Methods and systems for bioremediation of heavy metal contaminants in waste materials (e.g., sludge and combustion wastes from a coal-fixed power plant). The systems described in the present application include at least one waste treatment unit (e.g., a flue gas cleaner or a waste lagoon) that includes one or more selected bacterial strains disposed therein consume and/or reclaim at least a portion of the heavy metal in the combustion wastes. Methods include inoculating a waste treatment unit with one or more selected bacteria that consume and/or reclaim at least a portion of the heavy metal in the combustion wastes. Methods may include periodic reinoculation of the waste treatment unit with fresh bacteria and period recovery of the bacteria from the waste treatment unit.

Embodiments provide methods and strictures for purification or volume reduction of a brine by an advanced vacuum distillation process (AVMD) to achieve higher flux by passage of vapors through an AVMD distillation unit. In one example, brine is circulated in a tank. The tank may include one or more membrane pouches that are submerged in the circulating brine or placed above the water level of the hot circulating brine. In other embodiments the membrane pouches are outside of the tank that includes the hot circulating brine but still in communication with it. The circulating brine is heated, allowing creation of water vapor. Using a vacuum, the water vapor is drawn through the membrane, where it may be condensed and subjected to further beneficial use. This process can concentrate to levels to generate crystals or solids, which can be separated and utilized.

A process for treating a flue gas desulfurization discharge stream containing dissolved sulfates is presented. Soluble barium compounds, such as barium chloride or barium carbonate are added to the stream in lieu of the traditional two-step lime/carbon dioxide process. The barium compounds cause the sulfate to precipitate as insoluble barium sulfate. The barium sulfate solids settle out of the discharge stream and can be filtered from the process water. The use of soluble barium compounds eliminates the need for subsequent pH adjustment, results in lowering calcium and magnesium concentrations in the discharge stream, and decreases scaling potential in downstream equipment.

Systems and methods of performing temperature swing solvent extraction (TSSE) descaling of produced water and desalination of high-salinity brines, e.g., those having a total dissolved solids (TDS) greater than about 250,000 ppm are capable of producing descaled water products including less than about 5% weight percent TDS. The brine/produced water feedstreams and combined with a solvent having temperature-dependent water solubility at a temperature T.sub.L. Water is extracted from the feedstream into the solvent to form a water-in-solvent extract component and a raffinate component, from which a solid phase can be precipitated as more water is portioned in the solvent and basicity increases. Heating of the water-in-solvent extract component reduces the solubility of the water therein, producing a biphasic mixture of dewatered solvent and descaled water that can be separated. Because these systems and methods do not require a phase change of water, these products are achieved with significantly higher energy efficiencies when compared to evaporation-based thermal methods.

The present invention is directed to a ligated metal-organic framework (MOF) for use in removing both anionic and cationic species from a liquid or liquid stream. The present invention also provides methods for placing the MOF on a substrate to form a MOF-containing product that can be used in the removal of certain species from a given fluid. The MOF may be a Zr-based MOF, such as NU-1000, for removal of certain anions, such as oxy-anions, or having an attached thiosulfonyl-thiol (—SO.sub.2—S—R.sub.2—SH, where R.sub.2 is an alkyl group) ligand for complexation with certain cationic species in addition to the anions. The substrate may be any substrate to which a given MOF may be attached, including inert polypropylene polymer resin beads, a macroscopic fabric such as a mesh material or mesh filter, and a molecular fabric.

The present application provides a waste water preconditioning system for limiting mercury concentrations in a waste water stream resulting from treatment of a flue gas. The waste water preconditioning system may include a wet flue gas desulfurization system for treating the flue gas with an aqueous alkaline slurry, a sulfite detector to determine the concentration of sulfite in the aqueous alkaline slurry, and to produce the waste water stream with a mercury concentration of less than about five micrograms per liter. The waste water preconditioning system also may include a waste water treatment system downstream of the wet flue gas desulfurization system.

An efficient, cost-effective, and efficacious technique for removing coal ash and other pollutants from waterways, ponds, marshes, holding tanks and other water sources and supplies. An apparatus comprising an open cage including electromagnets and/or permanent magnets and/or electrodes is supplied with electrical power to extract materials such as rare earth elements and/or heavy metals. The materials levitate to the surface, forming a shiny while leaving water substantially free of such materials.

A method of treating an aqueous solution comprises forming a treatment stream comprising a condensable material. The treatment stream is introduced to an aqueous solution comprising water and a solute to fractionally precipitate the solute out of the aqueous solution and form a solids stream comprising the solute and an aqueous liquid stream comprising at least one solute-depleted solution of the water and the condensable material. The condensable material of at least a portion of the aqueous liquid stream is separated from the water of the at least a portion of the aqueous liquid stream to at least partially reform the treatment stream and form an aqueous liquid product stream depleted in the solute. Aqueous solution treatment systems and additional methods of treating an aqueous solution are also described.

A method and apparatus are disclosed for treating process water which is loaded with gaseous compounds and/or possibly with solids and comes from a wet-cleaning installation for cleaning process gas, e.g., from a melt-reduction subassembly or from a direct-reduction subassembly. Process water is introduced in a tank in a first process stage and degassed on the basis of reduced solubility of the dissolved compounds. The tank has, on its upper side, a gas-collecting chamber, in which the separated-off gases are collected and from which these are discharged. Likewise, the treated process water is discharged from the tank via a drainage means.

The invention relates to a method for the precipitation of arsenic and heavy metals from acidic, in particular sulphuric acid, process water (12), containing both arsenic and heavy metals, comprising a precipitation method phase (II) with a sulphide precipitation stage (C) in which arsenic and at least one primary heavy metal are precipitated together, wherein a sulphide precipitating agent (16) is added to the process water (12) such that arsenic is precipitated as arsenic sulphide and the at least one primary heavy metal is precipitated as metal sulphide. The sulphide precipitation stage (C) comprises a first sulphide precipitation step (C.1) in which a sulphide precipitating agent is added to the process water (12) in a first sulphide precipitation reactor (14), whereby an intermediate fluid (22) is generated still containing arsenic or still containing arsenic and the primary heavy metal. The intermediate fluid (22) is transferred into a second sulphide precipitation reactor (30) after the first sulphide precipitation step (C.1). The sulphide precipitation stage (C) comprises a second sulphide precipitation step (C.2) in which a sulphide precipitating agent is added to the intermediate fluid (22) in the second precipitation reactor, whereby a residual fluid (32) is generated which is substantially free from arsenic.