Title of Invention	A PROCESS FOR ELIMINATION OF COLOR, ODOR AND REDUCTION OF BIOLOGICAL OXYGEN DEMAND (BOD) AND CHEMICAL OXYGEN DEMAND (COD) OF DISTILLERY EFFLUENTS
Abstract	The present invention relates to a process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent, said process comprising the steps of; adding to the distillery effluent one or more alkali metal salts and/or one or more alkaline earth metal salts with alkali hydroxide to from a precipitate, separating the precipitate thus formed and optionally, repeating the above process one or more time till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow. To the supernatant, alum and alkali is added to form a precipitate entrapping remaining inorganic / organic impurities and thereby formed a substantially colorless, odorless effluent subjected to filtration using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD.

Title of Invention

A PROCESS FOR ELIMINATION OF COLOR, ODOR AND REDUCTION OF BIOLOGICAL OXYGEN DEMAND (BOD) AND CHEMICAL OXYGEN DEMAND (COD) OF DISTILLERY EFFLUENTS

Abstract

The present invention relates to a process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent, said process comprising the steps of; adding to the distillery effluent one or more alkali metal salts and/or one or more alkaline earth metal salts with alkali hydroxide to from a precipitate, separating the precipitate thus formed and optionally, repeating the above process one or more time till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow. To the supernatant, alum and alkali is added to form a precipitate entrapping remaining inorganic / organic impurities and thereby formed a substantially colorless, odorless effluent subjected to filtration using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD.

Full Text	A PROCESS FOR ELIMINATION OF COLOR, ODOR, AND REDUCTION OF BIOLOGICAL OXYGEN DEMAND (BOD) AND CHEMICAL OXYGEN DEMAND (COD) OF DISTILLERY EFFLUENTS. FIELD OF THE INVENTION The present invention relates to a process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent using a system of continuous treatment process. More Particularly, the process involves absorption of the color and precipitation of the organic matter by mixing appropriate chemicals at optimum pH and temperature and filtering of the adsorbed material by using bio degradable /combustible materials like paddy husk or saw dust which can be dried and used as a manure or can be used as a fuel to boiler(s) for generating energy/steam or can be incinerated completely to reduced the impurities to innocuous ash. BACKGROUND OF THE INVENTION The approaches made so far to treat the industrial affluence particularly of distilleries have been operating in two stages. Normally (1) aeration process where the effluent is either agitated or exposed to heavy air bubbling / purging using compressors (2) the second stage involves the anaerobic breakdown of bacteria by storing the effluents in large pits over a period of several days/weeks. In recent years the third approach is being widely practiced which is referred to as methanogenesis to recover CH3 to be subsequently used as fuel. The points for serious consideration are on one hand all the above process are very tedious and time consuming. In spite of this the BOD and COD of the treated effluents in many industries have not been able to comply with pollution board standards. Even in the industries other than distilleries the manufacturers have designed several processing schedules to bring the effluents close to the pollution control standards. In a survey undertaken by the Applicants revealed that many of the schedules are not only expensive but also time consuming. In these days of growing short supply of basic raw materials, it is becoming inevitable to concentrate on the recovery of at least a few basic chemicals used in the process. Although the industrial expansion is vital to the progress of the country but few major problems associated with this expansion are threatening the welfare of mankind negating the expected comfort and happiness bestowed by industrial sector. In the first place the industry generates voluminous quantities of the waste liquids, which are not only detrimental to a healthy environment but also hazardous to biological life of the soil and water. The third problem centers on the interference with the availability of potable water for human consumption. Viewing at the huge quantities of water consumed by these industries, continuous availability of ground water is seriously affected leading to great water crisis in future years. These threatening problems demand an appropriate solution in finding out methods to reduce the pollution potential of these effluents and also to make sure that the natural water cycle is not interrupted in any way by designing processes for recycling. At the moment the major pollutants is from the distilleries and several measure have been practiced to minimize their health hazard. The limitations of these processes under practice are the high-energy intensive methods, vast land area and use of chemicals. Meenambal has reviewed in her article on discoloration of the treated distillery effluents and reports that the size of the output of the effluent from the distilleries is of order of the 130 billion liters of waste water with a very high BOD and COD with strong objectionable color and odor. The author has also summarized various methods to minimize the problem of color, odor, high COD and BOD of the effluent. Earlier studies to find an appropriate solution to this problem have concentrated on two major aspects. 