Method for recovering and separating metals from waste streams

A process for separating and recovering metals from contaminated groundwater comprising:

• (a) intercepting a contaminated plume downstream from a source of contaminated water;
• (b) segregating and removing insoluble and volatile organic matter from said intercepted contaminated plume to form a substantially liquid stream of said contaminated groundwater;
• (c) feeding said liquid stream of contaminated groundwater to a chamber;
• (d) adjusting the pH of said liquid stream of contaminated groundwater to from about 3.5 to about 10.5;
• (e) adding a metal complexing agent to said liquid stream of contaminated groundwater to form metal ion complexes of the metals in said contaminated groundwater, said metal complexing agent being a mixture of water, an inorganic base selected from the group consisting of sodium hydroxide, calcium hydroxide and potassium hydroxide, and a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate, and the salts thereof;
• (f) adding a flocculating agent and calcium chloride as an aggregating agent to said liquid stream of contaminated groundwater to cause said metal ion complexes to precipitate in the form of a sludge and leave clean, uncontaminated water;
• (g) dewatering and drying said sludge to a substantially anhydrous state;
• (h) melting said dewatered and dried sludge to recover said metals therefrom in solid form;
• and,
• (i) discharging said clean, uncontaminated water for further processing for use as potable water or to the foot of said contaminated plume such that said contaminated plume is prevented from further migration.

A process for separating and recovering metals from a water source intended for use as potable water comprising:

• (a) segregating and removing insoluble and volatile organic matter from said water source;
• (b) removing nitrates from said water source;
• (c) adding ionic aluminum or ionic iron to said water source to improve the color, reduce the turbidity and destroy bacteria in said water source;
• (d) adding a metal complexing agent to said water source to form metal ion complexes of the metals in said water source, said metal complexing agent being a mixture of water, an inorganic base selected from the group consisting of sodium hydroxide, calcium hydroxide and potassium hydroxide, and a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate, and the salts thereof;
• (e) adding a flocculating agent and calcium chloride as an aggregating agent to said water source to cause said metal ion complexes to precipitate in the form of a sludge and leave a cleaned water source;
• (f) dewatering and drying said sludge to a substantially anhydrous state;
• (g) melting said dewatered and dried sludge to recover said metals therefrom in solid form;
• (h) treating said cleaned water source to remove excess calcium and magnesium to a level of from about 75 to about 120 mg/l calcium carbonate;
• (i) filtering said cleaned water source to remove residual particulate matter and offensive tastes and odors therefrom;
• and,
• (j) disinfecting said cleaned water source to reduce the pathogens remaining therein to an acceptable level for potable use.

A process for separating and recovering metals from contaminated standing water comprising:

• (a) pumping said contaminated standing water into a chamber;
• (b) adjusting the pH of said contaminated standing water to from about 3.5 to about 10.5;
• (c) adding a metal complexing agent to said contaminated standing water to form metal ion complexes in said contaminated standing water, said metal complexing agent being a mixture of water, an inorganic base selected from the group consisting of sodium hydroxide, calcium hydroxide and potassium hydroxide, and a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate, and the salts thereof;
• (d) adding a flocculating agent and calcium chloride as an aggregating agent to said contaminated standing water to cause said metal ion complexes to precipitate in the form of a sludge;
• (e) removing said sludge from said chamber so that cleaned water remains therein;
• (f) dewatering and drying said sludge to a substantially anhydrous state;
• (g) melting said dewatered and dried sludge to recover said metals therefrom in solid form;
• and,
• (h) discharging said cleaned water from said chamber.

A process for separating and recovering metals from waste streams containing more than about 2% by weight solids in solution comprising:

• (a) diverting and isolating a portion of said solids containing waste stream;
• (b) removing insoluble and volatile organic matter from said solids containing waste stream to produce a substantially solid waste residue;
• (c) washing said solid waste residue until a homogeneous waste stream solution is obtained;
• (d) feeding said homogeneous waste stream solution into a chamber;
• (e) adjusting the pH of said waste stream solution to from about 3.5 to about 10.5;
• (f) adding a metal complexing agent to said waste stream solution to form metal ion complexes in said waste stream solution, said metal complexing agent being a mixture of water, an inorganic base selected from the group consisting of sodium hydroxide, calcium hydroxide and potassium hydroxide, and a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate, and the salts thereof;
• (g) adding a flocculating agent and calcium chloride as an aggregating agent to said waste stream solution to cause said metal ion complexes to precipitate in the form of a sludge and leave remaining an effluent;
• (h) dewatering and drying said sludge to a substantially anhydrous state;
• (i) melting said dewatered and dried sludge to recover said metals therefrom in solid form;
• and,
• (j) discharging said effluent into the ground, a sewerage system, or a potable water distribution system.

A process for separating and recovering electroless nickel and electroless copper from electroplating waste streams comprising:

• (a) feeding an electroplating waste stream containing electroless nickel and electroless copper into a chamber;
• (b) adjusting the pH of said waste stream to from about 6.0 to about 8.5;
• (c) adding sodium sulfate and ferrous sulfate as reducing agents to said waste stream;
• (d) adding a flocculating agent and calcium chloride as an aggregating agent or a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate and the salts thereof as a precipitating agent to said waste stream to cause said electroless nickel and electroless copper to precipitate in the form of a sludge;
• (e) dewatering and drying said sludge to a substantially anhydrous state;
• and,
• (f) melting said dewatered and dried sludge to recover said electroless nickel and electroless copper therefrom in solid form.

A process for separating and removing radioactive metals from waste streams comprising:

• (a) feeding a waste stream containing radioactive metals into a chamber;
• (b) adjusting the pH of said waste stream to from about 3.5 to about 10.5;
• (c) adding a metal complexing agent to said waste stream to form metal ion complexes of said radioactive metals, said metal complexing agent being a mixture of water, an inorganic base selected from the group consisting of sodium hydroxide, calcium hydroxide and potassium hydroxide, and a thiocarbamate or dithiocarbamate selected from the group consisting of dimethyldithiocarbamate, diethyldithiocarbamate, and the salts thereof;
• (d) adding a flocculating agent and calcium chloride as an aggregating agent to said waste stream to cause said metal ion complexes to precipitate in the form of a sludge;
• and,
• (e) dewatering said sludge to a substantially anhydrous state.