Offshore Wastewater Treatment

Abstract

Wastewater is treated on at least one apparatus positioned at a location on the surface of a body of seawater wherein a wastewater intake system takes in wastewater into the apparatus, the wastewater is treated on the apparatus to yield treated wastewater and sludge, and the treated wastewater and/or sludge is diluted with seawater prior to being discharged into the body of seawater. The wastewater treatment systems and methods can also be combined with desalination and/or power generation. In combination with desalination, the concentrate produced from the desalination process is mixed with treated wastewater or sludge prior to discharge to bring the resulting mixture to a salt concentration closer to the body of seawater than the unmixed concentrate, treated wastewater, or sludge. Combustible gases produced by the wastewater treatment process can be used to fuel a power generation system that can be used to produce electrical power for use by systems on the apparatus or transferred off the apparatus for other uses.

1 - 26 . (canceled)  
     
     
         27 : A method of treating wastewater on at least one apparatus positioned at a location on the surface of a body of seawater, the method comprising the steps of: 
 transferring at least about 75 million liters of wastewater per day from a land-based site to the at least one apparatus;    intaking the transferred wastewater into the at least one apparatus; and    treating the wastewater taken into the at least one apparatus to yield end products comprising treated wastewater and sludge; wherein the step of treating the wastewater taken into the at least one apparatus comprises subjecting the wastewater to one or more selected from the group consisting of a membrane-based treatment, filtration through a series of filters having decreasing pore sizes, microfiltration, ultrafiltration, reverse osmosis, chlorination, UV irradiation, mineralization, pH balancing, evaporation vapor compression, electrodialysis, multiple effect distillation, electrodionisation, nanofiltration, molecular sieve treatment, and ultrasonic treatment.    
     
     
         28 : The method of  claim 27 , wherein the step of treating the wastewater taken into the at least one apparatus comprises subjecting the wastewater to two or more selected from the group consisting of a membrane-based treatment, filtration through a series of filters having decreasing pore sizes, microfiltration, ultrafiltration, reverse osmosis, chlorination, UV irradiation, mineralization, pH balancing, evaporation vapor compression, electrodialysis, multiple effect distillation, electrodionisation, nanofiltration, molecular sieve treatment, and ultrasonic treatment.  
     
     
         29 : The method of  claim 27 , wherein the step of treating the wastewater taken into the at least one apparatus comprises subjecting the wastewater to two or more selected from the group consisting of a membrane-based treatment, filtration through a series of filters having decreasing pore sizes, microfiltration, ultrafiltration, reverse osmosis, chlorination, UV irradiation, mineralization, pH balancing, evaporation vapor compression, electrodialysis, multiple effect distillation, electrodionisation, nanofiltration, molecular sieve treatment, and ultrasonic treatment.  
     
     
         30 : The method of  claim 27 , wherein the step of treating the wastewater taken into the at least one apparatus comprises subjecting the wastewater to cloth media filtration.  
     
     
         31 : The method of  claim 27 , wherein the step of treating the wastewater taken into the at least one apparatus comprises subjecting the wastewater to chlorination to yield chlorinated wastewater.  
     
     
         32 : The method of  claim 31 , wherein a chlorine-neutralizing chemical is added to the chlorinated wastewater.  
     
     
         33 : The method of  claim 27 , further comprising the step of contacting the sludge with a microbe killing agent.  
     
     
         34 : The method of  claim 33 , wherein the microbe killing agent is a caustic chemical.  
     
     
         35 : The method of  claim 33 , wherein the microbe killing agent is ultraviolet light.  
     
     
         36 : The method of  claim 27 , further comprising the step of exposing the sludge to an ultrasound treatment.  
     
     
         37 : The method of  claim 36 , further comprising the step of harvesting biogas from the ultrasound treated sludge.