b) Use separate clean pipets in each stock bottle (less
desirable).
(c) Use automatic pipets or burets for each solution (a
very expensive approach). The point of each of these
techniques is to avoid contamination, especially over a
period of time.
For many reagents, "powder pillows" with premeasured amounts of the solids are
available. These can solve the contamination problem and have much better shelf
lives than solutions. Be sure the solids completely dissolve in the solution.
H. DISSOLVED OXYGEN METER CALD3RATION
(1). PROBLEM: Dissolved oxygen meter not calibrated properly
10
-------
SOLUTION: The preferred method for calibration is to place the probe
in a BOD bottle of aerated nutrient water matched to one'
standardized using a Winkler titration. The calibration
knob is used to set the meter on the value of the oxygen
concentration determined by the careful titration.
There are two objections to the air calibration method often used:
(a) It uses different conditions than the sample measurement
(b) It does not in practice agree well with the Winkler method. Air
calibration is not forbidden in the EPA methods approvals in 40 CFR
136, but I would encourage you to use the Winkler Method for
calibration. If you do use air calibration, it is essential membranes be
kept fresh, as the difference between the methods becomes greatest with
older membranes.
The "saturated oxygen method" is rarely used because it suffers from the difficulty of
achieving true saturation.
(2). PROBLEM: Not matching the pairs of bottles of
dissolved oxygen used in the Winkler titration adequately to be certain they
are the same.
SOLUTION: Nutrient water is best added through a siphon
hose with a glass tube long enough to reach the bottom of the bottle. Fill
from the bottom up, slowly lifting the tube while keeping it under water. The
procedure is important whether you are just matching two bottles to calibrate
a D.O. meter, or if you are doing all your analyses by the Winkler method.
DO A DO
-WfNKLER !!:
L AMMONIA-NITROGEN TEST
(1) PROBLEM: The sample is not being pre-distilled
11
-------
SOLUTION: EPA rules state that wastewater samples for ammonia
analysis must be predistilled. This removes many of the
impurities present in wastewater and gives a reasonably
pure ammonia solution. For distillation, a pH=9.5
borate buffer is added to the sample to release the
ammonia. The ammonia (a volatile base) is distilled into
boric acid which reacts with the ammonia to make it into
the ammonium ion (no longer volatile). The finish of the
analysis can be done by any of the following:
(a) Nessler reaction, color readout on colorimeter or
spectrophotometer.
(b) Titration of the ammonium borate with acid
(acidimetric titration).
(c) Use of the ammonia electrode.
If you can prove by doing the analysis by the Nessler procedure or the ammonia
electrode with and without distillation over an extended period of time that you can
get the same results under all conditions with your samples, you can do it without
distillation. The acidimetric titration always requires distillation. Be sure to keep
all your data on hand to prove it to any EPA/State inspector who might ask to see it.
If you cannot produce the information showing the distilled values are the same as
the non-distilled, it is not legal to skip the distillation step. Domestic wastewater is
NOT a good candidate for an exception!
(2) PROBLEM: Using a visual comparometer (color wheel) to read out
the Nessler color.
SOLUTION: A spectrophotometer or colorimeter must be used for the
readout. These instruments are capable of the necessary
wavelength selectivity to avoid including impurities in the
measurement. It also avoids the subjective color
matching which can cause significant disagreement in
concentration between two observers. Color wheels are
not acceptable for other wastewater analyses either.
J. SAMPLING
(1) PROBLEM: Not using the sampling method called for in your permit.
SOLUTION: Check your permit for the type of sampling required for each
parameter. The most common types of sampling methods are:
(a) 24-hour composite - Samples must be taken at least once every four
hours around the clock. One-shift plants with this requirement either
12
-------
need a man to come out and take night samples or need to obtain an
automatic sampler. The best practice for collecting composite samples
is to purchase and use an automatic sampler. These make the job
easier and give a sample more representative of your discharge.
Generally, night samples will be more likely to be within permit limits
than day samples, and it is to your advantage to include them!
(b) Grab samples - single sample taken directly. Note that pH, dissolved
oxygen and temperature are always run on a grab sample.
(2) PROBLEM: Not icing or refrigerating samples that are not analyzed
immediately, especially composites.
SOLUTION: Preservation of a sample requires that it be kept cold (4°C,
40°F) until analyzed. In winter this is usually automatic for
compositors kept outside. When daytime temperatures get above
about 50°F (10°C), or water temperatures get above 5°C, it is
time to ice or refrigerate your sample.
(3) PROBLEM: Collecting samples at locations that do not give a true picture of
your effluent discharge.
SOLUTION: Effluent samples must be obtained at a point representative of
the water actually being discharged. Normally this should be
just after the effluent has passed through a discharge weir or
flume while the water is moving rapidly and is well-mixed.
Sampling hoses lying on the bottom of still areas before or after
discharge are not likely to represent the true effluent.
WASTEWATER TREATMENT PLANTS HAVE NOW BEEN AROUND FOR MOST OF
A CENTURY. I PREDICT THE RISE OF NEW BIRD SPECIES TO FIND THEIR
SPECIAL NICHES AROUND WASTEWATER TREATMENT PLANTS. SOME
FUTURE "GUIDE TO BIRDS" MAY DESCRIBE THEM THIS WAY:
1. BROWN SLUDGIN: This species is completely brown and individuals are known
best for their habit of diving head-first into activated sludge tanks. Some ornithologists,
after observing them following a heavy rain, believe their natural color may not really be
brown.
2. FILTER FLYCATCHER: Trickling filters have long been known as the habitat of
filter flies. These birds have adapted to using filter flies as an almost exclusive diet.
To encourage the habits of these useful birds, ecologically minded operators will be sure
that any covered filter domes have access holes large enough for them to enter, but
small enough to exclude their predators (3-4"in diameter).
13
-------
III. HOW TO BE SURE YOUR ANALYTICAL RESULTS ARE CORRECT
A. The General Idea
All of us like to know we are right. It is especially important to know and be able to
prove you are right when doing analyses that affect your permit compliance status. At
present, very few labs have established any routine method of being sure. Words that are
frequently used for a program of being sure are:
(1) Quality Assurance is a regular program using the analyses of known
amounts of a substance to BE SURE your analyses give good results,
(2) Quality Control is the daily use of proper techniques, equipment
calibrations, etc., to ensure good results
A simple detailed quality assurance program geared to small laboratories doing
NPDES tests is not easy to find. The following discussion is intended to give you enough
detail so you can set up a routine quality assurance program for your laboratory. There are
four general procedures that you should start doing regularly for each parameter you
analyze:
(a) Run a blank; A blank is usually distilled water carried through all the
steps of your analysis just like it was a sample. Clearly, the result should be
very close to zero. A significant positive result tells you there is a problem
with the water, reagents or technique. Not all parameters have blanks, e.g.
pH.
