Method of Treating High Strength Wastewater by Anaerobic Bio Reactor

Abstract

We provide methods, systems, and apparatus for treatment of high chemical oxygen demand wastewater using anaerobic treatment with ceramic membranes. We also provide post-treatment using microbial fuel cells.

1 . A method of treating waste water including biodegradable compounds, comprising:
 feeding wastewater to an anaerobic reactor;   operating the anaerobic reactor at a substantially constant temperature range to produce a mixed liquor including suspended solids and wastewater;   feeding the mixed liquor to at least one ceramic membrane to separate suspended solids and wastewater, thereby producing a purified water stream.   
     
     
         2 . The method of  claim 1 , further comprising continuously stirring the anaerobic reactor during the step of feeding wastewater. 
     
     
         3 . The method of  claim 1 , wherein the substantially constant temperature range is between 20° C. and 45° C. 
     
     
         4 . The method of  claim 3 , wherein the substantially constant temperature range is between 36° C. and 38° C. 
     
     
         5 . The method of  claim 1 , wherein the substantially constant temperature range is between 56° C. and 58° C. 
     
     
         6 . The method of  claim 2 , wherein the continuous stirring is conducted through a hydraulic mixer. 
     
     
         7 . The method of  claim 6 , wherein a hydraulic mixer nozzle accommodates a high velocity of up to 14 m/sec. 
     
     
         8 . The method of  claim 1 , wherein the at least one ceramic membrane is selected from the group consisting of an ultrafiltration ceramic membrane and a microfiltration ceramic membrane. 
     
     
         9 . The method of  claim 1 , wherein the ceramic membrane is operated at a cross flow velocity of 1.5-4.0 m/sec 
     
     
         10 . The method of  claim 1 , wherein the ceramic membrane is operated at flux between 15 to 100 lmh. 
     
     
         11 . The method of  claim 1 , further comprising cleaning the ceramic membrane using backwash to retain flux at the substantially constant temperature range. 
     
     
         12 . The method of  claim 1 , further comprising chemical cleaning the ceramic membrane by circulating a solution of sodium hypochlorite, sodium hydroxide, hydrochloric acid and citric acid through the ceramic membrane. 
     
     
         13 . A method for post-treatment conditioning of wastewater conditioned by an anaerobic process, comprising:
 feeding product water from an anaerobic membrane bioreactor to a microbial fuel cell, wherein the microbial fuel cell comprises graphite electrodes and a heterogeneous cation exchange membrane.   
     
     
         14 . The method of  claim 13 , wherein the microbial fuel cell includes both a high oxidation-reduction potential zone and a low oxidation-reduction potential zone separated by heterogeneous cation exchange membrane. 
     
     
         15 . The method of  claim 14 , wherein an anaerobic outlet of the anaerobic membrane bioreactor feeds to the low oxidation-reduction potential zone of the microbial fuel cell. 
     
     
         16 . The method of  claim 14 , wherein an air and water mixture is fed to the high oxidation-reduction potential zone. 
     
     
         17 . The method of  claim 16  further comprising generating voltage due to a potential difference between high oxidation-reduction potential zone and a low oxidation-reduction potential zone in the microbial fuel cell following degradation of chemical oxygen demand in the low oxidation-reduction potential zone. 
     
     
         18 . A method of treating waste water including biodegradable compounds, comprising:
 feeding wastewater to an anaerobic reactor; and   feeding the wastewater to at least one ceramic membrane to separate suspended solids and wastewater, thereby producing a purified water stream.   
     
     
         19 . An apparatus carrying out a method of  claim 1 .