1) By chemical means 2) By biological agents. The chemical method involves the use of coagulants to remove the organic contaminants and the biological method involves aerobic as well as anaerobic oxidation by suitable microbial activity.The coagulants tried (Ramachandra) for this purpose include Alum, Ferric chloride, Polyelectrolytes and calcium salts. Although the author claimed 80 to 90% removal of color and reduction of COD and BOD, the volume of chemicals used is of order of 20 to 50gms/ltr. This is a very high level to stand the test of economics as well as the speed of operations. Further all the earlier works attempting coagulation process have not suggested any practically feasible methods of separating the coagulum. What ever be the efficiency claimed in the article, this is a serious limitation for practical application of the methods worked out. Ramachandra point out at this stage that pollution board expects that all efforts should be made to remove color and unpleasant odor as practical as possible. This means even the pollution control board has realized that there is no set method for totally removing the color and odor. In view of the above limitation there is an urgent need to develop a process, which does not involve use of vast area, and long time duration for achieving the minimum standard. With reference to the alcohol distillery industries, the color of the effluent is indistructable. There have been complaints in all surrounding areas of these industries about this problem. Even the ground water is being contaminated with the color. In this context it is pertinent to point out the cancellation of licenses to some of these industries by the pollution board. This highlights the urgency of a process that can answer all these above limitations. The process under reference in this application has met all the above limitations and the Applicant is able to obtain odorless, colorless water with very low dissolved solids, which is fit for recycling in the industry, meeting the pollution specifications. In all the processes so far followed to meet the pollution control board limits, the treatment process requires 1-4 weeks of holding time. OBJECTIVES OF THE INVENTION The prime objective of the present invention is to provide a process for the removal of color, odor, reduction of COD and BOD of a distillery effluent to overcome the above-mentioned drawbacks and to meet out the standards conventionally specified by pollution control board. Another objective of the present invention is to provide a process which helps in reducing the treatment time period to a few hours as compared to several weeks or months, further reducing considerably the land area being required for treatment of the effluents in the processes and drastically cutting down electrical energy normally consumed in the existing processes. Yet another objective of the present invention is to recycle part of water required for the whole process and to conserve water resources so that level of underground water is recharged and provide a feasible solution for preventing the environmental pollution by factory wastes. Still another objective of the present invention is to use biodegradable / combustible material as filtering material as filters such as paddy husk or saw dust so that it can be use as manure or burnt to generate heat energy SUMMARY OF THE INVENTION The present invention relates to a process under reference helps in totally removing the problem of color and odor of the effluent. The present process also helps in reducing the time required as well as the amount of electrical energy normally required to treat the effluents. Since the pollution standards fixed to ensure safety of the environment are very strict, the present process consumes less time, less space and less electrical power. More particularly, the present process is a continuous process and takes hardly 1-5 hrs. The cost of the treatment works out to be approximately 2.0 paise/ltr. Chemical Reactions involved in the present process are mainly Reaction -1 Caclz + 2 NaOH--> 2 NaCl + Ca (OH) 2 This is primary reaction that is operative in the whole process. In the first step, interaction between NaOH and CaCb, take places and a major portion of the coloring and odorous organic matter gets adsorbed on the precipitated matter. At the optimum PH of 10.0 during the formation of calcium hydroxide precipitation the organic color gets entrapped. Thus this reaction helps in removing the color and odor to a maximum extent. The organic pollutants are to be adsorbed and settle down between Calcium chloride and Sodium hydroxide. It is observed that with the reduction of the major portion of the organic matter in the first step, and if further small portion of the organic matter remains in the effluent, which include color and odorous materials. This requires repetition of primary step one or more times till the solution consist total solid contain in the effluent less than 8 to 9 % and the color of the supernatant is in light yellow color. In the normal course a 2nd treatment with CaCl2 and NaOH will be sufficient to remove nearly 95 to 98% of the organic matter. If the total solids of the effluent is higher than 8 to 