(b) Run at least duplicate (two or more of each) samples on all analyses
required by your permit; The analysis of duplicate samples gives an idea of
how consistent your results are. The sample is analyzed at least twice. If
everything is being done the same way each time, the results should be
reasonably close to each other. If you are doing large numbers of samples on
the same day, at least one of every ten should be run in duplicate. If your
sample load is not large, ALL samples should be run in duplicate.
(c) Run a standard (preferably in duplicate); A standard is a carefully
measured amount of the material for analysis dissolved in an accurately
known volume of solution. This solution is analyzed just like a sample, and
the results obtained are compared with the known concentration. Known
samples for analysis can be occasionally ordered from EPA. Please limit your
requests to one or two sets of samples each year. Call or write:
Michelle Shirley
The Bionetics Corporation
16 Triangle Dr.
Cincinatti, OH 45246
(513) 771-0448
14
-------
Please specify which analyses you do. Several companies now sell similar
standards, and some have routine programs to check your results.
These samples are not a substitute for your own program for being sure.
(d) Run a spiked sample along with the sample: Have you heard of
"spiking the punch?" Spiking a sample is very similar, except that one
carefully measures volume of the spiking standard and the sample so the
amount of standard added to the sample is accurately known. Then both the
sample and the spiked sample are analyzed. The DIFFERENCE between
them should equal the concentration calculated for the;spiking standard from
the total volume of sample used. .
SPIKING THE PUNCH
B. HOW IT CAN BE DONE
(1) DISSOLVED OXYGEN (D.O):
SPIKING THE SAMPLE
(a) Meter and Probe: The D.O. Meter should be calibrated in oxygenated
water analyzed for D.O. by the Winkler method. Approximate checks
can be made by then:
1 Measuring the oxygen in air and comparing the meter reading
with the concentration of oxygen from the manufacturer's tables
for the barometric pressure in your laboratory. These will differ
some, but will normally fall within about 0.2 - 0.4 ppm (mg/L)
from the Winkler standardized readings if your membranes are
fresh. See the manufacturer's manual for measurement
conditions.
2 Measuring the oxygen in water carefully saturated with oxygen
and comparing the readings with the theoretical solubility of
oxygen in water at that temperature. This method depends on
15
-------
reaching complete saturation. A reasonable way to prepare a
saturated oxygen in water solution is to take water a few degrees
cooler than 20 °C (for example, 15°C). Bubble air through it for
at least 15 minutes or shake it in an oversized container for at
least two minutes, then let it stand in the 20°C incubator long
enough to reach a uniform temperature. The solution will now
have too much oxygen in it for the temperature of 20°C. Shake
it vigorously for two minutes, releasing the pressure occasionally
to remove the excess oxygen. The concentration of oxygen in
water at 20°C is given in Standard Methods, 18th Ed., p. 4-101t
under method 4500-O-C.
Using the unconnected barometric pressure (just as it is read off of the barometer),
calculate the solubility (see note below table) of oxygen at the temperature of your nutrient
water. This concentration can be used to check the D.O. Meter value, and one can also
titrate the saturated solution using the Winkler Method. All three values should agree
within ± 0.4 mg/L if all the procedures have been done adequately.
(b) Winkler Method; The saturation method (B.I, a.2) just given can be
used as an approximate check of the Winkler Method.
It is important that the standard titrant (sodium thiosulfate) be standardized against
primary standard potassium biniodate or potassium iodate (See Standard Methods, 18th
Ed., method 4500-O-C, p 4-100.). When preserved with sodium hydroxide the sodium
thiosulfate solution is fairly stable. It should be re-standardized about once per three
months. Phenylarsine oxide (PAO) is more stable, but should be checked occasionally.
CAUTION: ORGANIC ARSENIC COMPOUNDS (such as PAO) HAVE HIGH
TOXICITY. WASH HANDS, DISPOSE OF PROPERLY, '
ANOTHER BIRD:
3. LAGLOON: (can be pronounced either lag'Ioon or la gloon') These algae
feeders can be see floating gracefully on aerated lagoons, their distinctly green bottom
half is believed to be the best identification marking. Their rather eerie call sounds
remarkably like the whine of an aeration pump, and ends with a distinct gurgling sound.
16
-------
(2) BIOCHEMICAL OXYGEN DEMAND (BOD5)
(a) Introduction; The use of a "standard" mixture of glucose-glutamic acid for a
standard check is suggested in Standard Methods, 18th Edition, Method
5210B, page 5-3. It is necessary to seed these standard samples to provide
the micro-organisms necessary for the BOD, so the procedure given will
include the seeding process.
A simple way to use the "standard" mixture is as a spiking solution in the sample. In this
way the sample provides an accurately known seed.
(b) Preparation of Glucose-Glutamic Acid "Standard"; Dry some reagent grade
glucose and reagent grade glutamic acid for one hour at 103°C. Weigh 150.0
mg (.ISOOg) of each (use beakers as weighing containers) and transfer them
carefully through a funnel into a 1 liter volumetric flask. Rinse the beaker
and funnel well with distilled water to get all the solids into the flask. Add
two pellets of sodium hydroxide and shake to dissolve. Dilute carefully to the
CAUTION; Sodium hydroxide BURNS the skini!!
Use gloves or forceps to handle.
mark. After mixing, transfer to a one-liter bottle (preferably brown) for
storage. This solution will keep several months in the refrigerator. (Date it.
Remake after one year or when bad results are obtained, whichever comes
first.)
(c) Analysis of the Standard; A BOD can be run directly on 5.00 mL (volumetric
pipet) of this solution as suggested in Standard Methods, 18th Ed., Method
5210B, page 5-3. Expected results are discussed in BOD Example 1. It is
necessary to seed the sample and run a BOD on the seed.
(d) Seeding BOD Samples; Choose as seed a fairly low BOD sample such as
river water, unchlorinated effluent from your plant, or filtered raw influent.
The point is to choose a seed with plenty of bacteria but not a high BOD
value.
Add about 3.0 mL seed* to each 300 mL BOD bottle. An alternative is to add
10.0 mL seed solution for each liter of dilution water and then use it all
within 30 minutes after seeding. Make up the dilutions of the standard
using the seeded dilution water. The BOD of the solution used as seed should
be determined the same way you usually determine BOD on similar samples
and a seed blank correction used that is calculated from the BOD of the seed. I
The calculation section below will illustrate this.
17
-------
You may need to use more seed if your values do not agree well with each
other. If your seed has too high a BOD, you may need to use less.
Generally use about 1/10 of your lowest seed dilution WHICH GIVES A
USEABLE DEPLETION (greater than 2 mg/L change in D.O.) to seed.
