Wastewater treatment systems and methods

Abstract

The instant disclosure is directed towards methods of treating wastewater and related systems, where the system includes: a first zone comprising at least one anaerobic tank, and a second zone comprising at least one engineered wetland. In some embodiments, the system includes a third zone comprising at least one bauxite residue cell.

What is claimed is: 
     
         1 . A method of treating wastewater, comprising:
 flowing a wastewater stream through at least one anaerobic settling and treatment tank, wherein the anaerobic settling and treatment tank comprises:
 a bottom and at least one sidewall, 
 an influent end and an effluent end in liquid communication with a control volume in the tank, wherein the control volume is configured to retain wastewater; 
   wherein the tank further comprises a baffle configuration, including:
 a baffle located adjacent to the influent end and configured to distribute the flow of wastewater into the tank; and 
 at least one member configured between the baffle and the effluent end wall, wherein the member configured to promote mixing and flow distribution of the wastewater, and 
 a settling promoter configured along the effluent end sidewall and configured to promote settling of solids prior to discharge from the effluent end; 
 wherein the baffle configuration is configured to flow wastewater through the tank along at least one predetermined flow path at a surface overflow rate of at least 0.25 m/hr; and 
   treating the wastewater in the anaerobic settling and treatment tank via the baffle configuration and surface over flow rate to remove at least 75% of organics from the wastewater stream to provide a low organics wastewater stream;   flowing a low organics wastewater stream into an engineered wetland from the anaerobic settling treatment tank effluent, wherein the engineered wetland is in liquid communication with the anaerobic settling and treatment tank;   aerating the low organics wastewater stream, wherein aerating the low organics wastewater is sufficient to sustain aerobic bacteria;   treating the low organics wastewater stream in the engineered wetland to remove:
 ammonia from the low organics wastewater to a content of not greater than 8 ppm, wherein the engineered wetland comprises a pore water hydraulic retention time of not greater than 4 days; 
   discharging a treated water stream from the engineered wetland.   
     
     
         2 . The method of  claim 1 , wherein the settling promoter comprises an angle baffle configured to the sidewall proximate an effluent end. 
     
     
         3 . The method of  claim 1 , wherein the settling promoter comprises a discontinuous region along the at least one sidewall proximate an effluent end. 
     
     
         4 . The method of  claim 1 , wherein the anaerobic settling tank comprises a plurality of members spaced apart from one another, between the baffle and the settling promoter. 
     
     
         5 . The method of  claim 4 , further comprising three members, spaced equidistant from each other and comprising the same angled position within the tank, wherein the three members are located proximate to a lower end of the tank. 
     
     
         6 . The method of  claim 1 , wherein aerating comprises aerating the low organics wastewater at a rate of at least 1.1 scfm/gpm wastewater. 
     
     
         7 . The method of  claim 6 , wherein aerating is sufficient to sustain a dissolved oxygen content of at least about 80% of saturation of the low organics wastewater at a given temperature. 
     
     
         8 . The method of  claim 1 , wherein the engineered wetland is comprises a pore water hydraulic retention time of at least about 0.25 day. 
     
     
         9 . The method of  claim 1 , further comprising, prior to the discharging step:
 flowing a low nitrogen wastewater stream from the engineered wetland to an inlet of at least one polishing cell having media including bauxite residue, where the cell is in liquid communication with the engineered wetland, wherein the polishing cell comprises at least one sidewall, an inlet and an outlet configured to encase the media within the cell, wherein the cell is configured to permit the low nitrogen wastewater stream to flow therethrough via the inlet and outlet, and   treating the low nitrogen wastewater via the via the media to remove at least about 30% pathogens from the low nitrogen wastewater; and   flowing a polished water stream from the effluent from the cell.   
     
     
         10 . The method of  claim 1 , further wherein the system comprises a hydraulic retention time of at least 12 hours to not greater than 6 days. 
     
