Abstract: A method and apparatus for extraction of precious metals from their ores and the product thereof. Oxidized ore comprising a precious metal is exposed to a leaching solution (lixiviant) comprising a relatively high concentration (fugacity) of dissolved hydrogen sulfide gas, a relatively high concentration (activity) of bisulfide ions, and a relatively low concentration (fugacity) of dissolved hydrogen gas. The hydrogen sulfide gas and bisulfide ions are preferably added to the solution by sulfate-reducing bacteria growing in a medium comprising dissolved sulfate ions and dissolved nitrate ions, but abiotic sources may also be used. Examples of such bacteria include mesophilic, fresh-water species such as Desulfobacterium catecholicum DSM 3882 and Desulfovibrio simplex DSM 4141; mesophilic, salt-water species such as Desulfovibrio salexigens DSM 2638; and thermophilic, fresh-water species such as Desulfomaculum kuznetsovii VKM B-1805. The complexed precious metal is recovered from the lixiviant.

Abstract: A distributed, unattended wastewater monitoring system that uses advances in low-energy signal processing and distributed microelectromechanical systems and that involves wireless interrogation of distributed, low-power, normally-off sensors. In a preferred embodiment, a plurality of flowmeter stations and at least one rain gauge station are networked through a base station for storm water discharge of infiltration-inflow monitoring. Wireless transceivers are used to transmit radio signals into and out of a sewer manhole.

Abstract: Underground pipelines that carry wastewater, water, natural gas, and industrial fluids deteriorate with age. This invention is a process and apparatus for installing a thermoplastic liner in a dry pipeline to accomplish in situ rehabilitation. It involves extruding a tube of thermoplastic liner material within the interior of a dried and preheated pipeline in situ, said tube having an outside diameter smaller than the inside diameter of said pipeline. The tube is next expanded so that the outside diameter of said tube is substantially equal to the inside diameter of said pipeline. The expanded tube is then cooled and hardened in a liner configuration.

Abstract: A method and apparatus for electronic media program recognition and choice are disclosed. The invention allows parental control of the individual television programs (e.g., series, episodes, or individual music videos) and radio programs that can be viewed or listened to by young children. The invention can be practiced without the need for or reliance on a Government or industry-wide program rating system or a "V-chip" approach. The invention automatically locks out (blocks) all programs that have not been determined by the parent to be suitable for child viewing. Suitable programs are unlocked and viewable whenever they are broadcast. Means are provided for implementing two strategies for discrimination among TV programs. Signal processing means and signal recognition software are relied upon in situations wherein program identification information is not encoded in the composite television signal. Two approaches to signal recognition are provided: video signal (e.g.

Abstract: A biohydrometallurgical apparatus and method for extracting precious metals, including gold and silver, from oxidized ore by means of leaching with a neutral bisulfide solution instead of cyanide, thiourea, thiosulfate, or other conventional lixiviants is disclosed. In a preferred embodiment, a first process step of conventional bio-oxidation of ore particles is accomplished to free precious metals dispersed or occluded within the ore. A portion of the acidic, base-metal sulfate leach solution produced by bio-oxidation is introduced to an anaerobic reactor. In a heap leach embodiment of the process, the anaerobic reactor is a side-stream reactor. In an alternative slurry (e.g.,vat) leaching embodiment, the anaerobic process may occur on-line. A preferably non-toxic electron donor, such as acetate or methanol (which does not bind effectively to activated carbon), is added to the anaerobic reactor to enrich within it a mixed culture of sulfate-reducing bacteria.

Abstract: A portable flow measurement system comprising a primary flow metering element and a secondary flow metering element is disclosed that will find application in metering irrigation water use, urban and rural storm water runoff, infiltration/inflow and wastewater flow rates. The primary element comprises a constriction in a closed conduit that produces pressures in the liquid flowing through it that are related to the rate of flow of the liquid. The constriction is preferably configured to cause essentially simultaneous filling of the constriction and the conduit upstream from it upon increasing flow rate and/or filling of the constriction and/or the upstream pipe before the modular limit is reached. The secondary element comprises a system for transmitting and sensing the pressures produced by the primary element, computing flow rates using the sensed pressure as a basis and storing the pressure data and/or the flow rate data.

Abstract: This invention provides a method and apparatus for transmitting and sensing liquid pressure (head) and liquid level (depth) in flow metering, tide gauge and liquid salinity or slurry density measurement applications. The invention essentially eliminates the effect of pressure sensor temperature variations and the effect of long-term pressure sensor signal drift on pressure sensing accuracy by resetting the zero and gain of the pressure sensor prior to pressure measurement. A variety of sources of a known differential pressure may be used to reset the gain of the differential pressure sensor by simultaneously exposing both sides of the differential pressure sensor to the known differential pressure. In one embodiment of the invention, the head loss through exhaust port of a spring-biased comparitor is the known pressure differential used to reset the pressure sensor gain.

Abstract: A method for bioremediation of hazardous wastes is disclosed. The method can be used for anaerobic treatment of a liquid or slurry hazardous waste stream (e.g., industrial wastewater or sludge) or for treatment of contaminated groundwater. Removal of halogenated (e.g., chlorinated) hydrocarbons, such as tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane and similar xenobiotics is possible. The method involves biotransformation of (dehalogenation) halogenated hydrocarbons by means of natural methanogenic bacteria, Methanosarcina barkeri strain 227 and/or Methanosarcina vacuolata. These methanogens can accomplish cometabolism of chlorinated hydrocarbons during metabolism of a primary substrate such as hydrogen-carbon dioxide, methanol, methylamine, dimethylamine, trimethylamine and acetate. Reductive dechlorination, energy conservation and control of air pollution are accomplished.