EXAMPLE: if 5% (15 mL), 10% (30 mL) and 15% (45mL) are useable
dilutions to calculate the seed BOD, 1.5 mL (or round to 2 mL) would be
a good amount to add to 300 mL of the sample to be seeded, or 6 mL to
each liter of nutrient water.
BIOCHEMICAL OXYGEN DEMAND CALCULATIONS FOR SEEDED SAMPLES:
(a) Calculation of the seed blank correction:
(BOD J x (V J
B = - - «££ — '"* = SEED BLANK CORRECTION
WHERE:
BOD of seed you determined by your usual method
Volume of seed solution added to sample or nutrient water, mL
VMln = Total volume of sample or nutrient water made up, mL
B = Seed blank correction
(b) Calculation of the BOD of the standard (or any seeded sample);
(Dl -D2 - B) x
WHERE:
D! = Initial D.O. of diluted sample, mg/L
D2 = Final D.O. of incubated diluted sample, mg/L
vbottie = Capacity of BOD bottle (or cylinder, if used), mL
18
-------
'std
Volume of standard (or any seeded sample) added to
BOD bottle (or cylinder), mL.
BOD EXAMPLE NUMBER 1
TABLE 1-A: BOD of Your Sample Used For Seed
Seed Solution (Plant Effluent, use your normal BOD Procedure)
v
T sample
10
50
100
DI
7.6
7.4
12
D2
7.0
4.8
2.3
DrD2
0.6
2.6
4.9
BODsecd
Too little D.O.
change +
15.6
14.7
NOTE: VALID SAMPLES MUST DEPLETE AT LEAST 2 mg/L, AND THE FINAL D.O.
MUST BE AT LEAST 1 mg/L.
Average seed BOD = 15.1 (Avg. of 15.6 and 14.7).
a. A 2.0 liter (2000 mL)* bottle of nutrient water was seeded by adding 20.0 mL of this
effluent.
b. A series of three 300 mL BOD bottles were set by adding 5.0 mL of standard glucose-
glutamic acid solution to each and filling with this seeded nutrient water
c. The results obtained are tabulated below:
TABLE 1-B: Data and Calculation of the BOD ofthe Standard
vstd
5.0
5.0
5.0
DI
7.6
7.5
7.5
D2
3.7
4.0
3.9
DrD2
3.9
3.5
3.6
BODstd
225
201
207
Deviation
from
average
14
10
4
Average BOD = 211 Average Deviation = 9
19
-------
How the calculations were done;
Seed Blank Correction = B
B x (VMJ 15.1 x 20.0
V ~ 2000
For each bottle of standard incubated in this example;
(/>! - D2 -0.15) x (300)
M ~ 5^0
(where B = 0.15)
BOD EXAMPLE CALCULATION:
BODstdl - <7.6-3.7-0.15) x (300) = ^(£ilst bottle)
The AVERAGE of the BOD's of the standard is found by adding up all the BODstd values
and dividing by the number of values as follows for our EXAMPLE 1:
Average BOD,, - . m mg/L
The AVERAGE DEVIATION is calculated by adding up the ABSOLUTE differences
(subtract small number from the larger number) between the average BOD and each
individual value:
20
-------
AVGDEV = C25-211)+(211-201)+(211-207) - 9 mg,L
Notice that the average deviation (9 mg/L) in our example is close to the standard
deviation (10 mg/L) obtained for a single laboratory long-term study listed in 5210B on
page 5-6 in Standard Methods, 18th Edition. While the standard deviation is a better
statistical indicator, it is more complicated, but the average deviation gives a reasonable
approximation. Also, the average BOD value obtained in this single laboratory study was
204, within 10 of our value (211).
In a large interlaboratory study with all kinds of conditions, the average BOD value and
standard deviation was 198 ± 30.5. If your values for the glutamic acid-glucose standard
lie within that range, your values are probably o.k.
NOTE TO MATHEMATICIANS AND CHEMISTS: See Appendix A for a discussion of
standard deviation. In this example, standard deviation was 12.5 mg/L.
(c) Analysis of Spiked Samples;
Spiked samples have a known amount of the glucose-glutamic acid standard added
to a regular BOD sample. The BODs of the sample by itself and the spiked sample are
determined, and the DIFFERENCE between them is the BOD of the glucose-glutamic acid
standard. This is a good test of your techniques as well as the quality of the seed.
21
-------
BOD EXAMPLE 2: SPIKING A PLANT SAMPLE
Spiked Sample Results for a Trickling Filter
Plant Effluent with Approximately BOD = 20 mg/L
VOLUME
SAMPLE
0
30
45
60
30
45
60
VOLUME
STAND
0
0
0
0
3.0
3.0
3.0
INIT DO
D,
8.8
8.7
8.5
8.3
8.7
8.5
8.3
FIN DO
D,
8.8
6.8
5.4
4.3
4.6
3.3
2.0
*ADO
SAMPLE
0
1.9
3.1
4.0
ADO
MIXTURE
4.1
5.2
6.3
ADO STD
SPIKE
4.1-1.9=
2.2
5.2-3.1=
2.1
6.3-4.0=
2.3
BOD
SAMPLE
0
AD<2
21
20
BOD STD
SPIKE
• '•
220
210
230
* NOTE: A means "difference," or one subtracted from the other.
How the calculations were done:
This example assumes 300 mL BOD bottles. For another size, substitute the actual volume
for "300".
BOD
uunplt
BOD.
300(ADQJ
rad
Find the average of the BODs of the standard by adding up all the BODsstd and dividing by
the number of BODsstd.
Average BODgtd = (220*21Q*230> - 220 mg/L
22
-------
As a test of the agreement between your values the average deviation can again be
calculated as we did in the previous example:
. n . . (220-220)+(220-210)+(230-220) - „„
Average Deviation = — — —= 7 mg/L
w
Notice that our values of 220 mg/L ± 7 adequately agree with the value of 198 ± 30 for the
pure spiking standard. In Standard Methods, 14th edition, page 548 a table suggested
spiked trickling filter samples would run higher, to about 225, but would give good precision
(small standard deviation).
Show Me Your
Flow Measuring
Device.
There It Is,
Ever Since The Last Flood
We've Had A Partial Flume.
(4) pH MEASUREMENT
The three buffer procedure outlined in the "Common Problems" section is both a
calibration and quality assurance procedure. Be sure to RECORD the true and
measured value of the pH of the third buffer.
Additional buffers can be used as further checks.
(5) TOTAL SUSPENDED SOLIDS-fNON-FILTERABLE RESIDUE)
A perfect standard for the suspended solids in wastewater is difficult to find.
