MXPA96005695A - Process for treating residual water resulting from the production of tequila - Google Patents

Abstract

A residual water treatment system which comprises a percolation filter, a unit of activated muds, disposed downstream the percolation filter, and at least disposed downstream of the activated unit, wherein the percolation filter recycles the residual water in a four to one relation or even higher.

Description

PROCESQ TO TREAT RESIDUAL WAS RESULTING FROM THE PRODUCTION OF TEQUILA BACKGROUND OF THE INVENTION This invention relates to the treatment of wastewater and more particularly to a process for treating wastewater resulting from the production of tequila and other alcoholic beverages. The sugars of agave as well as other sugars such as glucose and brown sugar are used as ingredients for ** • make tequila. Yeast can be added to a mixer that houses the various sugars in order to aid the fermentation process. The formulation can then be transferred to fermentation tanks for the production of the alcohol. The fermentation product is then supplied to stills where the alcohol is recovered. During normal operation, a given still is emptied and washed approximately every two hours. The background of The still of the first distillation contains a mixture of 0 unfermented sugars, alcohol, acetic acid, and a yeast dough. Approximately 63 percent of the total wastewater produced by a tequila factory arises from the waste stream of the first distillation. The product from the top of the first distillation passes to a second group of stills to be distilled a second time to then remove the methyl alcohol from the product. The second distillation produces approximately 17 percent of the total residual water in the factory. In some applications, a third distillation is done to further improve the quality of the product. Approximately 16 percent of the 5 wastewater produced by a tequila factory is generated in the washing of the cooking and fermentation tanks and the washing throughout the factory. The remaining 4 percent of wastewater can be the result of sanitary drains in the factory. In addition, the material left by the still is at a temperature of approximately 80 ° C. The current wastewater treatment systems for tequila plants consist of a system of drains to collect the wastewater and transport the wastewater to a collector. From the collector, the water can be pumped into a concrete storage tank to lower the temperature. The wastewater from the storage tank is periodically pumped to one of the lagoons A * which can be located in the back of the tequila factory. Where, for example, several ponds are used, 0 one or more ponds can be used to recover settled solids and subsequently one or more ponds can be used to reduce the remaining insoluble organic matter entering and the matter soluble organic Sedesol, the government agency responsible for water regulation, establishes the standards for the acceptable levels of discharge of the Biological Oxygen Demand (BOD), the Chemical Oxygen Demand (COD), the Total Suspended Solids (TSS), and the pH. It is desirable to have a wastewater treatment process that meets the requirements of Sedesol. In addition, current wastewater treatment systems for tequila factories produce undesirable odors that can be harmful to people living in the vicinity of the tequila factory. It is also convenient to reduce the offensive odors resulting from tequila wastewater.

Brief Description of the Drawings FIGURE 1 is a simplified block diagram of the water treatment system of the present invention. FIGURES 2A and 2B are a schematic view of the wastewater treatment system of the present invention.

