Abstract: A system for calibrating signals received over a power line within a vehicle includes a signal conditioning circuit that converts the analog input signals into digital input signals. In one embodiment the circuit includes an adjustable gain circuit that outputs an amplifier gain signal establishing an amplifier gain level and an amplifier that outputs amplified signals responsive to the analog input signals and the amplifier gain signal. In another embodiment, the circuit includes a bias circuit that outputs a bias signal establishing a bias level and a comparator that generates the digital input signals responsive to the analog input signals and the bias signal. A controller receives the digital input signals and generates, depending on the embodiment, one or more control signals configured to control the configuration of the amplifier gain signal and amplifier gain level and/or the bias signal and the bias level.

Abstract: A system for calibrating signals received over a power line within a vehicle includes a signal conditioning circuit that converts the analog input signals into digital input signals. In one embodiment the circuit includes an adjustable gain circuit that outputs an amplifier gain signal establishing an amplifier gain level and an amplifier that outputs amplified signals responsive to the analog input signals and the amplifier gain signal. In another embodiment, the circuit includes a bias circuit that outputs a bias signal establishing a bias level and a comparator that generates the digital input signals responsive to the analog input signals and the bias signal. A controller receives the digital input signals and generates, depending on the embodiment, one or more control signals configured to control the configuration of the amplifier gain signal and amplifier gain level and/or the bias signal and the bias level.

Abstract: Methods for improving ion flux and energy efficiency in a membrane stack of an electrodialysis unit wherein the membrane stack is disposed between an anode and a cathode each in an electrolyte of a selected concentration. Methods include increasing the concentration of the electrolyte, adding a strong base to the electrolyte and adding buffering anions to the electrolyte. Methods for cleaning the electrodes of such a unit involving involve applying a pulsed polarity reversal to the electrodes. Also provided are methods for improving unit operation by increasing the basicity of the electrolyte to the anode and increasing the acidity of the electrolyte to the cathode or alternatively or in addition, by applying heat to increase the operating temperature of at least one of the electrolyte and the treated water stream.

Abstract: Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof.

Abstract: Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof.

Abstract: Methods for improving ion flux and energy efficiency in a membrane stack of an electrodialysis unit wherein the membrane stack is disposed between an anode and a cathode each in an electrolyte of a selected concentration. Methods include increasing the concentration of the electrolyte, adding a strong base to the electrolyte and adding buffering anions to the electrolyte. Methods for cleaning the electrodes of such a unit involving involve applying a pulsed polarity reversal to the electrodes. Also provided are methods for improving unit operation by increasing the basicity of the electrolyte to the anode and increasing the acidity of the electrolyte to the cathode or alternatively or in addition, by applying heat to increase the operating temperature of at least one of the electrolyte and the treated water stream.

Abstract: A method and device for measuring release rates of contaminants in at least one of a fast release mode and a slow release mode in which a volatile liquid sample is introduced into a sealed transparent reactor vessel having at least one sorbent contained within the transparent reactor vessel and a separator for preventing direct contact between the at least one adsorbent and the at least one volatile liquid sample in the transparent reactor vessel, whereby substantially zero headspace is maintained within the transparent reactor vessel. At least one solvent soluble constituent present in the at least one volatile liquid sample is passed through the separator, resulting in sorption of the at least one solvent soluble constituent by the at least one sorbent. In accordance with one preferred embodiment, the separator is a dialysis bag contained in the transparent reactor vessel into which the resin is placed.

Abstract: A method for removing volatile and semi-volatile contaminants from groundwater in which the contaminants are stripped from the groundwater by sparging with an inert carrier gas and the stripped contaminants are transported into a bioactive zone into which at least one gaseous oxidant and at least one nutrient are independently injected, thereby stimulating at least one microbial culture associated with the bioactive zone to remove the stripped contaminants from the bioactive zone. By decoupling the sparging of the groundwater from the introduction of oxidants and nutrient feed gases into the bioventing bioactive zone of the subsurface, the oxygen and nutrient inputs to the bioactive zone can be adjusted (or carbureted) and controlled independently from the hydrocarbon input to the bioactive zone to achieve good kinetic performance in the bioactive zone while avoiding the problems of plugging of groundwater sparging due to biofilm and precipitate formation.

Abstract: A method for in-situ dense non-aqueous phase liquids treatment in which a subsurface source area comprising at least one rapid release contaminant is located and free water removed therefrom. The subsurface source area is then heated to a temperature suitable for extracting the at least one rapid release contaminant from the subsurface source area. The at least one rapid release contaminant is extracted from the subsurface source area, resulting in solidification of the dense non-aqueous phase liquids remaining in the subsurface source area.