Possible standards must have the following characteristics:
a. Be insoluble in water
b. Not pass through the filter medium
c. Disperse well in water
d. Not be volatile at 105°C
e. Have a density not too much higher than water
23
-------
f. Be wettable by water
Because of the difficulty in finding and preparing such substances, the use of
prepared quality assurance samples from EPA or a commercial standards company
like SPEX or Environmental Research Associates (ERA) is recommended. EPA
standards can be ordered from:
Michelle Shirley
The Bionetics Corporation
16 Triangle Dr.
Cincinatti, OH 45146 '•'.'.-
(513) 771-0448
Follow the instructions sent with the samples for preparing the standard solution, and
analyze it by your usual procedure for suspended solids. Your results should be
within about 10% of the known value included with the sample. Good analyses are
generally low; high values suggest problems with the weighings or inadequate drying.
(6) AMMONIA-NITROGEN
(a) General Principles
Ammonium Chloride is an ideal standard for the ammonia-nitrogen test. For
accuracy, it is usually best to make a solution more concentrated than desired
and dilute it accurately using a volumetric pipet and a volumetric flask. For
example, if your samples run in the 1.0 - 10.0 mg/L range, prepare a stock
solution of about 100 mg/L nitrogen using ammonium chloride. Dilutions of
this solution can then be used both as a standard to run through the entire
procedure, and as calibration standards for a spectrophotometer if the Nessler
procedure is used. The EPA "Methods For Chemical Analysis of Water and
Wastes" (1979) gives directions for a specific stock solution and a series of
calibration standards that can be made from it, or you can use the series given
(b) Preparation of the Standard Solutions
To make up your own series with directly stated concentrations, do the
following:
24
-------
General Procedure
Specific Example
Decide on stock solution
concentration (about 10 times your
sample concentration).
Multiply concentration of
Nitrogen desired by 3.821 to get the
weight of ammonium chloride
needed per liter.
Move decimal point three places
left to get grams.
Weigh out that many grams of
ammonium chloride.
Using distilled water in a wash
bottle, rinse all the ammonium
chloride into a 1.000 liter
volumetric flask.
Add enough water to dissolve all
the solid. Then dilute to the mark
and mix for two minutes by
inverting the flask every few
seconds.
This solution is your stock solution.
Calculate the exact concentration of
nitrogen, CN, by:
If samples run about 5 mg/L Nitrogen,
make stock 50 mg/L Nitrogen
Ammonium chloride = 3.821 x 50 mg/L
= 191.0 mg/L
191.0 = .1910 g.
Weigh out .1910 grams ammonium
chloride in a beaker on the analytical
balance.
Wash all .1910 grams ammonium chloride
from beaker into 1.000 liter volumetric
flask
Wt. Amman Chlorjmg)
(3.821)(Vo/ [L])
191.0 mg
(3.831)(1.00[L]>
8. Solutions for analysis are made by
diluting the stock solution using a
pipet and volumetric flask.
'ltd
10.0 mL of the above stock are pipetted
into a 100.0 mL volumetric flask, diluted
to the mark, and mixed well.
= (10.0 mL)(50.0
100.0 mL
= 5.00 mg/mL ammonia-nitrogen
25
-------
(c). Using the Standards
1. As a quality assurance check standard:
The standard is analyzed just like a sample, but you know the real value.
Carry a measured amount of standard through the distillation and finish steps
just like a sample. Do not forget that the maximum ammonia-nitrogen -
concentration that can be determined directly by the Nessler Method is 2
mg/L. For greater concentrations, accurate volumetric dilution must be made
to bring the concentration into range.
2. To calibrate the spectrophotometer:
A calibration curve can be made for a spectrophotometer by diluting the stock
(or an intermediate dilution) to make a range of solutions with ammonia-
nitrogen concentrations up to 2 mg/L. These can be directly Nesslerized
without distillation.
EXAMPLE: Using the 5.00 mg/L solution prepared in the previous example, the
following dilutions can be made using pipets and volumetric flasks:
PREPARATION OF STANDARD SOLUTIONS
VOLUME 5.0 mg/L
STOCK, mL
10
20
25
30
40
VOLUMETRIC FLASK
VOLUME, mL
100.0
100.0
100.0
100.0
100.0
CONCENTRATION OF
STANDARD SOLUTION,
mg/L
0.50
1.00
1.25
1.50
2.00
Nesslerize the standards just like you would do for your samples and measure
the absorbance of each. Then prepare a graph of absorbance versus
concentration of ammonia-nitrogen. The concentration of your unknown
samples and quality assurance check standard can then be read off the graph
once you have measured their absorbance with your spectrophotometer.
26
-------
AMMONIA NITROGEN EXAMPLE:
Assume you measured the following absorbances for your Nesslerized standards and
your quality assurance check standard and your unknown sample:
CONCENTRATION OF STANDARD
0.50
1.00
1.25
1.50
2.00
QA 1.33 mg/L
UNKNOWN SAMPLE
ABSORBANCE AT 425 nm
0.152
0.301 ' : . •
0.373 . . --
0.453
0.594
0.397
0.220
600
500
400
300
200
100
The graph would be made as follows where values for the standards are shown by
circles, and the value for the sample is shown by a square. The concentration of the
Nesslerized sample would be read as 0.72mg/L.
o
.5
1.0
1.5
2.0
CONCENTRATION OF AMMONIA NITROGEN, mg/L
Note the QA sample fits the data from the standards even though it was treated like a
sample. This is a good indication your method is accurate and working. A SPIKED
sample could also be run.
27
-------
7. OIL AND GREASE
(a) Preparation of a Standard Oil Mixture;
Make a 50-50 mixture by weight of a mineral oil and vegetable oil.
Mineral Oil - from drugstore, or get a
NON-DETERGENT motor oil
Vegetable Oil - such as Wesson Oil
As an example, one could mix 10 grams of mineral oil with 10 grams of the vegetable
oil. The weights are not critical for this solution.
Standard Methods, 18th Ed, page 5-26 gives similar mixtures.
(b) Preparation of a Stock Oil in Water Solution
Weigh exactly 1.000 g (1000 mg) of the oil mixture in a 120 mL (4 Oz) or 240
mL (8 oz.) bottle. Pipet 100.0 mL distilled water into the bottle, cap and
shake vigorously to form a good emulsion. Each 1.00 mL of this solution
supplies 10.0 mg. of oil
1000 mg in . ,
£- = 10 mg/mL
100 mL
You can make the stock solution more concentrated or more dilute by weighing out
more or less oil.
For any weight of oil added to any volume of water:
No. of mg Oil = mg/mL of Oil.
No. of mL Water
(Each mL stock solution pipetted delivers this many mg oil.)
Shake the stock solution VIGOROUSLY iust before using.
NOTE TO CHEMISTS: The extra volume of oil is about .80 mL (densityoil = about .8)
and can be included in the equation above for total volume, but it is really negligible in
this analysis (<1%).
