Separation processes using osmotically driven membrane systems are disclosed generally involving the extraction of solvent from a first solution to concentrate a solute by using a second concentrated solution to draw the solvent from the first solution across a semi-permeable membrane. Pre-treatment and post-treatment may also enhance the osmotically driven membrane processes.

Separation processes using osmotically driven membrane systems are disclosed generally involving the extraction of solvent from a first solution to concentrate a solute by using a second concentrated solution to draw the solvent from the first solution across a semi-permeable membrane. Pre-treatment and post-treatment may also enhance the osmotically driven membrane processes.

Disclosed herein is a system for cleaning feed water of variable quality, the system including an inlet for selectively delivering feed water to one or other of at least two feed chambers, each feed chamber having a delivery pipe for delivering feed water to a reverse osmosis or nanofiltration, a pump to deliver the feed water from one of the chambers through its associated delivery pipe to the reverse osmosis or nanofiltration to create a concentrated feed stream and a product water stream, return pipes for selectively returning the concentrated feed stream to one or another of the at least two feed chambers, a product water outlet for removal of the product water, and switching mechanisms and/or switchers for switching the delivery of the concentrated feed stream between the selectable return pipes upon detection of a predetermined reduction in efficiency within one or another of the feed chambers.

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 contaminants are removed. In particular, the membrane purification system is operated with pH adjustments to allow boron and ammonia to be effectively removed. In some embodiments, greater than 95% of the boron content and greater than 95% of the ammonia content are removed. Some method embodiments include no separate ion exchange separation step capable of removing ammonia.

Disclosed herein is a system for cleaning feed water of variable quality, the system including an inlet for selectively delivering feed water to one or other of at least two feed chambers, each feed chamber having a delivery pipe for delivering feed water to a reverse osmosis or nanofiltration, a pump to deliver the feed water from one of the chambers through its associated delivery pipe to the reverse osmosis or nanofiltration to create a concentrated feed stream and a product water stream, return pipes for selectively returning the concentrated feed stream to one or another of the at least two feed chambers, a product water outlet for removal of the product water, and switching mechanisms and/or switchers for switching the delivery of the concentrated feed stream between the selectable return pipes upon detection of a predetermined reduction in efficiency within one or another of the feed chambers.

A water treatment system is provided. The system includes a prefiltration unit for filtering the untreated water in fluid communication with a source of untreated water. The prefiltration unit produces a prefiltered water from the untreated water. A pump in fluid communication with the prefiltration unit can selectively increase the flow rate of the prefiltered water in a first line, the first line in fluid communication with a membrane element. The membrane element produces a permeate and a retentate from the prefiltered water, the permeate being imparted with a lower concentration of solutes than the retentate. A tank in fluid communication with the membrane element and the prefiltration unit stores prefiltered water from the prefiltration unit and the permeate from the membrane element. One or more valves regulate the flow of prefiltered water and the permeate, and one or more sensors can measure characteristics of the prefiltered water.

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.

The present invention relates to a process for the preparation of an aqueous solution comprising at least one earth alkali hydrogen carbonate, a process for the mineralization and/or stabilization of water as well as the use of the aqueous solution comprising at least one earth alkali hydrogen carbonate obtained by the process for the mineralization and/or stabilization of water.

A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water (FW) to one or other of at least two feed chambers (2,4), each feed chamber having a delivery pipe (2i, 4i) for delivering feed water to a reverse osmosis or nanofiltration (8); a pump (6) to deliver the feed water from one of the chambers (2, 4) through its as sociated delivery pipe (2i, 4i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW);return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concen trated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmo spheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).

A system for cleaning feed water of variable quality, the system comprising an inlet for selectively delivering feed water (FW) to one or other of at least two feed chambers (2,4), each feed chamber having a delivery pipe (2i, 4i) for delivering feed water to a reverse osmosis or nanofiltration (8); a pump (6) to deliver the feed water from one of the chambers (2, 4) through its as sociated delivery pipe (2i, 4i) to the reverse osmosis or nanofiltration (8) to create a concentrated feed stream and a product water stream (PW);return pipes (2R, 4R) for selectively returning the concentrated feed stream to one or other of the at least two feed chambers (2, 4); a product water outlet for removal of the product water (PW); and means for switching the delivery of the concen trated feed stream between the selectable return pipes (2R, 4R) upon detection of a predetermined reduction in the efficiency of the RO or NF process within one or other of the feed chambers (2, 4). The pressure of the concentrated feed stream is reduced to atmo spheric pressure prior to its delivery back to the chamber and the feed stream passes through a desaturation unit (20).