     
         11 . A method comprising:
 analyzing a wastewater stream to determine a contaminant profile, the contaminant profile comprising: at least one contaminant;   selecting a target cleaned water stream profile, wherein the cleaned water stream profile comprises upper limits of the quantities of contaminants present in the contaminant profile; and   selecting, based on the target cleaned water stream profile and the contaminant profile of the wastewater stream, a number of tank modules, based on the contaminant profile;   selecting, based on the target cleaned water stream profile and the contaminant profile of the wastewater stream, a number of engineered wetland modules, based on the contaminant profile;   selecting, based on the target cleaned water stream profile and the contaminant profile of the wastewater stream, a number of bauxite residue modules, based on the contaminant profile;   configuring a wastewater treatment system, where the system comprises a first zone having the number of tank modules, a second zone comprising the number of engineered wetland modules, and a third zone comprising the number of bauxite residue modules to define a wastewater flow path;   flowing the wastewater stream through the flow path defined by the first zone, the second zone, and the third zone of the system;   treating the wastewater via the system to remove contaminants via the first zone, the second zone, and the third zone; and   discharging a cleaned water stream, wherein the cleaned water stream comprises a cleaned water stream profile which corresponds to the target cleaned water stream profile.   
     
     
         12 . The method of  claim 11 , further comprising:
 replacing at least one module of the tank modules, wetland modules, or bauxite residue modules after a predetermined amount of time.   
     
     
         13 . The method of  claim 12 , further comprising:
 replacing at least one module of the tank modules, wetland modules, or bauxite residue modules after a predetermined amount of wastewater has been treated.   
     
     
         14 . The method of  claim 12 , further comprising monitoring at least one module in the wastewater treatment system to assess the effectiveness of the module. 
     
     
         15 . The method of  claim 12 , further comprising moving at least one module via a transport device configured to the module to allow mobility of the module. 
     
     
         16 . The method of  claim 15 , wherein the transport device is selected from the group consisting of: wheels, a track and wheels, a plurality of rollers, a conveyor belt, and combinations thereof. 
     
     
         17 . The method of  claim 11 , connecting the plurality of modules in the system via connection ports as the inlet and outlet. 
     
     
         18 . A method of treating wastewater, comprising:
 flowing a wastewater stream through at least one anaerobic settling and treatment tank, wherein the anaerobic settling and treatment tank comprises:
 a bottom and at least one sidewall, 
 an influent end and an effluent end in liquid communication with a control volume in the tank, wherein the control volume is configured to retain wastewater; 
   wherein the tank further comprises a baffle configuration, including:   a baffle located adjacent to the influent end and configured to distribute the flow of wastewater into the tank; and
 at least one member configured between the baffle and the effluent end wall, wherein the member configured to promote mixing and flow distribution of the wastewater, and 
 a settling promoter configured along the effluent end sidewall and configured to promote settling of solids prior to discharge from the effluent end; 
   wherein the baffle configuration is configured to flow wastewater through the tank along at least one predetermined flow path at a surface overflow rate of at least 0.25 m/hr; and   treating the wastewater in the anaerobic settling and treatment tank via the baffle configuration and surface over flow rate to remove at least 75% of organics from the wastewater stream to provide a low organics wastewater stream;   flowing a low organics wastewater stream into an engineered wetland from the anaerobic settling treatment tank effluent, wherein the engineered wetland is in liquid communication with the anaerobic settling and treatment tank;   aerating the low organics wastewater stream, wherein aerating the low organics wastewater is sufficient to sustain aerobic bacteria;   treating the low organics wastewater stream in the engineered wetland to remove ammonia from the low organics wastewater to a content of not greater than 8 ppm to provide a low nitrogen wastewater stream, wherein the engineered wetland comprises a pore water hydraulic retention time of not greater than 4 days;   flowing the low nitrogen wastewater stream from the engineered wetland to an inlet of at least one polishing cell having media including bauxite residue, where the cell is in liquid communication with the engineered wetland, wherein the polishing cell comprises at least one sidewall, an inlet and an outlet configured to encase the media within the cell, wherein the cell is configured to permit the low nitrogen wastewater stream to flow therethrough via the inlet and outlet, and   treating the low nitrogen wastewater via the via the media to remove at least about 30% pathogens from the low nitrogen wastewater; and   discharging a treated water stream from the engineered wetland.   
     
     
         19 . The method of  claim 18 , further wherein the system comprises a hydraulic retention time of at least 12.5 hours to not greater than 6.5 days.