28
-------
(c) Standard or Spiked Sample for Analysis
To make a standard solution for direct analysis, measure and add 350*800 mL
distilled water (amount depends on size of your separatory funnel and normal
sample size) to an oil and grease sample bottle. Carefully pipet a definite amount of
the stock solution into the collection bottle. If you are using the stock standard from
part b), each mL of stock standard will give you 10 mg oil and grease in the volume
of water used. For any volume stock standard, 10 mg/mL X V(mL) = mg oil.
Analyze this solution and compare the amount you added with the results of your
analysis.
For a spiked sample, you measure about 350-800 mL of your effluent instead of
distilled water. Pipet the stock standard as before to prepare your spiked sample.
Now analyze separately the spiked sample and your pure effluent. The
DIFFERENCE between the results should equal the mg. of oil added from the
spiking solution.
DESCRIPTIONS OF SOME MORE NEW BIRDS:
4. DITCH DUCK: These water fowl can often be seen riding the agitation brush in
an oxidation ditch up into the air and then splashing down on the other side. There is
no evidence they feed in the oxidation ditch, and its attraction may be completely
recreational!
5. BOTTOMLESS PITABOLINK: These remarkable birds produce no effluent of
their own, completely metabolizing all their food to carbon dioxide, water and nitrogen.
Where large flocks have formed at wastewater treatment plants, suspended solids and
BOD of the plant effluents have dropped to less than 1 mg/L! Attempts are being made
to breed flocks of these useful birds for other treatment plants.
IV; PIPET TECHNIQUES
A. INTRODUCTION
There are a surprising number of pipet styles available and in use in
wastewater treatment plants. You need to be familiar with the proper use of
the kinds you have, and use them in the intended manner in order to obtain
accurate results. This section will first outline general techniques used for all
pipets,- and then will discuss the specific types of pipets.
B. GENERAL TECHNIQUES
1. Pipets are NEVER dipped into bottles of standards, and only under special
conditions into the stock bottles of other solutions, because of the danger of
contamination or dilution. After carefully shaking the bottle of stock solution,
29
-------
pour a small amount into a clean dry beaker. The pipet will be dipped into
the beaker.
2. Pipets are rinsed with the solution to be measured. Using a bulb, carefully
draw a little of the solution up into the pipet (about 10 percent of its
capacity). Hold the pipet sideways and roll it so the solution wets all the
walls. Drain the pipet into a waste container.
At this time check the wet pipet for beads of water between calibration
lines or calibration line and tip. Beads are due to grease in the pipet and
must be cleaned out of the pipet. Various cleaning solutions are available to
remove grease, and need to be used. See any chemical company catalog for
detergents or cleaning solutions that remove grease from volumetric ware.
For standards or high purity solutions, repeat the process of rinsing
with the solution to be used two more times. These additional rinses can be
omitted if your pipet was clean and DRY at the start. Any remaining solution
in the beaker is discarded, and enough fresh solution added to the beaker to
fill the pipet.
3. Pipets are filled and read while straight up and down. Using the bulb, fill
the pipet to above the appropriate mark. Remove the bulb, and using the
index finger of your major hand, leak enough air to allow the liquid to escape
until the bottom of the meniscus is on the top of the line. What you do with
the tip depends on the type of pipet (discussed below under each specific
type).
MENISCUS
What is a meniscus??
CALIBRATION
LINE
SHADOW
Put a piece of black paper (or paper blacked in with pen) behind your pipet
at the water level in the neck. The shadow will mostly disappear under these
conditions. Now move the black paper up and down. The shadow will move,
but the true meniscus will not. Bring the bottom of the meniscus down until
it just sits on top of the calibration line. If you have trouble holding the
liquid at the right place, practice with a buret first.
30
-------
SPECIFIC TYPES OF PEPETS AND THEIR USE
Volnmetric (Transfer) Pinet
a. These have a single calibration line and look like this
b. The tips are usually fine and this type of pipet should not be
used for solutions where larger floating solids must be
transferred.
c. The tip of the pipet should be held against the wall of a waste
container while bringing the meniscus down to the calibration
line.
d. After bringing to the mark, the solution is allowed to flow freely
into the container you are transferring to with the tip against
the inside wall of the container.
e. Leave the pipet tipped to the container for several seconds after
flow has stopped.
Serological. MOHR or Measuring Pipets
SERIOLOGICAL MOHR OR MEASURING PIPETS
3.
a. After bringing the meniscus to the appropriate mark, touch the
tip to the wall of a waste container.
b. Allow to drain into the container you want solution in without
touching tip to container.
c. Drain to final mark and then touch tip to inside wall of
container you want your solution in.
Serological pipet with one or two ground-glass or etched bands on
mouthpiece, or two colored bands.
Treat just like the regular Serological pipet except when it is completely
drained, blow it out with your bulb.
31
-------
4. Dual Purpose Pipets
These have separate lines for:
TD - Calibrated to deliver the stated volume. Use just like equivalent
pipets above.
TC - Calibrated to contain the stated volume. Would be more accurate
where it is necessary to wash out a pipet - such as during suspended
solids analysis where the solids sticking to side must be washed down.
I Didn't Know
The Sludge Could
Get That Activated!
The mention of brand names in this document does not imply endorsement by the U.S.
Environmental Protection Agency.
32
-------
APPENDIX A
NOTES TO MATHEMATICIANS AND CHEMISTS
1. In the standard mathematical symbolism the average BOD is:
Ex.
X = —'-
WHERE:
X = Average BOD (mean)
Xj = Individual BOD values
n = Number of BOD values
2. The average deviation is written
d =
n
The standard deviation is a better statistical indicator and is defined by the function.
s =
n -I
33
-------
APPENDIX B: SAMPLE BENCH SHEET.
TILLIBOTZAM LABORATORIES
ANALYSTS: Murgatroid Tillibotzam
Dripworth R. Wetwater
DATE & TIME SAMPLE COLLECTED:
DATE & TIME SAMPLE ANALYZED:
TSS:
BOD:
pH:
PERSON COLLECTING:
INITIALS OF ANALYST:
BIOCHEMICAL OXYGEN DEMAND-BOD OR CARBONACEOUS BOD:
METHOD REFERENCE- EPA method 410-1, Methods for Chemical Analysis of Water and Wastes, 1979. Or Standard Methods 5210, p.
5-2,18th Ed, 1992.
SAMPLE LOCATION
&/OR
CLIENT
BLANK 1
BLANK 2
QA SAMPLE
BOTTLE
NUMBER.
SAMPLE
VOLUME
-
INIT.
D.O.
FINAL
D.O.
-
CHANGE
IN D.O.