9% a third repetition of primary step is required with CaCl2 and NaOH before to the final treatment. Reaction-2 Alum + NaOH -> precipitate In the next step wherein only alum and NaOH, at very low levels are used for total removal of color and odorous impurities from the remaining effluent. While Alum react with alkali and gets partially hydrolyzed. One or more of the hydrolyzed products may be responsible for the observed action of Alum. Adsorption in general is the process of collecting soluble substances that are in solution on a suitable interface. The interface can be between the liquid and a gas, a solid or another liquid. Although adsorption is used at the air liquid interface in the flotation process, only the case of adsorption at liquid solid interface will be important. In the present invention it is the interface between the liquid and the solid precipitate of alum that is operative in removing the color. The last step with alum is only a fine tuning step, where in last traces of color are expected to be removed. If the total solid content of the effluent is higher than 8%, then it has to be diluted to reduce the solids up to 4-5% (half of the original concentration} for the chemical reaction. This can be achieved by either directly adding water (recycling treated water) or by using more diluted solutions of the reagents keeping the final concentrations of the reagents at the required level. The degree of the dilution i.e volume of the reactants added to the effluent will be in the range of 1:5. STATEMENT OF THE INVENTION The present invention relates to a eco-friendly process for removal of color, odor and reducing in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluents said process comprising the steps of: a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or more times till the effluent contains less than 8 to 9 % of total solid content and color of the supernatant is light yellow; b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic/organic impurities and thereby formed a substantially colorless odorless effluent; and c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD. LIST OF TABLES: Table 1 compares parameters of distillery digester effluent with treated distillery effluent. Table 2 showing optical density and percentage solid separated of treated distillery effluent Table 3 depicts effect of degree of dilution on the characteristics of the filtration process and filtrate. Table 4 showing stepwise reduction of color and odor of the effluent following in the treatment DETAILED DESCRIPTION OF THE INVENTION Accordingly, the present invention relates to a eco-friendly process for removal of color, odor and reduction in Biological oxygen demand (BOD) and chemical oxygen demand (COD) of a distillery effluents said process comprising the steps of; a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or more times till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow; b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic/organic impurities and thereby formed a substantially colorless, odorless effluent; and c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD. In an embodiment of the present invention, metals of alkali metal salts are selected from Li,Na, K, Rb, Cs and Fr. In another embodiment of the present invention, metals of alkaline earth metal salts are selected from Be, Mg, Ca, Sr, Ba and Ra. In one another embodiment of the present invention, in step (a), the precipitate thus formed contains inorganic / organic color impurities. In yet another embodiment of the present invention, the precipitate thus formed contains organic color impurities. In yet another embodiment of the present invention, the distillery effluent has BOD value in the range of 3500 to 7000 mg/L. In yet another embodiment of the present invention, the distillery effluent has BOD value of about 5000 to 6000 mg/L. In yet another embodiment of the present invention, the distillery effluent has COD value in the range of 11000 to 17000 mg/L. In yet another embodiment of the present invention, the distillery effluent has COD value 14000 to 14500 mg/L. In yet another embodiment of the present invention, in step (a), salt of calcium is used with sodium hydroxide. Still another embodiment of the present invention, in step (a), pH value is in the range of 6 to 10.0. In yet another embodiment of the present invention, in step (a), about 7.5 % calcium salt and of about 5 % NaOH is used. In still another embodiment of the present invention, in step (b), about 5,0 % alum and 0.5 % alkali is used. In yet another embodiment of the present invention, in step (c), substantially colorless, odorless treated effluent has an optical density of 100%. Still another embodiment of the present invention in step (c), substantially colorless, odorless, treated effluent obtained has BOD value 100 to 120 times lower and COD values 65 to 85 times lower from the respective initial values of distillery effluent. In yet another embodiment of the present invention, in step (c) the filtering media is selected from the group comprising coarse filter paper, Bagas or Paddy husk. In still further embodiment of the present invention, wherein the time period for treating the distillery effluent is in the range of 1 hour 10 minute to 6 hours. In yet another embodiment the time period for treating the distillery effluent in step (a), is in the range of 1 hour to 4 hours. In