Treatment plant for processing animal wastes produced in a confined animal growing are

Abstract

Noxious odors and water pollution commonly associated with the raising of hogs, cattle or poultry under confined conditions are eliminated by replacing the conventional waste lagoon and waste spreading fields with a wastewater treatment plant. The treatment plant extracts manure from the wastewater, then dries and burns the manure along with collected waste gases. The liquid waste portion is filtered, deodorized and then recirculated to the growing buildings as flushwater.

That which is claimed is:  
     
         1 . A method of processing animal wastes produced in the confined animal growing area of a farm, said method comprising: 
 establishing a wastewater stream comprising flushwater and waste from the confined animal growing area of a farm;    separating manure from the wastewater stream to thereby divide the wastewater stream into a wet manure portion and a liquid portion;    dewatering the wet manure portion;    burning the dewatered manure; and    cleansing the liquid portion and recirculating the so-cleansed liquid portion to the confined animal growing area for use as flushwater.    
     
     
         2 . The method of    claim 1    wherein the separating step comprises screening the wastewater to produce a first amount of wet manure followed by settling solids from the remainder of the wastewater to produce a second amount of wet manure.  
     
     
         3 . The method of    claim 1    including the steps of collecting waste gases produced during the dewatering step and burning the waste gases.  
     
     
         4 . The method of    claim 1    including the steps of collecting waste gases produced during the separating and dewatering steps and burning the waste gases.  
     
     
         5 . The method of    claim 1    comprising utilizing thermal energy produced by incinerating the dewatered manure in the step of dewatering the wet manure.  
     
     
         6 . A method of processing animal wastes produced in the confined animal growing area of a farm, said method comprising: 
 establishing a wastewater stream comprising flushwater and waste from the confined animal growing area of a farm;    holding flushwater and waste from the stream in a liquid/solids raw waste hold tank;    drawing a slurry of liquid and solid waste from the hold tank and separating manure therefrom to divide the slurry into a wet manure portion and a liquid portion;    dewatering the wet manure portion;    burning the dewatered manure;    deodorizing the liquid portion;    storing the deodorized liquid portion in a reservoir;    evaporating part of the reservoir contents; and    recirculating the deodorized liquid portion from the reservoir to the confined animal growing area for use as flushwater.    
     
     
         7 . The method of    claim 6    including the step of utilizing a flushwater loop that recirculates a substantially constant volume of flushwater to which additional water is added in the form of urine, spilled drinking water, washwater, and the like, and wherein the step of evaporating part of the reservoir contents removes sufficient water from the loop to counter water accumulation due to the additional water.  
     
     
         8 . The method of    claim 6    including the step of collecting waste gases produced during the holding, separating and dewatering steps and burning the waste gases.  
     
     
         9 . The method of    claim 8    including the step of condensing out at least a portion of the water content of the waste gases produced during the dewatering step before burning the waste gases.  
     
     
         10 . The method of    claim 6    wherein the animal waste is processed in real time as defined by burning the manure within about twenty-four hours of it being deposited in the raw waste hold tank.  
     
     
         11 . The method of    claim 6    including the step of comminuting the waste slurry between the holding and separating steps.  
     
     
         12 . The method of    claim 6    wherein the evaporator step is carried out by conveying a portion of the reservoir contents to a solar evaporator basin.  
     
     
         13 . The method of    claim 12    including the step of draining the solar evaporator basin to the reservoir during periods of rain.  
     
     
         14 . A wastewater treatment plant for separating manure from the wastewater flushed from the confined animal growing area of a farm and disposing of the manure in an environmentally responsible manner while recirculating the liquid portion of the wastewater to the growing area for reuse as flushwater, said wastewater treatment plant comprising: 
 a separator for receiving wastewater comprising flushwater and animal waste from the confined animal growing area of a farm and dividing the wastewater into a wet manure portion and a liquid portion;    a dryer in communication with said separator for receiving the wet manure portion therefrom and drying the same to an acceptable moisture content for burning;    a combustor in communication with said dryer for receiving manure from the dryer and burning the same; and    means for recirculating the liquid portion from the separator to the confined animal growing area for use as flushwater.    
     
     
         15 . The wastewater treatment plant of    claim 14    including means for cleansing the liquid portion prior to recirculating the liquid for use as flushwater.  
     