BOD
BOD = A(D.O.,mg/L)x 300mL/SAMPLE VOL(mL) = mg/L
TOTAL SUSPENDED SOUPS:
METHOD REFERENCE: EPA method 160.2, Methods for Chemical Analysis of Water and Wastes, 1979. Or Standard Methods 2540D,
p 2-54,18th Ed, 1992.
SAMPLE LOCATION
&/OR
CLIENT
SAMPLE
NUMBER
SAMPLE
VOLUME
FILTD
WTPAD
+ SOLID
WTPAD
WT. OF
SOLIDS
TSS
TSS = WT. SOLlDS(g)X(1000 mg/g x 1000 mL/L)/SAMPLE VOL(mL) = mg/L
METHOD REFERENCE: EPA method 150.1, Methods for Chemical Analysis of Water and Wastes, 1979. Or Standard Methods 4500,
p.4-65, 18th Ed., 1992.
SAMPLE LOCATION &/OR CLIENT
CONTROL BUFFER ( TRUE pH = )
PH
.
34
-------
APPENDIX C: LIST OF APPROVED INORGANIC TEST PROCEDURES FOR COMMON
ANALYTES SELECTED FROM 40CFR136.3 DATABASE, JAN, 1994
PAAMETER, UNITS AND METHOD
REFERENCE (METHOD NUMBER OR PAGE)
Std.
EPA1'" Methods ASTM USGS* Other
18th Ed.
1. Acidity, aa CaCO,, mg/L;
Slectrometric endpoint or
phenolphthalein endpoint
2. Alkalinity, as CaCO3,
tig/L:
Slectrometric or
Coiorimetric titration
to pH 4.5, manual or
automated
3. Aluminum — Total ,
mg/L; Digestion
followed by:
AA direct aspiration36
AA furnace
Inductively Coupled
Plasma/Atomic Emission
Spectrometry (ICP/AES)36
Direct Current Plasma
(DCP)36
Color imetric (Eriochrome
cyanine R)
4. Ammonia (as N), mg/L:
Manual distillation (at pH
9.5)6 followed by:
Nesslerization
Titration
Electrode
Automated phenate, or
Automated electrode
5. Arsenic — Total4,
.mg/L:.
Digestion* followed by:
AA gaseous hydride
AA furnace
ICP/AES36 or
Color imetric (SDDC)
'. Biochemical oxygen
demand (BOD5), mg/L:
Dissolved Oxygen Depletion
-2. Cadmium — Total4,
mg/L; Digestion
followed by:
AA direct aspiration36
AA furnace
ICP/AES36
DCP36
Voltametry11, or
305.1
310.1
202.1
202.2
5200.7
350.2
350.2
350.2
350.3
350.1
206.5
206.3
206.2
5200.7
206.4
405.1
213.1
213.2
5200.7
2310
B(4a)
3111 D
3113 B
3120 B
3500-A1 D
4500-NH3B
4500-NH,C
4500-NHjE
4500-NH3F
or G
4500-NH3H
314 B 4.d
3113 B
3120 B
3500-As C
5210 B
3111 B or
C
3113 B
3120 B
D1067-92
D4190-
82(88)
D1426-89(A)
D1426-89(B)
D2972-88(B)
D2972-88(C)
D2972-88(A)
D3557-90(A
or B)
/
D3557-90(D
D4190-
82(88)
D3557-90(C
1-3051-85 .
1-3520-85
1-4523-85
1-3062-85
1-3060-85
I-1578-788
1-3135-85
or
I-3136-859.
1-1472-85
Note 34.
973.49.3
973. 49. 3
Note 7.
973. 443
p.179
974. 273
p. 37
K
Note 34.
-------
Colorimetric (Dithizone)
14. Carbonaceous
biochemical oxygen demand
(CBOD5), mg/Lir:
Dissolved Oxygen Depletion
with nitrification
inhibitor
.15., Chemical oxygen demand
. (COD), ing/L; Titrimetric,
• or
Spectrophotometric, manual
or automated
16s Chloride, mg/L:
Titrimetric (silver
nitrate)
Or (Mercuric nitrate)
Colorimetric, manual or
Automated (Ferricyanide)
17. Chlorine—Total
residual, mg/L; Ti-
trimetric:
lerometric direct
letric direct
ck titration either
end-point or
DPD-FAS
Spectrophotometric, DPD
Or Electrode
18. Chromium VI dissolved,
mg/L; 0.45 micron
filtration followed by:
AA chelation-extraction or
Colorimetric
(Diphenylcarbazide)
.9. Chromium—Total4,
mg/L; Digestion4
followed by:
AA direct aspiration36
AA chelation-extraction
AA furnace
ICP/AES36
DCP36, or
Colorimetric
(Diphenylcarbazide)
;0. Cobalt—Total4,
mg/L; Digestion4
followed by:
tt.rect aspiration
EPA
1,35
410.1
410.4
325.3
325.1 01
325.2
330.1
330.3
330.2
330.4
330.5
218.4
218.1
218.3
218.2
5200.7
219.1
Std.
Methods
18th Ed.
3500-Cd D
5210 B
5220 D
4500-C1 B
4500-C1 C
4500-C1 E
4500-C1 D
4500-C1 B
4500-C1 C
4500-C1 F
4500-C1 G
3111 C
3500-Cr D
3111 B
3111 C
3113 B
3120 B
3500-Cr D
3111 B or
C
ASTM
D1252-88(B
D512-89(B)
D512-89(A)
D1253-
86(92)
D1687-92(A
D1687-92(B)
D1687-92(C
D4190-
82(88)
D3558-90(A
or B)
USGS"
1-3561-85
1-1183-85
1-1184-85
1-1187-85
1-2187-85
1-1232-85
1-1230-85
1-3236-85
1-3239-85
Other
Notes 13
or 14.
973.513
Note 16.
974.273
Note 34.
p.379.
-------
Std.
EPA1'35 Methods ASTM USGS2 Other
AA furnace
ICP/AES
DCP
12. Copper — Total*,
mg/L; Digestion*
followed by:
AA direct aspiration36
AA furnace
ICP/AES36
DCP36, or
Color imetric (Neocuproine)
•or
(Bicinchoninate)
23. Cyanide — Total, mg/L:
Manual distillation with
MgCl2 followed by
Titrimetric, or
Spectrophotometric, manual'
or
Automoted20
?4. Cyanide amenable to
chlorination, mg/L:
Manual distillation with
MgClj followed by
titnmetric or
Spectrophotometric
:5. Fluoride — Total, mg/L:
Manual distillation6
followed by
Electrode, manual or
Automated
Colorimetric (SPADNS)
Or Automated complexone or
:7. Hardness — Total, as
CaCO3, mg/L:
Automated colorimetric
Titrimetric (EDTA), or Ca
plus Mg as their
carbonates, by
inductively coupled
plasma or AA direct
aspiration. (See
Parameters 13 and 33)
8. Hydrogen ion (pH), pH
units:
Electrometric measurement,
or
Automated electrode
0. Iron — Total4, mg/L;
Digestion4 followed
219.2
5200.7
220.1
220.2
5200.7
335.3
335.3
335.1
340.2
340.1
340.3
130.1
130.2
150.1
18th Ed.