Detailed Description of the Preferred Modes With reference to FIGURES 1 and 2, the wastewater treatment system 2 of the present invention is shown, preferably, the wastewater from the factory process runs through a centrifuge, not shown, to remove most of the excess suspended solids from the influent as it is done in the industry. These solids can also be recycled for the fermentation process or used in the manufacture of animal feed or mixed with secondary sludge for disposal as is done in the industry. The waste water can then be stored in a tank of >; storage 4. One or more pumps 8, 10 can pump waste water to an inlet filter 6 via a plurality of valves 12, 13, 14, 15, 16 and 18. Pumps 9, 10 can, for example, pump the wastewater at 6,615 liters per second to the filter 6. Filter 6 removes any remaining c * - suspended solids from the waste water in the storage tank 4. Preferably, more than one pump and valve is provided to serve as backup in the In case a pump or valve fails, as a result, the waste water can be derive by means of a different valve and pump for subsequent treatment. The waste water is then supplied to a pH control system 20. Because the incoming waste water from the filter 6 has a pH level of two to six standard units (SU), and because the wastewater is treated more efficiently when the pH level is 7.0 standard units, it is convenient to raise the pH level of the wastewater to 7.0 standard units. The pH control system 20 comprises a neutralization tank 22, a tank of supply of chemical products and a measuring pump, a pH sensor or analyzer, and a pH controller. The waste concentrate from the first distillation, the wash water, the purge from the second distillation, and the sanitary sewage effluent are supplied to the pH 22 control tank to raise the pH level to 7.0 standard units. As shown in block 23, a hydrous sludge (calcium hydroxide) or a caustic solution (ie, sodium hydroxide) is supplied to tank 22 to produce the pH adjustment. Alternatively, magnesium hydroxide can be used for pH adjustment. A quick mixer 24 is used to mix the hydrated or caustic slime with the waste water. In some applications, the pH control system 20 can be used to raise the pH value to higher levels, such as 8.5 standard units when the phosphorus levels in the influent concentration is high enough to require it. The product of the pH control system is supplied to a compensation tank 30 via a gravity feed valve 32. The compensation tank 30 may have an overflow 31. At the outlet of the gravity feed valve 32, there may be a sample port 34 for examining the waste water and a thermometer 36 for checking the temperature of the waste water. Equalization tank 30 is used to hold residual water to help ensure neutralization of wastewater (ie ensure control of the appropriate pH and phosphor level) and mix the different streams to provide a uniform feed mix for the filters of percolation. A quick mixer or aeration device 38 is used to ensure proper mixing of any chemical additive (ie, caustic or calcium hydroxide) and to partially aerate the waste water to prevent odors. The compensation tank 30 allows a continuous supply of waste water whose pH level has been raised for the percolation filter 72 to be described. The first part of the water treatment (that is, the front end of the treatment plant) encompassing the centrifugation, the storage tank and the associated pumps, the final filtration performed by the filter 6, cooling and pH control carried out by The pH control system 20 is a batch operation because the discharge from the distillery is a batch operation. For example, approximately every two hours, two or three of the stills may be unloaded from either the first or the second distillation. In addition, the wash water is discharged whenever the collector of the washing water transfer pumps is full and the sanitary sewer discharge occurs throughout the day but the volume may vary during the day. Accumulating the material in the equalization tank and feeding the percolation filter continuously the size of the equipment used can be minimized due to the constant hydraulic flow. Moreover, by mixing the different currents, a concentration of biological oxygen demand and fairly uniform chemical oxygen demand can be obtained. This can allow an environment without change for the biomass and can help avoid problems due to sludge or high concentration of wastewater. The waste water is cooled along the flow path before entering the equalization tank 30. & * - Specifically, the temperature of the incoming wastewater can be as high as 70 to 80 ° C. The maximum temperature that the bioactive mass can tolerate before starting to die is approximately 40 ° C. Therefore, it is convenient to maintain the filter feeding temperature of percolation below 40 ° C. Preferably, the water is cooled to 35 ° C before entering the equalization tank 30 but may be allowed to remain at a higher temperature.