yet another embodiment of the present invention, the time period for treating the distillery effluent in last step, is in the range of 10 minute to 3 hours. In yet another embodiment of the present invention, step (a) is repeated two times, if the solid content in the distillery effluent exist more than 65 to 85 %. In one more embodiment of the present invention, the step (a) is repeated three times, if the solid content in the distillery effluent exist more than 8 to 9 %. If the total solid content of the effluent is higher than 8 to 9 %, then it has to be diluted to reduce the solids up to 4-5% (half of the original concentration} for the chemical reaction. which can be achieved by either directly adding water (recycling treated water) or by using more diluted solutions of the reagents keeping the final concentrations of the reagents at the required level. The degree of the dilution i.e volume of the reactants added to the effluent will be in the range of 1:5. The table 3 depicts the effect of degree of dilution on the characteristics of the filtration process and filtrate. These observations suggested that dilution of the effluent bring down the TDS content lower up to 3-4 % solids before the addition of CaCh is usefiil in this treatment process. In this context the present invention has covered the effluents of a few industries and worked out process for recovery of some raw materials. The process for treating the distillery effluent involves conversion of the pigment and other organic chemicals to an insoluble complex, which can be easily filtered and incinerated to destroy totally the polluting chemicals of the effluent. To achieve this several compounds such as aluminum saUs, calcium salts and sodium salts, acids as well as alkalis have been systematically examined. While in most of the cases a partial reduction of the color, odor, COD and BOD was achieved. The time taken for the treatment process depends upon the load of the pollutant. Further the whole process could be completed in few hours time. Since it is purification followed by filtration, the process can be deemed as a continuous operation not involving storage for long periods at any stage. The process comprises of serial filtration equipment made up of tin material boats measuring 3-4 feet diameter 8" and depth 6". The boat carries an inner ridge at several points on the inner sides of the boat to hold perforated sheets covered with a coarse cloth. Raw or burnt paddy husk is spread on this cloth. This arrangement serves as the filtering media. The filtrate collected in the bottom is drained out to a reservoir. This leads on to another boat having the same arrangement. Similarly two such arrangements are used in the whole process in sequential order. The vital portion of the invention lies in the selection of appropriate chemical and an ideal reaction environment for forming the complex. In the early stages the following schedule was examined. The distillery effluent mixed with limewater or sodium alluminate or sodium sulphate at a pH ranging fi"om 6 to 10. After each mixing, the mixture is filtered through filtering media such as coarse filter paper, Bagas or paddy husk. The calorific value of Bagas 2200 K.Cals/Kg (wet) and 4400 K.Cals/kg (Dry) and Paddy Husk are -3300 K.Cals/Kg Applicant determined the filtrate color, BOD and COD and found to be unsuitable for discharge at this stage. As most of the unwanted materials, in the filtrate are found to be colloidal suspensions, centrifixgation or activated carbon, which are attempted for treatment. However, the carbon treatment helped to remove the color and reduce the COD or BOD to a considerable extent to the cost of the treatment. More particularly, activated carbon became prohibitive for application. This suggested that a more economical and effective approach should be examined. During the course of work Applicants noticed that absorption of the color on the precipitate formed during the chemical reaction between the effluent constituents and chemicals used was most striking. This provided a clue for the total removal of color by facilitating maximum and bigger precipitated particle would be a feasible solution for the same. In this context formation of an insoluble salt of calcium in conjunction with colored materials of the effluents was found to be most helpful in solving the problem of color. A soluble salt of calcium mixed with the effluents at various PH was found to be most appropriate solution. This is the crux of the whole invention. Another salient feature of this process is the utilization of paddy husk to filter off the insoluble matter. The husk so used can either be incinerated or fed into a boiler; thus completely destroying of color and associated organic impurity. ADVANTAGES OF THE PRESENT INVENTION I) Duration of the treatment is reduced from months to few hours. II) Considerable reduction in electrical energy expenditure. III) The whole operation can be designed as a continuous process. IV) The reduction in BOD has been achieved from 5000 to 60 in the case of effluent discharge after methanogenesis. In the direct discharge from the distillery with an initial BOD i.e., 30 to 50,000 the reduction achieved is of about 386mgl/lt. V) Foul odors around the distillery are totally eliminated. VI) Since the color is totally removed there is no color seepage to ground water. VII) The chemicals used are absolutely non