3113 B
3120 B
3111 B or
C
3113 B
3120 B
3500-Cu D
or E
4500-CN C
4500-CN D
4500-CN E
4500-CN G
4500-F-B
4500-F-C
4500-F-D
4500-F-E
2340 C
4500-H*8
D3558-90(C
D4190-
82(88)
D1688-90(A
or B)
D1688-90(C
D4190-
82(88)
D2036-91(A)
D2036-91(B)
D1179-88(B)
D1179-88(A)
D1126-
86(92)
D1293-
84(90) (A
or B)
1-3270-85
or
I-3271-859.
1-3300-85
1-4327-85
1-1338-85
1-1586-85
Note 34.
974. 273
p. 37
Note 34.
Note 19.
p. 22. 9
973. 52B3
973. 413
Note 21.
-------
Std.
EPA1'35 Methods ASTM USGS2 Other
by:
AA direct aspiration
AA furnace
ICP/AES36
DCP36, or
Colorimetric
{Phenanthroline)
-31. Kjeldahl
. Nitrogen — Total, (as N),
mg/L:
Digestion and distillation
followed by
Titration
Nesslerization
Electrode
Automated phenate
Colorimetric
Semi-automated block
digester Colorimetric,
or
Manual or block digester
Potent iometric
^^^Laad — Total4, mg/L;
^•Rsstion4 followed
AA direct aspiration36
AA furnace
ICP/AES36
DCP36
Voltametry11, or
Colorimtric (Dithizone)
3 5 . Mercury — Total4 ,
mg/L: .
Cold vapor, manual or
Automated
37. Nickel— Total4,
mg/L; Digestion4'
followed by:
AA direct aspiration
AA furnace
ICP/AES36
DCP36, or
Colorimetric (heptoxime)
38. Nitrate (as N), mg/L:
Colorimetric (Brucine
sulfate), or Ni-
*te-nitrite N minus
rite N (See
236.1
236.2
5200.7
351.3
351.3
351.3
351.3
351.1
351.2
351.4
239.1
239.2
5200.7
245.1
245.2
249.1
249.2
5200.7
352.1
18th Ed.
3111 B or
C
3113 B
3120 B
3500-Fe D
4500-NH3B
or C
4500-NH,E
. 4500-NH,C
4500-NH3F
or G
3111 B or
C
3113 B
3120 B
3500-Pb D
3112 B
3111 B or
C
3113 B
3120 B
3500-Ni D
D1068-90(A
or B)
D1068-90(C
D4190-
82(88)
D1068-90(D
-
D3590-89(A)
D3590-89(A)
D3590-89(A;
D3590-89(B
D359-89(A)
D3559-90(A
or B)
D3559-90(D
D4190-
82(88)
D3559-90(C)
D3223-91
D1886-90(A
or B)
D1886-90(C
D4190-
82(88)
1-3381-85
I-4551-788
1-3399-85
1-3462-85
1-3499-85
974. 273
Note 34.
Note 22.
973. 483
974. 273
Note 34.
977. 223
Note 34.
973. 53
419D17
p.289
-------
EPA
1,35
parameters 39 and 40)
39. Nitrate-nitrite (as N),
mg/L:
Cadmium reduction, Manual
or
Automated, or
Automated hydrazine
40. Nitrite (as N), mg/L;
Spectrophotometric:
.Manual or
Automated (Diazotization)
41. Oil and grease—Total
recoverable, mg/L:
Gravimetric (extraction)
42. Organic carbon—Total
(TOC), mg/L:
Combustion or oxidation
43. Total Kjeldahl N
(Parameter 31) minus
ammonia N (Parameter 4)
44. Orthophosphate (as P),
mg/L Ascorbic acid
method:
Automated, or
Manual single reagent
Manual two reagent
46. Oxygen, dissolved,
mg/L:
Winkler (Azide
modification), or
Electrode
18. Phenols, mg/L:
Manual distillation26
Followed by:
Colorimetric (4AAP)
manual, or
Automated^'
50. Phosphorus—Total,
mg/L:
Persulfate digestion
followed by
Manual or
Automated ascorbic acid
reduction
Semi-automated block
digestor
353.3
353.2
353.1
354.1
413.1
17
415.1
365.1
365.2
365.3
360.2
360.1
420.1
420.1
420.2
365.2
365.2 or
365.1
365.4
Std. ,
Methods
18th Ed.
4500-NO3E
4500-NCsF
4500-NO3H
4500-NO,
5520 B
5310 B,
C, or D
ASTM
USGS"
4500-P F
4500-P E
4500-0 C
4500-0-G
4500-P
B,5
4500-P F
D3867-90(B)
D3867-90(A)
D2579-85(A
or B)
D515-88(A)
D888-92(A)
D888-92(B)
D515-88(B)
1-4545-85
1-4601-85
I-1575-788
I-1576-788
14600-85
Other
Note 25.-
973.473
p. 14
24
973.563
973.553
973.45B3
Note 27.
Note 27.
973.553
973.563
-------
1,35
55. Residue—nonfilterable
(TSS), mg/L:
Gravimetric, 103-105°
post washing of residue
56. Residue—settleable,
mg/L:
Volumetric, (Imhoff cone),
or gravimetric
50". Selenium—Total4,
mg/L; Digestion4
followed by:
AA furnace
ICP/AES,36 or
AA gaseous hydride
54. Specific conductance,
micromhos/cm at 25°C:
Wheatstone bridge
55. Sulfate (as SO4"2),
mg/L:
Automated colorimetric
(barium chloranilate)
Gravimetric
«dimetric, or
Ifide (as S), mg/L:
metric (iodine), or
Colorimetric (methylene
blue)
57. Sulfite (as SO3"2),
mg/L:
Titrimetric
(iodine-iodate)
S8. Surfactants, mg/L:
Colorimetric (methylene
blue)
59. Temperature, °C:
Thermometric
'1. Tin—Total,4 mg/L;
Digestion4 followed
by:
AA direct aspiration
AA furnace, or
ICP/AES
73. Turbidity, NTU:
Nephelometric
;5. Zinc—Total4, mg/L;
Digestion4, followed
ect aspiration36
EPA
160.2
160.5
270.2
5200.7
120.1
375.1
375.3
375.4
376.1
376.2
377.1
425.1
170.1
282.1
282.2
5200.7
180.1
289.1
Std. ,
Methods
18th Ed.