No high depending on the process. From the equalization tank 30, the residual water via valve 40 can be provided to a static mixer 42 and then to a primary clarifier 44. Static mixer 42 is used to ensure proper mixing of all chemical additives and to prevent them from settling in the process piping. On the outlet valve , there can be a flow transmitter 46, a recorder 48 and a thermometer 50. The primary clarifier 44 helps remove oil and grease, settleable solids and solids not removed by the centrifuge and final filter 6, or the solids (for example, phosphorous sludge) generated by the addition of slime in the equalization tank 30. The clarifier vessel 44 will also include a flocculation zone. The area of the flocculation vessel will include a chemical feed system to add ferric chloride (FeCl3) or hydrogen peroxide (H2O) to assist in the removal of phosphorus. The sludge from the primary clarifier 44 is transferred to sludge digester 54. in line 55 via one or more pumps 56, 58 and valves 60, 62, 64, 66, 68 and 70 for further processing. Air can be provided from the fan 57 to the bottom of the sludge digester 54 via the valve 59 in order to comminute the solids in the sludge digester 54. The sludge digester 54 allows continuous reduction of the solids. The solids can be composted to be used as fertilizer or discarded directly on the ground after stabilization with the slime. The residual water in the primary clarifier 44 is provided to a percolation filter 72 via one or more pumps 74, 76 and valves 78, 80, 82, 84, 86, 88, and 90. Afterwards, a valve may be used. check to avoid backward flow of the primary clarifier 44. At the outlet of the valve 90, there may be a flow transmitter 94 and a thermometer 96. The percolation filter 72 is used for the initial reduction of biological demand of oxygen, chemical oxygen demand, total suspended solids, nitrogen, phosphorus, oil and fat. The percolation filter 72 preferably comprises a contact plastic medium of high surface area, of high strength, and of light weight without the need for support structures or lower drainage. The percolation filter 72 may vary depending on the volume and strength of the waste to be treated. The trickling filter 72 can for example be 27.43 meters in diameter and 6.09 meters in depth and could be made of concrete, steel or plastic construction. In addition, the trickling filter 72 also includes a rotary distributor ^ 98 designed to evenly distribute the flow through the entire filter bed. The rotary distributor 98 is typically driven by hydraulic flow on self-supporting means 100. A fan 102 can be disposed at the bottom of the percolation filter in order to provide oxygen for the biomass for growth and respiration. A motorized distribution system can be used. However, a motorized distribution system is not needed where the process flow is large enough to drive the rotary distributor without further assistance. The trickling filter 72 uses a high recirculation ratio. Preferably, the recirculation ratio of the percolation filter 72 is between four to one and ten to one. The wastewater in the percolation filter 72 is supplied to an activated sludge unit 107. The activated sludge unit 107 comprises dual aeration basins 104 and a secondary clarifier 130. Specifically, the waste water from the percolation filter 72 is supplied to the dual aeration basins 104 in the line 105 via one or more pumps 106, 108 and valves 110, 112, 114, 116, 118, 120 and 122. The waste water of the Percolation filter 72 can also be recycled back into the percolation filter via line 124. Valve 122 controls the flow of waste water to the rest of the plant or to recirculate waste water to percolation filter 72. Aeration ponds 104 use biomass to remove the biological oxygen demand / chemical demand of residual oxygen in the percolation filter effluent and also reduce the incoming biomass of the percolation filter effluent. Specifically, the aeration tank 104 will reduce the biological oxygen demand, the chemical oxygen demand, and the solids in the waste water transported from the percolation filter 72. The concentration of the tank biomass preferably remains constant at about 3500 milligrams / liter. This results in a low proportion of food with respect to microorganisms. In this state, the bacteria do not have enough food to maintain all their growth and breathing requirements. Then they feed other bacteria in the pond. Excess bacteria from the percolation filters will be used in this way. This is the reason why the system has a very low global sludge production index (excess biomass). In addition, a valve 126 allows the fan 128 to provide air to the oscillating aerators located in the aeration tank 72 which, in turn, oxygenate the waste water thereby creating an additional demand removal. Residual water from the dual aeration ponds 104 is supplied to a secondary clarifier or final settling pond 130 The secondary clarifier or final settlement basin 130 recovers the biomass of the dual aeration basins 104 for recirculation and the recovered excess sludge is transferred to the sludge digester or thickener 54 for an 'additional treatment. The biomass in the aeration pond will flow into the secondary clarifier continuously. The biomass (ie, the mud) will stop from the water and recirculate to the aeration pond to maintain the proper concentration. The excess biomass can be transferred to the sludge digester 54 for waste. In addition, wastewater is provided from the effluent of the secondary clarifier 130 by means of a sand filter 134 via one or more pumps 136, 138 and valves 140, 142, 144, 146, 150, and 152. In addition, it can be arranged a flow transmitter 154 at the outlet of the valves 144, 146. Hydrogen peroxide 156 is added to the stream before the sand filter 134 in order to help remove the color of the waste water and oxidize any remaining chemical oxygen demand so that the level of chemical oxygen demand is lowered to the desired limits of the effluent. The sand filter 134 provides an additional reduction of the total suspended solids before the flow inlet to the carbon filters 158, 160. The waste water from the sand filter 134 can be supplied to one or more carbon filters 158, 160 via valves 162, 164. The * Carbon filters 158, 160 remove the biological oxygen demand, the chemical oxygen demand, the soluble nitrogen and the remaining color of the effluent. Washing with clean countercurrent water from the charcoal filters 158, 160 is supplied to a water storage tank of the backwashing effluent 166 via the valve 174. The waste water from the charcoal filters 158, 160 is supplied to a disinfection tank 176 via valves 178, 180. Chlorine (Cl2) 182 is added to the tank.

