In situ immobilization of metals in waste stacks and waste stack affected zones

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• treating a surface pool which exists on at least portions of the waste stack using a pool treatment composition;
• providing at least one microbe in the waste stack affected zone;
• said at least one microbe being capable of growing in the presence of said treatment composition;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• said pool treatment composition including at least one microbe nutrient which is a nutrient capable of sustaining activity of the at least one microbe;
• percolating pool treatment composition into the waste stack from the surface pool;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• flowing a liquid onto the waste stack;
• said liquid including at least one microbe nutrient which is capable of sustaining activity of at least one microbe;
• providing at least one microbe in the waste stack affected zone to receive said at least one microbe nutrient from said liquid flowed onto the waste stack;
• said at least one microbe being capable of growing in the presence of said liquid and said at least one microbe nutrient;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• flowing a waste liquid onto the waste stack;
• said waste liquid including at least one microbe nutrient which is capable of sustaining activity of at least one microbe;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• flowing a waste liquid onto the waste stack;
• said waste liquid including at least one microbe and at least one microbe nutrient which is capable of sustaining activity of the at least one microbe;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• flowing a waste liquid onto the waste stack;
• said waste liquid being at a low pH;
• said waste liquid including materials which comprise the waste stack and at least one microbe nutrient which is capable of sustaining activity of at least one microbe;
• said waste liquid further including at least one microbe;
• said at least one microbe being inactive in said waste stack affected zone until and at locations in which the pH increases;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.

A process for in situ immobilization of metals in a waste stack affected zone, the waste stack affected zone including a waste stack and any adjacent boundary zone, the process comprising:

• adding at least one microbe nutrient which is capable of sustaining activity of at least one microbe to a waste liquid;
• flowing the waste liquid with added at least one microbe nutrient onto the waste stack;
• said waste liquid being at a low pH;
• said waste liquid being a slurry which includes materials which comprise the waste stack;
• wherein there is at least one microbe within the waste stack affected zone;
• said at least one microbe being inactive in said waste stack affected zone except at locations in which the pH increases due to neutralization of the low pH waste liquid as the liquid flows into the waste stack;
• said at least one microbe also being capable of producing microbial sulfides which are sulfide by-products of microbial activity in the waste stack affected zone;
• reacting the microbial sulfides in situ with metal ions or metal-containing compounds contained in said waste stack affected zone to form metal sulfides;
• reducing solubility of the metal ions or metal-containing compounds contained in the waste stack affected zone as a result of forming the metal sulfides;
• inhibiting the migration rate of metal ions or metal-containing compounds within or from the waste stack affected zone.