2540 D
2540 F
ASTM
Other
3113 B
3120 B
3114 B
2510 B
4500-SO,"
2C or D
4500-S'2E
4500-S'2D
4500-SO,"2
2B
5540 C
2550 B
3111 B
3113 B
2130 B
3111 B or
D3859-88(A
D1125-91(A
D516-90
D2330-88
D1889-88(A
D1691-90
1-3765-85
1-3667-85
1-1780-85
1-3840-85
I-3850-788
1-3860-85
1-3900-85
973.403
925.543
426C30
Note 32.
974.273, 379
-------
AA furnace
ICP/AES36
DCP,36 or
Colorimetric (Dithizone)
or
riginal sample solution for total metals) may be omitted for AA (direct aspiration or graphite
"urnace) and ICP analyses, provided the sample solution to be analyzed meets the following
Criteria:
:. Has a low COD (<20),
'. Is visibly transparent with a turbidity measurement of 1 NTU or less,
Is colorless with no perceptible odor, and
i. Is of one liquid phase and free of particulate or suspended matter following
-cidification.
The full text of Method 200.7, 'Inductively Coupled Plasma Atomic Emission Spectrometric
lethod for Trace Element Analysis of Water and Wastes,' is given at Appendix C of this Part
.36.
Manual distillation is not required if comparability data on representative effluent
amples are on company file to show that this preliminary distillation step is not necessary^
.owever, manual distillation will be required to resolve any controversies. ^^
-------
lonia, Automated Electrode Method, Industrial Method Number 379-75 WE, dated February 19,
I, Bran & Luebbe (Technicon) Auto Analyzer II, Bran & Luebbe Analyzing Technologies, Inc.,
ford, N.Y. 10523.
3. The approved method is that cited in 'Methods for Determination of Inorganic Substances in
Water and Fluvial Sediments', USGS TWRI, Book 5, Chapter Al (1979).
9. American National Standard on Photographic Processing Effluents, Apr. 2, 1975. Available
from ANSI, 1430 Broadway, New York, NY 10018.
11. The use of normal and differential pulse voltage ramps to increase sensitivity and
resolution is acceptable.
12. Carbonaceous biochemical oxygen demand (CBOD5) must not be confused with the traditional
3ODS"test which measures 'total BOD'. The addition of the nitrification inhibitor is not a-
"procedural option, but must be included to report the CBOD5 parameter. A discharger whose
permit requires reporting the traditional BOD5 may not use a nitrification inhibitor in the
procedure for reporting the results. Only when a discharger's permit specifically states CBOD5s
required can the permittee report data using the nitrification inhibitor.
13. QIC Chemical Oxygen Demand Method, Oceanography International Corporation, 1978, 512 West
Loop, P.O. Box 2980, College Station, TX 77840.
14. Chemical Oxygen Demand, Method 8000, Hach Handbook of Water Analysis, 1979, Hach Chemical
Company, P.O. Box 389, Loveland, CO 80537.
15. The back titration method will be used to resolve controversy.
16. Orion Research Instruction Manual, Residual Chlorine Electrode Model 97-70, 1977, Orion
Research Incorporated, 840 Memorial Drive, Cambridge, MA 02138. The calibration graph for the
»" ' residual chlorine method must be derived using a reagent blank and three standard
ions, containing 0.2, 1.0, and 5.0 ml 0.00281 N potassium iodate/100 ml solution,
ctively.
17. The approved method is that cited in Standard Methods for the Examination of Water and
•Jastewater, 14th Edition, 1976.
19. Copper, Biocinchoinate Method, Method 8506, Hach Handbook of Water Analysis, 1979, Hach
-hemical Company, P.O. Box 389, Loveland, CO 80537.
20. After the manual distillation is completed, the autoanalyzer manifolds in EPA Methods
335.3 (cyanide) or 420.2 (phenols) are simplified by connecting the re-sample line directly to
:he sampler. When using the manifold setup shown in Method 335.3, the buffer 6.2 should be
replaced with the buffer 7.6 found in Method 335.2.
•21. Hydrogen ion (pH) Automated Electrode Method, Industrial Method Number 378-75WA, October
1976, Bran & Luebbe (Technicon) Autoanalyzer II. Bran & Luebbe Analyzing Technologies, Inc.,
Slmsford, N.Y. 10523.
22. Iron, 1,10-Phenanthroline Method, Method 8008, 1980, Hach Chemical Company, P.O. Box 389,
^oveland, CO 80537.
24. Wershaw, R.L., et al, 'Methods for Analysis of Organic Substances in Water,' Techniques of
•Jater-Resources Investigation of the U.S. Geological Survey, Book 5, Chapter A3, (1972 Revised
1987) p. 14.
25. Nitrogen, Nitrite, Method 8507, Hach Chemical Company, P.O. Box 389, Loveland, CO 80537.
26. Just prior to distillation, adjust the sulfuric-acid-preserved sample to pH 4 with 1+9
JaOH.
27. The approved method is cited in Standard Methods for the Examination of Water and
14th Edition. The colorimetric reaction is conducted at a pH of 10.0±0.2. The
methods are given on pp. 576-81 of the 14th Edition: Method 510A for distillation,
-------
Method 510B for the manual colorimetric procedure, or Method 510C for the manual
spectrophotometric procedure.
30. The approved method is that cited in Standard Methods for the Examination of Water and
tfastewater, 15th Edition.
31. EPA Methods 335.2 and 335.3 require the NaOH absorber solution final concentration to be
adjusted to 0.25 N before colorimetric determination of total cyanide.
32. Stevens, H. H., Ficke, J. F., and Smoot, G. F., "Water Temperature—Influential Factors,
Field Measurement and Data Presentation', Techniques of Water-Resources Investigations of the
j.S. Geological Survey, Book 1, Chapter Dl, 1975.
33. Zinc, Zincon Methpd, Method 8009, Hach Handbook of Water Analysis, 1979, pages 2-231 arid
2^333, Hach Chemical Company, Loveland, CO 80537.
34. 'Direct Current Plasma (DCP) Optical Emission Spectrometric Method for Trade Elemental
Analysis of Water and Wastes, Method AES0029,' 1986—Revised 1991, Applied Research
Laboratories, Inc., 24911 Avenue Stanford, Valencia, CA 91355.
35. Precision and recovery statements for the atomic absorption direct aspiration and graphite
furnace methods, and for the spectrophotometric SDDC method for arsenic are provided in
Appendix D of this part titled, 'Precision and Recovery Statements for Methods for Measuring
•totals'. .
36. 'Closed Vessel Microwave Digestion of Wastewater Samples for Determination of Metals', CEM
:orporation, P.O. Box 200, Matthews, NC 28106-0200, April 16, 1992. Available from the CEM
Corporation.
(c) 1993 The Bureau of National Affairs, Inc.
------- |