Abstract: A method and device for measuring release rates of contaminants in at least one of a fast release mode and a slow release mode in which a volatile liquid sample is introduced into a sealed transparent reactor vessel having at least one sorbent contained within the transparent reactor vessel and a separator for preventing direct contact between the at least one adsorbent and the at least one volatile liquid sample in the transparent reactor vessel, whereby substantially zero headspace is maintained within the transparent reactor vessel. At least one solvent soluble constituent present in the at least one volatile liquid sample is passed through the separator, resulting in sorption of the at least one solvent soluble constituent by the at least one sorbent. In accordance with one preferred embodiment, the separator is a dialysis bag contained in the transparent reactor vessel into which the resin is placed.

Abstract: A method for identifying and characterizing contaminated sources in a site having contaminated soils and sediments in which vapor pressure is measured at a plurality of subsurface soil sampling locations of the site, which measurements are then mapped, resulting in generation of a subsurface vapor pressure map. Contaminant mobility at the subsurface soil sampling locations having a peak vapor pressure is then determined and contaminants in fast release compartments and slow release compartments in the contaminated soils and sediments identified. Thereafter, the fraction of contaminants in the fast release compartments and the slow release compartments is determined. Calibration of the contaminant-specific vapor pressure with laboratory measurements of the rapid release fraction at each site allows a meaningful and rapid estimation of the spatial location and mass distribution of source areas.

Abstract: A method for identifying and characterizing contaminated sources in a site having contaminated soils and sediments in which vapor pressure is measured at a plurality of subsurface soil sampling locations of the site, which measurements are then mapped, resulting in generation of a subsurface vapor pressure map. Contaminant mobility at the subsurface soil sampling locations having a peak vapor pressure is then determined and contaminants in fast release compartments and slow release compartments in the contaminated soils and sediments identified. Thereafter, the fraction of contaminants in the fast release compartments and the slow release compartments is determined. Calibration of the contaminant-specific vapor pressure with laboratory measurements of the rapid release fraction at each site allows a meaningful and rapid estimation of the spatial location and mass distribution of source areas.

Abstract: A process for in-situ remediation of contaminated soil in which at least one treating agent is introduced into the contaminated soil and transported to an underground in-situ treatment zone of the contaminated soil by a foam-based fluid.

Abstract: A non-mixed vertical tower anaerobic digester and anaerobic digestion process provides passive concentration of biodegradable feed solids and microorganisms in an upper portion of a continuous digester volume and effluent withdrawal from the middle to bottom portion of the digester, resulting in increased solids retention times, reduced hydraulic retention times, and enhanced bioconversion efficiency. In addition, due to passive concentration of solids, the non-mixed anaerobic digester accommodates high solids loadings and provides separation of microbial phases within the continuous digester volume to achieve substantially complete bioconversion of biodegradable feedstock components.

Abstract: An improved anaerobic digestion process is provided to enhance the methane content of product gas so that no further processing may be required for utilization as high quality, high Btu gas comprising greater than 90 percent methane. Operating conditions of lowered carbon dioxide influent concentration to the methane production digester and operation of the methane production digester under pressurization achieve high conversion efficiency rates and high methane content product gas. The carbon dioxide produced during the anaerobic digestion may be physically and chemically separated and removed thereby reducing the carbon dioxide content of the product gas.

Abstract: A method is disclosed for the chemical detoxification of anaerobically digested organic sludge containing toxic heavy metals in insoluble form. A quantity of the sludge is transferred from a conventional anaerobic digester to an insulated reactor vessel where the sludge is mixed and aerated at a rate sufficient to raise the oxidation reduction potential of the sludge to above +300 mv. and to maintain this condition for a period of 6-12 hours during which the heavy metals are converted to their desired oxidation state. The sludge is then acidified under controlled conditions to pH 1.0-3.0 for a period of 6-12 hours to solubilize the heavy metals. Conventional dewatering techniques are used to separate the detoxified, acidic sludge and the acidic, heavy-metal-containing water. The sludge may be neutralized for safe land application, and the metals can be recovered from the water using existing conventional techniques.

Abstract: A method is disclosed for the combined biological-chemical detoxification of municipal sewage sludge. A slurry of thickened primary sludge and secondary waste-activated sludge is fed to an enclosed insulated reactor vessel. The slurry is aerated with ambient air by a self-aspirating aerator to achieve autoheating of the slurry to thermophilic temperatures by the conservation of the metabolic heat of microbiological oxidation of the biodegradable organic material present in the slurry. The slurry is retained in the reactor for a period of time sufficient to destroy pathogenic bacteria and to increase the oxidation reduction potential of the biological reactor contents for the conversion of heavy metals to their desired oxidation state, following which the autoheated slurry is acidified to pH 1.0-3.0 for 6 to 12 hours to solubilize the heavy metals. Conventional dewatering techniques are used to separate the detoxified, acidic sludge and the acidic, heavy-metal-containing water.