Abstract: A process is disclosed for recovering cyanide used to leach gold or silver from ore. In the course of leaching gold or silver from ore, a barren solution is generated. A portion of the barren solution containing sodium cyanide is recycled to the cyanidation process while blowdown from the barren solution is subjected to pre-treatment, UV photodissociation and pH adjustment. Ultimately, a volatile hydrocyanic acid is formed and is absorbed into a sodium hydroxide solution through the employment of a gas-filled membrane. This forms sodium cyanide that can be recycled and used in the cyanidation process to leach gold or silver from ore.

Abstract: A carrier element (1; 10; 20) for growth of biofilm thereon is designed for free-flowing in liquid to be purified and has surfaces (3; 13) for biofilm growth which are protected from the abrasion from other carrier elements or surfaces in a container containing the liquid to be purified by ridges (4; 12) having a height corresponding to a desired thickness of a biofilm intended to grow on the protected surfaces (3; 13). The ratio between the surfaces (3; 13) for biofilm growth and the area of the ridges ranges from 1:1 to 1:20.

Abstract: Apparatus and process is provided for hydrolyzing sludge from water treatment and for conditioning the hydrolyzed sludge for optimal anaerobic digestion. Methods provided include dewatering to produce dewatered sludge, hydrolyzing the dewatered sludge in a steam fed process, preheating the dewatered sludge before hydrolysis with sludge-to-sludge heat transfer, and cooling and diluting the sludge using sludge-to-water heat transfer and water injection, and anaerobically digesting the hydrolyzed sludge. Apparatus provided includes a generally vertically oriented counterflow sludge-to-sludge heat exchanger, a hydrolysis reactor and associated source of steam, sludge-to-water heat exchangers, and a dilution unit. Temperature and pressure sensors are configured to command various variable flow pumps and valves for controlling the process.

Abstract: An amperometric sensor circuit for measuring chlorine concentration in water. The circuit includes first and second working electrodes coated with a hydrophilic membrane. A power supply and biasing circuit is configured to deliver a generally constant voltage between the first working electrode and a reference electrode and to generally deliver a constant current between the second working electrode and a counter electrode. A measurement circuit measures the current between the counter electrode and the first working electrode. A processing circuit is provided for determining the chlorine concentration based on the current measured by the measurement circuit.

Abstract: A method for treating wastewater using a ballasted flocculation technique includes continuously measuring the concentration of suspended solids, organic matter or other impurities in the water to be treated prior to directing the water to be treated to a flocculation tank. Based on this measurement, the amount of ballast necessary to obtain treated water of a predetermined quality is then calculated. In the flocculation tank, ballast and a flocculating reagent are added to the water to form a water-floc mixture. The water-floc mixture is directed to a settling tank where a sludge-ballast mixture is settled. The sludge-ballast mixture is directed to a mixing tank and then to a separator to separate the ballast from the sludge. The separated ballast is directed to the flocculation tank. The separated sludge is directed to the mixing tank when the level of sludge-ballast mixture in the mixing tank is lower than a predetermined level.

Abstract: Method and plant to implement the continuous thermal hydrolysis of sludge to be treated containing organic matter, the method comprising at least: a. a step for de-structuring said sludge to be treated producing de-structured sludge; b. a step for the thermal hydrolysis of said de-structured sludge within a thermal hydrolysis reactor producing hydrolyzed sludge; c. a step for cooling said hydrolyzed sludge; said step for de-structuring consisting in: introducing said sludge to be treated into a dynamic mixer; heating said sludge coming from said dynamic mixer, this heating being obtained by the introduction, into a heat exchanger, on the one hand of said sludge coming from said dynamic mixer and, on the other hand, of said hydrolyzed sludge, this introduction inducing said cooling.