* Disinfection 176 in order to help disinfect wastewater. The waste water can then be supplied to a water storage tank of effluent 184 for disposal via valve 188. The effluent from plant 186 can, for example, flow from the water storage tank of effluent 184 to a rate of 6.615 liters per second. Countercurrent rinsing water is provided from the water storage tank of effluent 184 to sand filter 134 and carbon filters 158, 160 via one or more pumps 190, 192 and valves 194, 196, 198, 200, 202, 204, 206, 208, 210 and 212 for further processing in a closed cycle system. Then, a flow transmitter 214 can be provided at the outputs of the valves 204, 206. As for the water storage tank of the countercurrent rinsing effluent 166, the contained sludge c * therein can be discharged at 216 to waste via one or more pumps 218, 220 and valves 222, 224, 226, 228, 230, 232 and 234. In addition, the sludge digester sludge 54 can also be discharged to the waste outlet 216 via valves 236, 224, 226, 228, 230, 232 and 234 and the pumps 218, 220. The countercurrent rinsing water can be recycled to the aeration tank for treatment after it is used in the countercurrent rinsing of the filter. Sludge digester sludge 54 can also be recycled to dual aeration ponds 104 due to the closed cycle system and to minimize the removal or waste of sludge. One or more pumps 238, 240 and valves 242, 244, 246, 248, 250, 252, and 254 can be used to provide the sludge from the sludge digester 54 to the aeration tank 104. It should be recognized that, although the present invention has been described with respect to preferred embodiments thereof, those skilled in the art can develop a wide variety of structural details without departing from the principles of the invention. Therefore, the appended claims should be considered to cover all equivalents that fall within the true scope and spirit of the invention.

Claims (17)

1. CLAIMS 1. A wastewater treatment system comprising a percolation filter, an activated sludge unit disposed downstream of the percolation filter, and at least one filter disposed downstream of the activated sludge unit; r "wherein the percolation filter recycles the wastewater in a ratio of four to one or greater 2. The invention of claim 1, wherein the percolation filter recycles waste water in a ratio of four to one to ten 3. The invention of claim 1, wherein hydrogen peroxide is added to treat the waste water 4. The invention of claim 1, wherein r * The system is used for the treatment of wastewater produced during the manufacture of alcohol. 5. The invention of claim 4, wherein the alcohol is tequila. The invention of claim 5 wherein the activated sludge unit comprises dual aeration ponds and a clarifier and at least one filter comprises 25 sand and carbon filters. 7. A system for treating wastewater produced during the production of tequila comprising a filter a pH control system arranged downstream of the filter; an equalization tank arranged downstream of the pH control system; a primary clarifier disposed downstream of the equalization tank; a percolation filter disposed downstream of the percolation filter, and a plurality of filters disposed downstream of the activated sludge unit. The invention of claim 7, wherein the percolation filter recycles waste water in a ratio of four to one or greater. The invention of claim 8, wherein the percolation filter recycles waste water in a ratio of four to one and ten to one. The invention of claim 9, wherein hydrogen peroxide is added to treat the waste water before the sand filter. The invention of claim 10, wherein the activated sludge unit comprises dual aeration ponds and a clarifier and a plurality of filters comprises sand and carbon filters. * 12. The invention of claim 11, wherein hydrogen peroxide is added to treat the waste water before the sand filter. 13. A method for treating wastewater resulting from the production of alcohol comprising: providing waste water to a filter; adjust the pH of the wastewater; provide the wastewater to an iF tank "equalization; provide the wastewater to a primary clarifier; provide the wastewater to a percolation filter, recycling the percolation filter to the residual water in a ratio of between four to one and ten to one, to provide hydrogen peroxide to the waste water, and to provide the waste water to sand and carbon filters. The method of claim 13 wherein a caustic, calcium hydroxide, or magnesium hydroxide is provided to the waste water. before the step of adjusting the pH of the wastewater 15. The method of claim 13 which further comprises the steps of adding ferric chloride or hydrogen peroxide to the primary clarifier. * 16. The method of claim 13, wherein the sludge from the secondary clarifier is provided to a sludge digester 17. The method of claim 13, wherein the sludge from the primary clarifier is provided to a digester. of mud and S The method of claim 13, wherein the alcohol is tequila.