Compositions for controlling microbially induced concrete corrosion
This invention provides in one aspect compositions that improve the corrosion-resistance of cementitious materials. In certain embodiments, the compositions of the invention inhibit the growth of acidophilic bacteria thriving in/on cementitious material.
1 . A composition comprising:
a cementitious substrate and at least one fine aggregate associated with at least one heavy metal selected from the group consisting of cadmium (Cd), zinc (Zn), copper (Cu), silver (Ag), cobalt (Co), lead (Pb), molybdenum (Mo), and tungsten (W),
wherein the fine aggregate is present throughout the composition and comprises at least one of granular activated carbon (GAC), steel slag, or a combination thereof,
wherein the steel slag comprises about 20% to about 45% (w/w) of the fine aggregate; and
wherein the fine aggregate further comprises sand in an amount of about 40 to about 60% (w/w) of the fine aggregate.
2 . The composition of claim 1 , wherein at least one of the following applies:
i the GAC comprises at least one of unmodified GAC and surface area-modified granular activated carbon (GAC-Acid);
ii) the GAC comprises at least one heavy metal selected from the group consisting of cadmium (Cd), zinc (Zn), copper (Cu), silver (Ag), cobalt (Co), lead (Pb), molybdenum (Mo), and tungsten (W);
iii) the GAC comprises about 1 to about 10% (w/w) of the fine aggregate;
iv) the GAC comprises either:
(a) Cu having a concentration of about 10 to about 20 mg Cu/g GAC; or
(b) Cu having a concentration of about 5 to about 15 mg Cu/g GAC and Co having a concentration of about 0.01 to about 10 mg Co/g GAC.
3 . The composition of claim 1 , wherein the steel slag comprises at least one heavy metal selected from the group consisting of cadmium (Cd), zinc (Zn), copper (Cu), silver (Ag), cobalt (Co), lead (Pb), molybdenum (Mo), and tungsten (W).
4 . The composition of claim 3 , wherein the steel slag comprises either:
(a) Cu having a concentration of about 17 to about 19 mg Cu/g steel slag; or
(b) Cu having a concentration of about 16 to about 18 mg Cu/g steel slag and Co having a concentration of about 5 to about 10 mg Co/g steel slag.
5 . The composition of claim 1 , wherein the steel slag comprise about 40% (w/w) of the fine aggregate.
6 . The composition of claim 1 , wherein:
(a) the GAC comprises GAC-Acid, wherein:
the GAC-Acid is associated with Cu and Co,
wherein the concentration of Cu is about 8.3 mg Cu/g GAC and
the concentration of Co is about 0.03 mg Co/g GAC; and
the GAC-Acid comprises about 1 % (w/w) of the fine aggregate;
(b) the steel slag comprises BOF-S, wherein:
the BOF-S is associated with Cu,
wherein the concentration of Cu is about 17.9 mg Cu/g steel slag; and
the BOF-S comprises about 40% (w/w) of the fine aggregate; and
(c) the fine aggregate further comprises sand, wherein:
the sand is Ottawa sand; and
the sand comprises about 59% (w/w) of the fine aggregate.
7 . The composition of claim 1 , wherein the at least one heavy metal comprises two heavy metals having a ratio ranging from about 1:1 to about 3:1 (w/w).
8 . The composition of claim 1 , wherein the composition makes bioavailable at least a portion of the at least one heavy metal upon contact with an environment having a pH of about 5 or less.
9 . The composition of claim 8 , wherein the bioavailability of the at least one heavy metal reduces or inhibits the growth of an acidophilic bacterium within the composition, wherein the acidophilic bacterium comprises Acidithiobacillus thiooxidans or Acidithiobacillus ferrooxidans.
10 . The composition of claim 1 , wherein the cementitious substrate comprises a non-hydraulic cement or a hydraulic cement.