A method for treating water, comprising:
- intaking a first amount of water into a first plurality of treatment blocks, the first plurality of treatment blocks comprising:
- one or more reverse osmosis treatment blocks, one or more nanofiltration treatment blocks, both a controllable, variable speed, high-pressure pump, and a controllable valve associated with each treatment block of the first plurality of treatment blocks,
- wherein the one or more nanofiltration treatment blocks are in parallel with the one or more reverse osmosis treatment blocks;
- intaking a second amount of water into a blend line that bypasses the first plurality of treatment blocks;
- pre-treating at least the first amount of water using at least one of a filter and a first specially-treated water;
- treating the first amount of water, wherein treating the first amount of water comprises:
- pumping a first portion of the first amount of water through the one or more reverse osmosis treatment blocks of the first plurality of treatment blocks, separating the first portion into a first aqueous stream comprising a first permeate and a second aqueous stream comprising a first concentrate, wherein the first aqueous stream is reduced in monovalent and divalent ions and the second aqueous stream is enriched in monovalent and divalent ions, and
- pumping a second portion of the first amount of water through the one or more nanofiltration treatment blocks of the first plurality of treatment blocks, in parallel with the one or more reverse osmosis treatment blocks, separating the second portion into a third aqueous stream comprising a second permeate and a fourth aqueous stream comprising a second concentrate, wherein the third aqueous stream is reduced in divalent ions and reduced in monovalent ions, while the fourth aqueous stream is enriched in divalent ions and enriched in monovalent ions;
- monitoring each of the first, second, third, and fourth aqueous streams and the fluid from the blend line, wherein the monitoring comprises identifying all of flow rate, conductivity, turbidity, and concentrations of one or more divalent ions for each of the first, second, third, and fourth aqueous streams and the fluid from the blend line;
- controlling an operation of at least one of the first plurality of treatment blocks, by controlling the controllable, variable speed, high-pressure pump, and the controllable valve associated with the at least one of the first plurality of treatment blocks, as a function of predefined water-characteristic tolerances that fall within a predetermined concentration range, wherein controlling comprises modifying at least one of flow rate, pressure, membrane flux, fraction of membranes used, recovery percentage, water pH, and water temperature, and wherein controlling is capable of modifying all of flow rate, pressure, membrane flux, fraction of membranes used, recovery percentage, water pH, and water temperature;
- combining at least two of the first, second, third, and fourth aqueous streams, a second specially-treated water stream, and the fluid from the blend line at a blend point to form a product water stream based on predetermined characteristics of the first, second, third, and fourth aqueous streams, the second specially-treated water stream and the fluid from the blend line and the predefined water-characteristic tolerances;
- outputting the product water stream comprising the combined aqueous streams, wherein the product water stream maintains the predefined water-characteristic tolerances within a predetermined concentration range,
- wherein the second amount of water is a produced water from an oil field recovery operation.