High Efficiency Water Purification System

Abstract

A high efficiency water purification system is provided incorporating a process to recover a portion of the concentrate wastewater associated with the reverse osmosis unit to reduce the overall volume of concentrate wastewater requiring discharge/disposal by reusing the purified concentrate of a concentrate recovery units as RO feed water. The initial municipal feedwater is pressurized and passed through an RO membrane, and separated into a permeate flow and a concentrate flow. After passing through the membrane, a portion of the higher pressure concentrate is then directed to an additional set of thin film composite membranes (concentrate recovery membranes). The concentrate is drawn from the primary RO unit upstream of a concentrate flow control valve where the pressure is typically 100-600 psig. The concentrate recovery membranes are arranged in an array such that the concentrate pressure is adequate to provide the force required to drive the concentrate through the recovery system membranes. The permeate produced by the concentrate recovery system is directed back to the feed of the primary RO unit; thereby, reducing the volume of raw feed water required for system operation. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

1 . A water purification systems comprising:
 a feedwater source;   a primary reverse osmosis unit treating a first input and having a first permeate discharge and a first concentrate discharge;   at least one concentrate recovery unit in fluid communication with said first concentrate discharge in which at least a portion of said concentrate discharge is further separated into a second permeate discharge and a second concentrate recovery;   
       wherein both said second concentrate recovery and said feedwater source are in fluid communication with said first input; and 
       wherein the combination of said first permeate recovery and said second permeate recovery is capable of continuous recovery of at least 80% of said feedwater source. 
     
     
         2 . The water purification system of  claim 1 , wherein said feedwater source is selected from the group consisting of: municipal water sources; industrial water sources; and tertiary water sources. 
     
     
         3 . The water purification system of  claim 2 , wherein said primary reverse osmosis unit comprises at least one thin film recovery membrane. 
     
     
         4 . The water purification system of  claim 3 , further comprising:
 said concentrate recovery unit comprising a plurality of composite reverse osmosis membrane modules arranged in parallel, and   each said module having a permeate discharge in combination with each other and forming said second permeate discharge, and wherein each module further has a concentrate discharge in combination with each other and forming said second concentrate discharge;   
       wherein said first concentrate discharge is in driven in fluid communication with said concentrate recovery unit with the urging force of the concentrate pressure of said primary reverse osmosis unit and without the input of additional energy. 
     
     
         5 . The water purification system of  claim 3 , wherein said concentrate recovery unit further comprises at least one additional reverse osmosis stage in series for separating the collected permeate form said plurality of composite reverse osmosis membrane modules arranged in parallel. 
     
     
         6 . The water purification system of  claim 5 , wherein said additional reverse osmosis stage further comprises a plurality of additional reverse osmosis elements. 
     
     
         7 . A water purification systems of  claim 1 , wherein said primary reverse osmosis unit is operated at a pressure in the range of 200-400 psig. 
     
     
         8 . The water purification system of  claim 7 , wherein said concentrate recovery is operated at a pressure in the range of 200-300 psig. 
     
     
         9 . The water purification system of  claim 2 , wherein said feedwater source is pre-treated by filtering and otherwise removing materials known to be detrimental to RO membrane operation. 
     
     
         10 . The water purification system of  claim 1 , wherein said concentrate recovery system is adapted to be capable of retrofit onto existing RO installations. 
     
     
         11 . A process to recover a portion of the concentrate wastewater associated with the reverse osmosis unit for reducing the overall volume of concentrate wastewater requiring discharge/disposal by reusing the purified concentrate of a concentrate recovery units as RO feed water, said process comprising:
 a. obtaining an initial feed water inlet;   b. pressurizing said feedwater and passed said feedwater through a thin film composite reverse osmosis membrane to create a separate first permeate flow and a first concentrate flow;   c. directing said first concentrate flow to an additional set of thin film composite membranes (concentrate recovery membranes), wherein said concentrate recovery membranes are arranged in an array such that the concentrate pressure is adequate to provide the force required to drive the concentrate through the recovery system membranes; and   d. directing the permeate produced by the concentrate recovery system back to the feed of the primary RO unit;   
       thereby, reducing the volume of raw feed water required for system operation. 
     
     
         12 . The process of  claim 11 , wherein said first concentrate is drawn from the primary RO unit upstream of a concentrate flow control valve at a pressure between 100-600 psig. 
     
     
         13 . The process of  claim 12 , wherein a concentrate flow rate is controlled by a second flow control valve and is discharged as a wastewater. 
     
     
         14 . The process of  claim 13 , wherein said concentrate recovery system is operated at between 30-60% recovery depending on the feed water characteristics as limited by sparingly soluble salts which can foul the reverse osmosis membranes. 
     
     
         15 . The process of  claim 14 , wherein said concentrate recovery unit utilizes pressure that is available as part of the normal operating parameters of the primary RO unit such that additional energy is not required for the recovery process. 
     
     
         16 . The process of  claim 11 , wherein said feedwater is selected from the group consisting of: a municipal water source; an industrial water source; and a tertiary water source. 
     
     
         17 . The process of  claim 16 , wherein said feedwater is pre-treated by filtering and otherwise removing materials detrimental to RO membrane operation. 
     
     
         18 . The process of  claim 11 , adapted to be retrofitted onto existing RO installations.