Abstract: The invention is directed to a method of increasing the chemical and/or thermal stability of PHA in biomass where the biomass is contained within mixed liquor, and wherein the mixed liquor is treated by a combination of removing water from the mixed liquor and pH adjustment of the mixed liquor or maintenance of the pH of the mixed liquor within a selected pH range, and wherein the method includes reducing the pH of the mixed liquor below 6, or maintaining the pH of the mixed liquor below 6 for a selected period of time, and wherein the pH adjustment of the mixed liquor to below 6 or the maintenance of the pH of the mixed liquor below 6 gives rise to an increase in chemical and/or thermal stability of the PHA in the biomass.

Abstract: A method of enhancing mechanical properties of compounds formed with polyhydroxyalkanoates (PHA) recovered by biomass where the biomass comprises PHA and non-PHA materials. The method includes dissolving the PHA and non-PHA materials in a solution and separating the PHA and non-PHA materials from the solution. Further, the method includes compounding the separated PHA material and at least some of the separated non-PHA material into a compounded plastic having improved mechanical properties.

Abstract: A degasser includes a vessel having a series of chambers. Liquid containing a gas is directed through the vessel and the chambers therein. A stripping gas is injected into the vessel and moves through the vessel in a counter-current direction relative to the flow of liquid. More particularly, the stripping gas moves from one chamber to another chamber in an upstream direction (relative to the flow of the liquid) and is mixed with the liquid in each chamber, causing gas in the liquid to be displaced. Displaced gas is vented from the vessel at a location near where the liquid enters the vessel.

Abstract: A method of treating primary sludge and activated sludge produced by a wastewater system is disclosed. A portion of the activated sludge is wasted to form biological sludge. The biological sludge is thermally hydrolyzed. The method entails cooling the thermally hydrolyzed biological sludge by mixing primary sludge with the thermally hydrolyzed biological sludge. Thereafter, the combined sludge is directed through a pasteurization process and then to an anaerobic digester which performs anaerobic digestion of the combined sludge.

Abstract: The invention relates to a method for treating water laden with pollutants for the purpose of making the water drinkable, said method including: an elimination step consisting of contacting said water laden with pollutants, within a stirred contact tank (2), with an active particulate material (19) using a predetermined concentration of the active particulate material (19) in said water; an extraction step consisting of continuously extracting from said contact tank (2) a mixture consisting of water and of active particulate material (19); a separation step consisting of continuously separating said active particulate material (19) from said mixture. According to the invention, the separation step consists in particular of feeding the mixture of water and active particulate material into a filter drum (4).

Abstract: The invention pertains to a method for the continuous thermal hydrolysis of sludge to be treated, containing organic matter, said method comprising the steps of simultaneously carrying out the injection of recovered steam into said sludge and mixing said sludge with said recovered steam by means of a primary dynamic injector-mixer so as to obtain a primary uniform mixture; simultaneously carrying out the injection of fresh steam into said primary uniform mixture and mixing said primary uniform mixture with said fresh steam by means of a secondary dynamic injector-mixer so as to obtain a secondary uniform mixture of sludge; conveying said secondary uniform mixture towards a tube reactor under pressure and prompting an essentially plug-type flow of this secondary uniform mixture into said reactor for a residence time that is sufficient and at a temperature that is sufficient to enable the thermal hydrolysis of the organic matter present in this secondary uniform mixture; producing said recovery steam within mea

Abstract: A metalloid contaminated liquid water solution purification process providing decrease to safe human consumption-rated levels of metalloid concentration therein, by precipitation without oxidation and without liquid water heating. The process comprises the following steps: injecting a ferric iron coagulant; injection of lime in the liquid solution; precipitating the metalloid; separating the resulting slurry between a liquid and a solid phase, wherein a clarified water solution is obtained; wherein the liquid phase of the solution is economically reclaimed, while the solid phase slurry is disposed of.

Abstract: A disc filter disposed around a drum for filtering water. The disc filter includes a frame structure and a plurality of filter segments arranged around the drum and secured to the support. Each filter segment includes a filter frame having first and second portions and filter material integrated with the first and second portions of the filter frame through an injection moulding process.