     
         16 . The wastewater treatment plant of    claim 15    wherein said means for cleansing comprises ozonation means.  
     
     
         17 . The wastewater treatment plant of    claim 14    including means for collecting gases produced at the separator and dryer and means for conveying the collected gases to the combustor.  
     
     
         18 . The wastewater treatment plant of    claim 17    including a condenser for removing at least a portion of the water content from the gases conveyed from the dryer to the combustor.  
     
     
         19 . The wastewater treatment plant of    claim 14    including a flushwater reservoir for receiving and holding the liquid portion from the separator prior to recirculating the liquid as flushwater.  
     
     
         20 . The wastewater treatment plant of    claim 19    including a solar evaporator having a basin for receiving flushwater from the flushwater reservoir to permit evaporation of a portion of the flushwater.  
     
     
         21 . The wastewater treatment plant of    claim 20    wherein said solar evaporator includes means for draining the evaporator contents back into the flushwater reservoir during periods of rain.  
     
     
         22 . The wastewater treatment plant of    claim 20    including means for using a portion of the thermal energy generated by the combustor to enhance evaporation rates in the evaporator.  
     
     
         23 . The wastewater treatment plant of    claim 14    wherein said separator comprises a primary stage having a screen and a secondary stage having a settling tank.  
     
     
         24 . The wastewater treatment plant of    claim 14    wherein said separator comprises a belt-press filter.  
     
     
         25 . An animal growing farm including: 
 a confined animal growing area;    means at the animal growing area for utilizing flushwater to flush animal waste from the growing area and establishing a wastewater stream comprising flushwater and animal waste;    a raw waste hold tank for holding flushwater and animal waste conveyed thereto by the wastewater stream;    a waste processor for processing the contents of the hold tank by extracting, drying and burning the manure portion and deodorizing the liquid portion, said waste processor comprising: 
 a separator for dividing the contents of the raw waste hold tank into a wet manure portion and a liquid portion;  
 a dryer in communication with said separator for receiving the wet manure portion therefrom and drying the same to an acceptable moisture content for burning;  
 a combustor in communication with said dryer for receiving manure from the dryer and burning the same;  
 a deodorizer in communication with said separator for receiving the liquid portion therefrom and deodorizing the same;  
   a clean flushwater reservoir in communication with the deodorizer for receipt of the deodorized liquid portion and storage of the same; and    a solar evaporator in fluid communication with the clean flushwater reservoir, said solar evaporator including a basin permitting evaporation of a portion of the contents of the reservoir.    
     
     
         26 . The animal growing farm of    claim 25    wherein said waste processor includes a comminuter for comminuting the contents of the waste hold tank before the contents thereof reach the separator.  
     
     
         27 . The animal growing farm of    claim 25    wherein the raw waste hold tank, separator and dryer are covered to capture waste gases produced therein.  
     
     
         28 . The animal growing farm of    claim 27    including means for conveying the waste gases from the raw waste hold tank, separator and dryer to the combustor for burning.  
     
     
         29 . The animal growing farm of    claim 25    wherein the solar evaporator includes means for draining the evaporator contents back into the flushwater reservoir during periods of rain.  
     
     
         30 . A method for converting an existing hog farm of the type having a confined area for growth of hogs, a lagoon and spreading fields to an environmentally sound operation requiring less acreage, said method comprising: 
 installing a wastewater treatment plant at an existing hog farm having a confined area for growth of hogs, said wastewater treatment plant receiving a wastewater stream of flushwater and waste that was formerly routed to the lagoon, the wastewater-treatment plant performing the steps of: 
 separating manure from the wastewater stream to thereby divide the wastewater stream into a wet manure portion and a liquid portion;  
 dewatering the wet manure portion;  
 burning the dewatered manure; and  
 cleansing the liquid portion and recirculating the so-cleansed liquid portion to  
   the confined animal growing area for use as flushwater; 
 draining at least a portion of the contents of the discontinued lagoon through the installed wastewater treatment plant at times when excess plant capacity so permits; and  
 discontinuing use of the spreading fields for the receipt of lagoon water so that the spreading fields acreage may be used to expand hog farming operations, used as conventional crop fields, sold to finance the installation of the wastewater treatment plant, or otherwise used as desired by the owner without the necessity of spreading lagoon water thereon.