Methods and apparatus for liquid/solid separation for use in applications such as dewatering fine particulate solids, and recovery of valuable metals from ore in a leaching process are provided. One application relates to methods of agitation leaching of metals such as gold from gold-bearing feedstock. A slurry is formed in a tank by agitation, and allowed to settle. A filter bed forms to drain the liquid from the tank, and a vertical screen pipe such as a well point addresses the formation of an impervious film on the upper surface of the filter bed.

Method and apparatus are provided for treating salt water. In the method, a feed water is run through a skimmer unit to form de-oiled water. The de-oiled water is passed through an electrocoagulation unit to form electrocoagulated water. A precipitating agent is added to the electrocoagulated water and stirred to form a water/floc mixture. A polymeric coagulation enhancing agent is added to the water/floc mixture with mild stirring and coagulants in the mixture are permitted to settle. A partly clarified water from the mixture is drawn out from a level above the settled coagulants. The partly clarified water is run through at least one settler and coagulants are removed from the bottom of the at least one settler. A clarified salt water stream is withdrawn from the final settler. The necessary equipment can be mounted on a trailer. The trailer can be provided with a stairway and catwalk to facilitate safe inspection.

Tertiary wastewater treatment wherein a tank is divided into a primary separation chamber, an aerobic chamber, and a clarifier chamber. Media are preferably disposed in the aerobic chamber and most preferably, the media can be contained in one or more porous containers. A recirculation path is preferably provided between the aerobic chamber and the primary separation chamber. In one embodiment, the recirculation between the two chambers can be powered by an air lift pump.

An air intake separator system includes a plurality of vanes adapted to remove fluid or precipitation from an air stream, wherein the vanes are operably coupled to tubular rods with an interference fit. Applying an elevated temperature heat transfer fluid to the plurality of vanes removes fluid or precipitation from an air stream in order to prevent ice formation. Likewise, applying a lower temperature heat transfer fluid can cool the vanes.

A mobile flocculation and water treatment system includes at least one tank, preferably a series of adjoining tanks separated by weirs, and an adjacent pump house mounted on a mobile platform. At least one pump is mounted in the pump house. Fluid conduits run from the pumps to the tank. An overflow is mounted between the downstream tank and the pump house whereby fluid overflow from the tanks is directed into the pump house. The pump house provides a substantially water-tight reservoir zone to provide secondary containment. Water to be treated enters the upstream end of the tanks and is discharged from the downstream end.

An ecological biowater purification system includes at least one water purification tank, each water purification tank including a water inlet, a water outlet, a water purification device, a suction device, a first backflow device and a second backflow device. In particular, the water purification device includes, in order, a sedimentation pool, an anaerobic pool, an anoxic pool, a level-1 and a level-2 biological filter pool, which communicate with one another via baffle boards and communication holes. Each suction device includes a plurality of suction nozzles and suction pipes for discharging precipitates out of the respective water purification tanks. The first backflow device is used to make some water in the level-2 biological filter pool flow back to the sedimentation pool, and the second backflow device is used to make some water in the level-1 and level-2 biological filter pools flow back to the anaerobic pool.

A variable geometry infeed shelf (23) is configured to be installed within a tank pump (1) and provides supplemental internal rigid stationary fluid boundary surfaces within a cylindrical tank assembly (7) of the tank pump (1). The variable geometry infeed shelf (23) promotes uniform distribution of feeding flow around the entire volume of the tank, favouring retention time and reducing bypassing and local peak vertical velocities of a tank infeed flow path (45) in a vertical direction (Z.sub.1) within the tank assembly (7). By virtue of its design, the variable geometry infeed shelf (23) reduces stagnation zones, air entrainment and turbulence within the tank assembly (7), thereby improving pumping efficiency of a centrifugal pump (20) operating within the tank assembly (7).

Methods and apparatus for liquid/solid separation for use in applications such as dewatering fine particulate solids, and recovery of valuable metals from ore in a leaching process are provided. One application relates to methods of agitation leaching of metals such as gold from gold-bearing feedstock. A slurry is formed in a tank by agitation, and allowed to settle. A filter bed forms to drain the liquid from the tank, and a vertical screen pipe such as a well point addresses the formation of an impervious film on the upper surface of the filter bed.

A mobile flocculation and water treatment system includes at least one tank, preferably a series of adjoining tanks separated by weirs, and an adjacent pump house mounted on a mobile platform. At least one pump is mounted in the pump house. Fluid conduits run from the pumps to the tank. An overflow is mounted between the downstream tank and the pump house whereby fluid overflow from the tanks is directed into the pump house. The pump house provides a substantially water-tight reservoir zone to provide secondary containment. Water to be treated enters the upstream end of the tanks and is discharged from the downstream end.

The present disclosure is directed toward a suction nozzle operable to remove solid contaminants from a fluid without causing a substantial increase in fluid resistance. The suction nozzle has a vertical flow path, a contaminant precipitation recess opened upward under the vertical flow path, and a lateral flow path extending laterally from the vertical flow path at a position above the contaminant precipitation recess. The fluid sucked from a suction opening in the lower surface is led to the vertical flow path through the lateral flow path and flows upward through the vertical flow path to reach a connection port. With fluid flowing through the vertical flow path, solid contaminants contained in the fluid settle down by gravity and precipitate in the contaminant precipitation recess and are separated and removed from the fluid.