Abstract: Method for the continuous thermal hydrolysis of sludges containing organic matter, said method comprising the steps of: simultaneously injecting pressurized steam (100) into said sludges and mixing said sludges with said steam by means of a dynamic mixer-injector (4) so as to obtain a single-phase mixture, conveying said single-phase mixture towards a tube reactor (4) under pressure and bringing about the plug flow of this mixture into said reactor for a retention time that is sufficient and at a temperature that is sufficient to enable the thermal hydrolysis of the organic matter present in said sludges, cooling said single-phase mixture at its exit from said tube reactor to a temperature enabling the subsequent digestion of the hydrolyzed organic matter that it contains, depressurizing said cooled single-phase mixture.

Abstract: A system and process for treating water wherein water to be treated is directed to an inlet zone and from the inlet zone to a mixing zone. A flotation zone receives water from the mixing zone. A clarified water collection area is disposed adjacent the flotation zone for receiving clarified water from the flotation zone. There is provided one or more spray nozzles disposed in the mixing zone for injecting pressurized water into the mixing zone and generating air bubbles in the mixing zone such that the air bubbles are mixed with the water to be treated. A perforated plate separates the inlet zone and the mixing zone and includes an array of openings through which water to be treated passes as the water to be treated moves from the inlet zone to the mixing zone. The openings in the perforated plate give rise to a homogeneous mixture of the water to be treated and the air bubbles that result from the pressurized water being injected into the mixing zone by the one or more spray nozzles.

Abstract: A method for removing sulfate from a wastewater stream includes mixing gibbsite and a calcium source to precipitate Ettringite from the wastewater stream and produce an effluent with a reduced sulfate concentration. The gibbsite in the precipitated Ettringite is regenerated by mixing an acid with the Ettringite and precipitating gibbsite particles, after which the gibbsite particles are subjected to a crystallization process to increase the size of the gibbsite particles which are recycled back to the main stream.

Abstract: Method for treating water, containing organic matter characterized in that it comprises a step of adsorption of the organic matter contained in said water, in which this water is put into contact with an amagnetic ion-exchanging resin in an infinitely stirred tank (1); the filtering of the mixture of water and resin within the tank (1) and the discharging of filtered water from this tank, the filtering being implemented through at least one screen (4) provided within the tank (1) enabling the resin to be contained in the infinitely stirred tank; the periodic cleansing of the screen (4) consisting of the separation, from this screen, of the saturated resin that has collected thereon; the drawing off (18) of saturated resin from the tank (1); the regenerating (6) of at least a part of the saturated resin thus drawn off; the recycling (7) of said resin thus regenerated in the tank (1); a step of ballasted coagulation/flocculation (12, 13) and separation (14) comprising the addition of coagulant reagent (12b), fl

Abstract: A method and a substance treatment system for reducing a ratio of Glycogen-Accumulating Organisms relative to the total amount of Glycogen-Accumulating Organisms and Polyphosphate-Accumulating Organisms in a substance. A controller for controlling a waste water treatment system in accordance with the method. Use of the method according to control a waste water treatment system in accordance with the method.

Abstract: A ballasted flocculation system that chemically softens water and causes hardness particles to precipitate from the water and crystallize. In the course of crystallizing, the hardness particles grow and form ballasted floc that are separated from the water in the form of sludge by a clarification unit, producing a clarified effluent. The separated sludge including the hardness crystals is directed to a separator where the sludge is separated into two streams with each stream having hardness crystals contained therein. In one process design, one stream includes relatively small hardness crystals and the other stream includes relatively large hardness crystals. The stream having the relatively small hardness crystals is directed to a first reactor and mixed with the incoming water and a softening reagent. The stream having the relatively large crystals is directed to a second downstream reactor and mixed with water and a flocculant which facilitates the growth of the hardness crystals.