AN EXPERIMENT WITH ACID MINE WATER AND
LIVING HISTORY – A COAL MINE INTERVIEW
“A TALK WITH HISTORY

LESSON PLAN CREATED BY:

JOHN S. CATTANEO

  FOR THE MON VALLEY EDUCATIONAL CONSORTIUM’S
EDUCATOR TN THE WORK PLACE

  JULY 2000

AN EXPERIMENT WITH ACID MINE WATER

CONCEPT - WATER POLLUTION IS A SERIOUS ECOLOGICAL PROBLEM. IN SOUTHWESTERN PENNSYLVANIA ACID MINE WATER IS A MAJOR SOURCE OF POLLUTION. WATER IS A RENEWABLE RESOURCE BUT CONTAMINATES SUCH AS ACID MINE WATER MAKES PURIFICATION A LONG TERM PROJECT AND EXTREMELY DIFFICULT AND EXPENSIVE.

OBJECTIVES:

• STUDENTS WILL CREATE A SAMPLE OF ACID MINE WATER.

• STUDENTS WILL TEST pH AND IRON LEVELS.

• STUDENTS WILL OBSERVE AND RECORD DATA.

• STUDENTS WILL HYPOTHESIZE THE EFFECTS OF CONTAMINATED WATER ON LIVING THINGS.

• STUDENTS WILL PURIFY ACID MINE WATER

MATERIALS NEEDED:

• THREE- 1 GALLON CLEAR JARS

• 10 LBS. OF CRUSHED COAL

• 10 LBS OF CRUSHED LIMESTONE

• pH INDICATOR STRIPS

• IRON INDICATOR STRIPS

• VARIOUS BEDDING PLANTS:        

  • FLOWER

  • VEGETABLE

  • CATTAIL

• TWO STICKS LONG ENOUGH TO STIR WATER
  (MARX EACH STICK FOR EACH JAR)

• STRAINER- COFFEE FILTERS

• A DRAWSTRING BAG

• TEACHER NOTES

NOTE - ACID MINE DRAINAGE (AMD) IS THE RESULT OF PYRITE (FeS2) OXIDATION. PYRITE IS AN IRON DISULFIDE THAT IS COMMONLY FOUND IN STRATA SURROUNDING COAL WHEN THE LAND IS DISTURBED AND THE PYRITE IS EXPOSED TO OXYGEN AND WATER, IT WEATHERS. THIS PRODUCTION OF IRON, SULFATE, AND ACIDITY CON­TRIBUTES TO THE DEGRADATION OF STREAMS. THE WGH METAL CONTENT AND LOW pH MAKE TIES WATER UNSAFE FOR DRINKING AND DANGEROUS TO AQUATIC PLANTS AND ANIMALS AND IS FOUND COMMONLY AS ORANGE WATER WITH ORANGE PRECIPITATE NEARBY.

NOTE - pH ISA MEASURE OF HOW ACIDIC/BASIC WATER IS. THE RANGE GOES FROM 0-14, WITH 7 BEING NEUTRAL. pHS OF LESS THAN 7 INDICATE ACIDITY, WHEREAS A pH OF GREATER THAN 7 INDICATES A BASE. pH IS REALLY A MEASURE OF THE RELATIVE AMOUNT OF FREE HYDROGEN AND HYDROXL IONS IN THE WATER. WATER THAT HAS MORE FREE HYDROGEN IONS IS ACIDIC, WHERE AS WATER THAT HAS MORE FREE HYDROXL IONS IS BASIC. SINCE pH CAN BE AFFECTED BY CHEMICALS IN THE WATER, pH IS AN IMPORTANT INDICATOR OF WATER THAT IS CHANGING CHEMICALLY. pH IS REPORTED IN ‘LOGARITHMIC UNITS LIKE THE RICHTER SCALE, WHICH MEASURES EARTHQUAKES.  EACH NUMBER REPRESENTS A 10-FOLD CHANGE IN THE ACIDITY BASICNESS OF THE WATER. WATER WITH A pH OF 515 TEN TIMES MORE ACIDIC THAN WATER HAVING A pH OF 6. POLLUTION CAN CHANGE A WATER’S pH, WHICH IN TURN CAN HARM ANIMALS AND PLANTS LIVING IN THE WATER. FOR INSTANCE, WATER COMING OUT OF AN ABANDONED COAL MINE CAN HAVE A pH OF 2, WHICH IS VERY ACIDIC AND WOULD DEFINITELY AFFECT ANY FISH CRAZY ENOUGH TO TRY TO LIVE N IT! BY USING THE LOGARITHM SCALE, MINE-DRAINAGE WATER WOULD BE 100,00 TIMES MORE ACIDIC THAN NEUTRAL WATER-- SO STAY OUT OF ABANDONED MINES!

STEP I - CREATING THE ACID MINE WATER AND CONTROL SAMPLE

• PLACE COAL N CONTAINER AND COVER WITH WATER.

• FILL CONTROL CONTAINER WITH WATER.

• TEST AND RECORD THE FOLLOWING INFORMATION - pH LEVELS OF BOTH CONTAINERS, IRON LEVELS OF BOTH CONTAINERS, COLOR OF WATER IN BOTH CONTAINERS, ODOR OF WATER IN BOTH CONTAINERS

• DO NOT DRINK THE WATER!

JAR 1  pH            IRON            COLOR ODOR
JAR 2  pH            IRON            COLOR ODOR

• DO TIES EACH DAY UNTIL pH DROPS TO 4 OR BELOW. YOU ARE THEN READY TO MOVE ON TO STEP II.

STEP II - EFFECTS OF ACID MINE WATER ON THE ENVIRONMENT.

• DIVIDE THE  PLANTS INTO TWO GROUPS AND LABEL THEM JAR I AND JAR 2

• WATER THE PLANTS AND MAKE AND RECORD OBSERVATIONS EACH DAY.

• DISCUSSION  WHAT DO YOU THINK WILL BE THE EFFECT ON EACH OF THE PLANTS? WHICH WILL DIE FIRST? HOW LONG WILL THIS TAKE? WHICH PLANTS WILL NOT DIE?

• AS YOU DISCUSS THE QUESTIONS RECORD THAT STUDENTS ANSWERS. COMPARE THEIR ANSWERS TO WHAT ACTUALLY TAKES PLACE OVER THE NEXT FEW DAYS.

• CONCLUSIONS - HAVE STUDENTS WRITE THEIR THE OBSERVATIONS AND THEIR CONCLUSIONS OF THE EFFECT OF ACID MINE WATER ON PLANTS AND ANIMALS THAT DEPEND ON THIS SOURCE OF WATER THAT HAS BECOME POLLUTED WITH ACID MINE WATER. REMEMBER DON’T DRINK THE WATER.

STEP 3- PURIFICATION OF ACID MINE WATER

• PLACE LIMESTONE INTO THE STRING BAG

• PLACE STRING BAG INTO THE THIRD CONTAINER

• USING THE FILTER, STRAIN ACID MINE WATER INTO THIRD CONTAINER.

• START TO MEASURE pH AND IRON LEVELS EACH DAY AND RECORD

• HAVE STUDENTS RECORD THEIR OBSERVATIONS ON pH, IRON, WATER COLOR AND SMELL

• AS pH LEVELS RISE AND IRON LEVELS DROP WATER IS BEING PURIFIED.

• pH LEVEL 6 TO 9IS ACCEPTABLE

• IRON LEVEL I MG!L IS ACCEPTABLE

• REMOVE STRING BAG AND OBSERVE ANY CHANGES.

• REMEMBER DO NOT DRINK THE WATER!

THE EXPERIMENT IS CONCLUDED