EXPERIMENTAL OBJECTIVE
•Determine what environmental conditions result in the worst
•corrosion of concrete pipe.
•
•Test variables:
•
•TYPE OF BACTERIA PRESENT:
• Thiobacillus (T) + Acidiphilium (A) VS. T ONLY VS. NO BACTERIA VS. KILLED BACTERIA (no bacteria and killed bacteria are controls)
•
•pH:
• pH 8 VS. pH 4 VS. CONSTANT pH 8
•
•TEMPERATURE:
• 25C VS. 30C VS. 35C
•
•SULFUR CONCENTRATION:
• 0.5 g/L VS. 1 g/L VS. 5 g/L VS. 10 g/L
•
•
DESPITE OUR EFFORT TO KEEP THE CONDITIONS CONSTANT THERE WERE SOME VARIANCES WE COULDN’T ELIMINATE.
SUCH AS-
   -BACTERIA:
     -CONTROLS WERE CONTAMINATED WITH LIVE BACTERIA THAT I DID NOT PUT IN THE SAMPLES.
   -PH:
     -BACTERIA PRODUCED H2SO4 (LOWER PH) AND CALCIUM RELEASED (HIGHER PH).
   -TEMPERATURE:
     -REASONABLY CONSTANT
   -SULFUR:
     -LIQUID MEDIA CONTAINED SULFUR THAT WAS NOT HOMOGENEOUS.
     -SULFUR IS NOT SOLUBLE, SO IT WOULD FLOAT ON TOP AND SPLASH ON SIDES OF BEAKER.
     -THE SULFUR IS A SUBSTRATE FOR THE THIOBACILLUS, SO THE THIOBACILLUS WAS ALSO NOT
     HOMOGENEOUS OR NOT IN THE MEDIA ALL.