Water treatment and reuse system

Abstract

System and methods are disclosed for filtering wastewater. In one embodiment, a water filtering system comprises a first filtering stage and a second filtering stage. The first filtering stage receives a flow of wastewater, and uses electrocoagulation to separate suspended particles from the wastewater and produce filtered wastewater. The second filtering stage receives the filtered wastewater from the first filtering stage, and uses mechanical filtering to remove suspended particles from the filtered wastewater and produce filtered water that is substantially free from suspended particles.

I claim: 
     
         1 . An apparatus comprising, comprising:
 a water filtering system for filtering wastewater that uses electrocoagulation, the water filtering system comprising:
 a pre-filtering stage that receives the wastewater, and substantially removes oil from the wastewater before electrocoagulation; 
 a first filtering stage including:
 an electrocoagulation system that receives the wastewater from the pre-filtering stage at its bottom, and injects a current through the wastewater as the wastewater flows up through the electrocoagulation system and out its top; and 
 at least one tank that receives the wastewater from the electrocoagulation system through a gravity flow, and temporarily stores the wastewater to allow suspended particles separate from the wastewater and fall to a bottom of the at least one tank; and 
 
 a second filtering stage that receives the filtered wastewater from the at least one tank, and uses at least one mechanical filter to remove suspended particles from the filtered wastewater. 
   
     
     
         2 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes an oil separator. 
 
     
     
         3 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes an oil skimmer. 
 
     
     
         4 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes a dissolved-air flotation clarifier. 
 
     
     
         5 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes a vacuum clarifier. 
 
     
     
         6 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes an atmospheric clarifier. 
 
     
     
         7 . The apparatus of  claim 1  wherein:
 the pre-filtering stage includes an incline clarifier. 
 
     
     
         8 . The apparatus of  claim 1  wherein:
 the at least one mechanical filter has a pore size down to 0.5 microns. 
 
     
     
         9 . The apparatus of  claim 1  wherein the water filtering system further comprises:
 a third filtering stage that receives the filtered water from the second filtering stage, and removes dissolved particles from the filtered water to produce filtered water that is substantially free from dissolved particles. 
 
     
     
         10 . The apparatus of  claim 9  wherein:
 the third filtering stage uses reverse osmosis to remove the dissolved particles from the filtered water. 
 
     
     
         11 . A method of filtering wastewater, the method comprising:
 receiving wastewater in a pre-filtering stage;   substantially removing oil from the wastewater in the pre-filter stage before electrocoagulation in a subsequent filtering stage;   after the pre-filtering stage, passing the wastewater through an electrocoagulation system that injects a current in the wastewater, wherein the wastewater enters a bottom of the electrocoagulation system and flows up through the electrocoagulation system and out its top;   gravity feeding the wastewater from the electrocoagulation system to at least one tank;   temporarily storing the wastewater in the at least one tank to allow suspended particles to separate from the wastewater and fall to the bottom of the at least one tank; and   passing the filtered wastewater from the at least one tank through at least one mechanical filter to remove suspended particles from the filtered wastewater.   
     
     
         12 . The method of  claim 11  wherein:
 the pre-filtering stage includes an oil separator. 
 
     
     
         13 . The method of  claim 11  wherein:
 the pre-filtering stage includes an oil skimmer. 
 
     
     
         14 . The method of  claim 11  wherein:
 the pre-filtering stage includes a dissolved-air flotation clarifier. 
 
     
     
         15 . The method of  claim 11  wherein:
 the pre-filtering stage includes a vacuum clarifier. 
 
     
     
         16 . The method of  claim 11  wherein:
 the pre-filtering stage includes an atmospheric clarifier. 
 
     
     
         17 . The method of  claim 11  wherein:
 the pre-filtering stage includes an incline clarifier. 
 
     
     
         18 . The method of  claim 11  further comprising:
 removing dissolved particles from the filtered water to produce filtered water that is substantially free from dissolved particles. 
 
     
     
         19 . The method of  claim 18  wherein removing dissolved particles comprises:
 removing the dissolved particles using reverse osmosis. 
 
     
     
         20 . A water filtering system, comprising:
 a separation means for removing hydrocarbons from wastewater;   an electrocoagulation system that receives the wastewater at its bottom from the separation means, and injects a current through the wastewater through a pair of electrodes as the wastewater flows up through the electrocoagulation system and out its top;   at least one tank that receives the wastewater from the electrocoagulation system through a gravity flow, and temporarily stores the wastewater to allow suspended particles in the wastewater to fall to the bottom of the at least one tank; and   at least one mechanical filter that receives the filtered wastewater from the at least one tank, and removes suspended particles from the filtered wastewater.