MATERIALS & METHODS
Materials
 List/bullet each and every material, piece of equipment, etc. used while performing the
experiment.
Methods
This section describes how lab/field work was carried out.
 Describe in detail the methods used to collect data.
 Number each step.
 Other scientists in the field should be able to reproduce the experiment using information
in this section.
 Avoid the use of first person pronouns (I, me, and mine)…
 Indicate your control, independent variable and dependent variable after your procedures
(List them under your procedures.)
CHECK: Are there enough details provided for you to effectively reproduce the study? If
not, what could be added to make it more useful?
Materials and Methods
Materials:

(2) clear vinyl tubes (2.5 cm in diameter,

(4) large heavy duty garbage bags
15 cm long)

(1) large 2m role of window sealant tape
(4) large clear plastic containers (80 cm

(1) pair of scissors
by 45cm by 35ccm)

(1) metric ruler

(1) 5kg bag of potting soul

(1) glass beaker

(1) bacteria culture of P. Aeruginosa

(2) clear 8oz plastic cups

500 mL of paint thinner

(2) PVC piping ring, 10cm in diameter

(1) gas detector pump

(1) box of latex gloves

(1) hand held drill

(1) stopwatch

(10) benzene detector tubes

(1) roll of scotch tape

(10) toluene detector tubes

500 mL of water

Methods:
Part A: Creating the Biofilter Chamber Base
1. Drill a hole 2.5mm in diameter on the 40cm by 35cm panel of the plastic container, approximately 5
cm from the top edge of the panel and about 10 cm from the right edge of the panel.
2. Cut a 2.5cm by 3cm piece of scotch tape.
3. Fold the 2.5 cm of tape inward so the adhesive side is facing downward, forming a flap.
4. Label one of these containers Group A-control, Measurement Chamber and the other Group AControl, Biofiltration Chamber.
5. Repeat steps 2-3 for the other 2 containers.
6. Place the adhesive side of the tape over the hole just drilled.
7. Drill a hole that is 2.5cm in diameter on the 80cm by 40cm panel of the container. This hole should
be about 20 cm from the top of the container and inward from the right by about 20 cm.
8. Repeat steps 5-7 for all the other 3 containers.
9. Label the two unlabeled containers Group A-control Biofilter Chamber and Group B-Biofiltration,
Biofilter Chamber.
10. Place the two containers in Group A with the holes 2.5 cm in diameter facing directly against each
other.
11. Insert one end of the tube into a container.
12. Seal and attach the tube with 20 cm of window tape.
13. Attach the PVC piping ring to any inner corner of the container using window sealant tape.
14. Place the plastic cup into this ring.
15. Repeat steps 11-12 for Group B.
Part B: Experimental Setup
16. Put on a fresh pair of latex gloves.
17. Using a pair of scissors cut a 10cm slit in the 5kg bag of potting soil.
18. Add the potting soil into the container labeled Group B- Biofiltration, Biofiltration Chamber.
19. Add 500 mL of water to the soil.
20. Carefully open and add the bacteria culture following Ward’s Bacteria Guidelines (see logbook).
21. Make sure all holes, areas, and tubes are sealed and secure.
22. Add 250 mL of paint thinner to each cup placed earlier.
23. Within a one minute time frame, stretch the heavy duty garbage bag over the top of each container.
24. Seal the bag around the top of the container using window sealant tape.
25. Leave the containers for 24 hours.
Part C: Taking Measurements
26. Using the instructions from the Rae Systems handbook (see logbook), take benzene and toluene
measurements in ppm. This will involve the use of the benzene detector tubes, toluene detector
tubes, a stopwatch, and a gas detection pump. Take 1 measurement of benzene and toluene from
each container and record data in logbook
Note: When measuring open the flap for 2.5mm in diameter hole to allow tubes to pass through for
accurate readings.
Control: Group A- Container with no Biofiltration
Independent Variable: Biofiltration
Dependent Variable: Amount of Benzene in ppm, Amount of Toluene in ppm