Systems and methods for water filtration

Abstract

A water filtration systems may comprise an under the sink RO water filtration system that is plumed into a building's water supply. For example, the water filtration systems may include an RO device at least partially installed underneath a sink, with the tap water connection plumbed directly to the sink cold water supply line, and a waste water drain line connected directly to the sink drain, such as the p-trap.

That which is claimed is: 
     
         1 . A reverse osmosis water treatment system, comprising:
 a source of water;   a first three-way valve comprising a first inlet, a second inlet, and an outlet, wherein the first inlet of the first three-way valve is in fluid communication with the source of water;   a filter system comprising an inlet, a first outlet, and a second outlet, wherein the inlet of the filtration system is in fluid communication with the outlet of the first three-way valve, wherein the first outlet of the filter system is in fluid communication with the second inlet of the first three-way valve, wherein the first outlet of the filter system supplies waste water from the filter system to the first three-way valve, and wherein the first three-way valve mixes water from the source of water and waste water from the filter system;   a filtered water tank comprising an inlet and an outlet, wherein the inlet of the filtered water tank is in fluid communication with the second outlet of the filter system, wherein the second outlet of the filter system supplies filtered water to the filtered water tank, wherein the outlet of the filtered water tank is in fluid communication with a faucet, and wherein the outlet of the filtered water tank supplies the filtered water to the faucet;   a pump disposed in fluid communication between the first three-way valve and the filter system; and   a second three-way valve disposed in fluid communication between the first three-way valve and the filter system and in fluid communication with a drain, wherein the second three-way valve diverts a first portion of water from the filter system to the first three-way valve, and wherein the second three-way valve diverts a second portion of water from the filter system to the drain.   
     
     
         2 . The system of  claim 1 , further comprising a pressure reducer disposed in fluid communication between the source of water and the first three-way valve. 
     
     
         3 . The system of  claim 1 , wherein the filter system further comprises:
 a first filter and a second filter;   wherein the first filter is configured and disposed to receive water from the inlet of the filter system and to filter and deliver first filtered water to the second filter; and   wherein the second filter is configured and disposed to receive the first filtered water from the first filter, to deliver a first portion of the first filtered water to the first outlet of the filter system, the first portion of the first filtered water being the waste water that is delivered back to the first three-way valve, and to filter and deliver a second portion of the first filtered water, the second portion of the first filtered water being the filtered water.   
     
     
         4 . The system of  claim 3 , wherein the filter system further comprises a third filter, wherein the third filter is configured and disposed to receive the filtered water from the second filter and to further filter and deliver the filtered water to the second outlet of the filter system. 
     
     
         5 . The system of  claim 4 , wherein:
 the first filter comprises a sediment filter, a carbon filter, a KDF filter, or a combination thereof;   the second filter comprises a reverse osmosis membrane; and   the third filter comprises a carbon filter, an ion exchange filter, a remineralization element, or a combination thereof.   
     
     
         6 . The system of  claim 4 , wherein:
 100% of the water that enters the first filter passes to the second filter;   less than 100% of the water that enters the second filter passes to the third filter; and   100% of the water that enters the third filter passes to the filtered water tank.   
     
     
         7 . The system of  claim 1 , wherein:
 about 75% of the waste water from the filter system is supplied to the first three-way valve by way of the second three-way valve as the first portion of the water from the filter system; and   about 25% of the water from the filter system is diverted by way of the second three-way valve as the second portion of water from the filter system to the drain.   
     
     
         8 . A reverse osmosis water treatment system, comprising:
 a source of water;   a first three-way valve comprising a first inlet, a second inlet, and an outlet, wherein the first inlet of the first three-way valve is in fluid communication with the source of water;   a filter system comprising an inlet, a first outlet, and a second outlet, wherein the inlet of the filtration system is in fluid communication with the outlet of the first three-way valve, wherein the first outlet of the filter system is in fluid communication with the second inlet of the first three-way valve, wherein the first outlet of the filter system supplies waste water from the filter system to the first three-way valve, and wherein the first three-way valve mixes water from the source of water and waste water from the filter system;   a pump disposed in fluid communication between the first three-way valve and the filter system; and   a second three-way valve disposed in fluid communication between the first three-way valve and the filter system and in fluid communication with a drain, wherein the second three-way valve diverts a first portion of water from the filter system to the first three-way valve, and wherein the second three-way valve diverts a second portion of water from the filter system to the drain.