Formation of CaSO.sub.4 and Fe.sub.2O.sub.3 containing deposits is reduced in a pressure oxidation autoclave and/or adjacent circuits during pressure oxidation of gold-containing ore. The gold-containing ore is combined with water to create an aqueous slurry that is heated and introduced into the autoclave. The method includes providing a scale inhibitor that is free of an organic polymer and includes an inorganic phosphate according to formula (I), (XPO.sub.3).sub.m, wherein X is Na, K, H, or combinations thereof, and m is at least about 6, an inorganic phosphate according to formula (II), Y.sub.n+2P.sub.nO.sub.3n+1, wherein Y is Na, K, H, an organic phosphonate; or combinations thereof, and n is at least about 6. The method includes the step of combining the scale inhibitor and at least one of the gold-containing ore, the water, and the aqueous slurry to reduce scale.

Provided are hybrid electrochemical and membrane-based systems for removing silica from water stream to achieve ultra-pure water. The silica concentration of a feed water stream may dictate the most effective and economical variation of disclosed hybrid processes to use. For example, for a feed water stream having a silica concentration of 1-30 ppm, a hybrid system for treating the feed water includes an electrodialysis reversal unit, the electrodialysis reversal unit comprising an inlet stream and a product outlet stream; a reverse osmosis unit, the reverse osmosis unit comprising an inlet stream and a product outlet stream, wherein the inlet stream of the reverse osmosis unit comprises the product outlet stream of the electrodialysis reversal unit; and an electrodeionization unit, the electrodeionization unit comprising an inlet stream and a product outlet stream, wherein the inlet stream of the electrodeionization unit comprises the product outlet stream of the reverse osmosis unit.

A liquid-cooling heat dissipation system capable of regulating water quality includes a first liquid inlet, a first liquid outlet, a heat exchange unit, a sensation unit, a water quality regulating unit for containing and releasing an agent and a control unit. The heat exchange unit has a heat exchanger, a first pump and a mating opening connected with the water quality regulating unit. The sensation unit detects the pH value of a first working liquid and transmits a sensation signal to the control unit. The control unit compares the sensation signal with a preset pH value range to generate and transmit a comparison result to an external interface, whereby the water quality regulating unit is manually controlled to release the agent or not. Alternatively, according to the comparison result, the control unit automatically controls the water quality regulating unit to release the agent or not.

The present invention belongs to the technical field of wastewater treatment, and particularly relates to a method for pre-conditioning high-calcium wastewater by calcification blocking, and a device for implementing the method. The method for treating high-calcium wastewater by calcification blocking includes mixing high-calcium wastewater, an alkalizing agent and a chelating agent, and carrying out alkalizing conditioning pretreatment under a condition of stirring by bubbling of a biogas, so as to obtain pre-conditioned wastewater. The pre-conditioned wastewater is mixed with anaerobic granular sludge, and an anaerobic reaction is performed in a high hydraulic shear flow field formed by the biogas, so as to generate the biogas and calcium scale. A part of the biogas for the stirring is refluxed by bubbling of the biogas and the rest of the biogas is refluxed for forming the high hydraulic shear flow field.

A process for removing silica and reducing total hardness of a natural or waste water containing silica and scale-forming ions comprises adding (i) magnesium hydroxide or a precursor of magnesium hydroxide and (ii) a soluble aluminate compound or a precursor of aluminate to said water while maintaining the pH of said stream at pH>8 to produce a layered double hydroxide in situ, wherein the layered double hydroxide contains the scale-forming ions in a lattice of the layered double hydroxide and silica is incorporated in the lattice of the layered double hydroxide as an interlayer anion and/or bound by the layered double hydroxide via one or more binding modes, wherein the process further comprises a recycling and regeneration step and/or a hydroxide addition step.

The invention relates to a water filter cartridge comprising a housing and a filter-side tank connection element for insertion into a water tank, more particularly into a water tank of a household appliance (11), and a filter section for treating the water to be taken from the water tank. It is distinguished by the fact that the water filter cartridge comprises a reservoir chamber with a means to counter precipitations in the water tank, where the reservoir chamber is designed separate from the filter section and its flow guideway for the water running through the filter section to be treated, in such a way that there is no contact between the water flowing through the filter section and the means to counter precipitations, and that the reservoir chamber has at least one passage for the means, whereby the means to counter precipitations is in contact with the unfiltered water in the water tank.

Disclosed are methods and compositions for coagulating and clarifying produced waters for use as boiler feed waters, for example for the generation of steam. The methods and compositions are especially useful for treatment of produced waters from steam-injection methods of tertiary oil recovery such as steam-assisted gravitational drainage. Disclosed are compositions comprising a first copolymer having a high molecular weight and bearing a low molar cationic charge and a second copolymer having a lower molecular weight and bearing a high molar cationic charge. The compositions are suitable for addition as coagulants to produced waters that have been treated by warm lime softening. Also disclosed are methods of treating produced waters from steam-injection oil recovery for use as boiler feed waters to generate steam in such steam injection methods.

Disclosed are methods and compositions for coagulating and clarifying produced waters for use as boiler feed waters, for example for the generation of steam. The methods and compositions are especially useful for treatment of produced waters from steam-injection methods of tertiary oil recovery such as steam-assisted gravitational drainage. Disclosed are compositions comprising a first copolymer having a high molecular weight and bearing a low molar cationic charge and a second copolymer having a lower molecular weight and bearing a high molar cationic charge. The compositions are suitable for addition as coagulants to produced waters that have been treated by warm lime softening. Also disclosed are methods of treating produced waters from steam-injection oil recovery for use as boiler feed waters to generate steam in such steam injection methods.

A phosphorus-based calcification inhibitor (inhibitor) configured to prevent calcification of anaerobic granular sludge.

Produced water from a crude oil or natural gas production process is purified using a membrane purification system for petroleum production, agricultural, commercial and domestic uses. The produced water is pretreated to remove, at least, particulates and oil from the produced water. The minimally pretreated water is then purified in a membrane purification system, that is operated at conditions such that membrane scaling is reduced or prevented. In particular, the membrane purification system is operated to maintain the turbidity of clarified water feed to the system or intermediate aqueous streams that are cascading through the membrane purification system. Ensuring that the turbidity of the reject streams generated in the membrane system are useful in achieving long membrane operating life.