toxic and easily available. Filtering medium is also commonly available. Course materials such as paddy husk, which can be later, burnt by feeding to the boiler thus reducing the organic insoluble complex to CO2 and H2O. VIII) Most important advantage of the process is minimal amount of ground or surface water tapped throughout the day. Table-1 compares parameters of distillery digester effluent with treated distillery effluent. Table-2: Showing optical density and percentage solid separated of distillery effluent on treatment. WE CLAIM 1 An eco-friendly process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent, said process comprising the steps of; a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or more times till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow; b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic / organic impurities and thereby formed a substantially colorless, odorless effluent; and c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD. 2 A process as claimed in claim 1, wherein the metals of alkali metal salt are selected from Li, Na, K, Rb, Cs and Fr. 3 A process as claimed in claim 1, wherein the metals of alkaline earth metal salts are selected from the Be, Mg, Ca, Sr, Ba and Ra. 4 A process as claimed in claim 1 wherein in step (a), the precipitate thus formed contains inorganic / organic color impurities. 5 A process as claimed in claim 4, wherein the precipitate thus formed contains organic color impurities. - 6 A process as claimed in claim 1, wherein the distillery effluent has BOD value in the range of 3500 to 7000 mg/L. 7 A process as claimed in claim 6, wherein the distillery effluent has BOD value in the range of 5000 mg/L to 6000 mg/L. 8 A process as claimed in claim 1, wherein the distillery effluent has COD value in the range of 11000 to 17000 mg/L. 9 A process as claimed in claim 8, wherein the distillery effluent has COD value in the range of 14000 to 14500 mg/L. 10 A process as claimed in claim 1, wherein in step (a), sal of calcium is used with sodium hydroxide. 11 A process as claimed in claim 1, wherein in step (a), pH value is in the range of 6 to 10.0. 12 A process as claimed in claim 1 wherein in step (a), about 7.5 % calcium salt and of about 5 % NaOH is used. 13 A process as claimed in claim 1 wherein in step (b), about 5 % alum and of about 0.5% alkali is used. 14 A process as claimed in claim 1 wherein in step (c), substantially colorless, odorless treated effluent has an optical density of 100 %. 15 A process as claimed in claim 1 wherein in step (c), substantially colorless, odorless treated effluent obtained has BOD value 100 to 120 times lower and COD values 65 to 85 times lower from the respective initial values of distillery effluent. 16 A process as claimed in claim 1 wherein in step (c), filtering media is selected from the group comprising coarse filter paper, Bagas or paddy husk. 17 A process as claimed in claim 1, wherein time period .for treating the distillery effluent is in the range of 1 hour 10 minute to 6 hours. 18 A process as claimed in claim 1, wherein time period for treating the distillery effluent in step (a) is in the range of 1 hour to 4 hours. 19 A process as claimed in claim 1, wherein time period for treating the distillery effluent in last step is in the range of 10 minute to 3 hours. 20 A process as claimed in claim 1, wherein the step (a) is repeated two times, if the solid content in the distillery effluent exist more than 65 to 85 %. 21 A process as claimed in claim 1, wherein the step (a) is repeated three times, if the solid content in the distillery effluent exist more than 8 to 9 %. 22 An eco-friendly process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent substantially as herein described and illustrated therein.

Full Text

A PROCESS FOR ELIMINATION OF COLOR, ODOR, AND REDUCTION OF BIOLOGICAL OXYGEN DEMAND (BOD) AND CHEMICAL OXYGEN DEMAND (COD) OF DISTILLERY EFFLUENTS.
FIELD OF THE INVENTION
The present invention relates to a process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent using a system of continuous treatment process. More Particularly, the process involves absorption of the color and precipitation of the organic matter by mixing appropriate chemicals at optimum pH and temperature and filtering of the adsorbed material by using bio degradable /combustible materials like paddy husk or saw dust which can be dried and used as a manure or can be used as a fuel to boiler(s) for generating energy/steam or can be incinerated completely to reduced the impurities to innocuous ash.
BACKGROUND OF THE INVENTION
The approaches made so far to treat the industrial affluence particularly of distilleries have been operating in two stages. Normally (1) aeration process where the effluent is either agitated or exposed to heavy air bubbling / purging using compressors (2) the second stage involves the anaerobic breakdown of bacteria by storing the effluents in large pits over a period of several days/weeks. In recent years the third approach is being widely practiced which is referred to as methanogenesis to recover CH3 to be subsequently used as fuel. The points for serious consideration are on one hand all the above process are very tedious and time consuming. In spite of this the BOD and COD of the treated effluents in many industries have not been able to comply with pollution board standards. Even in the industries other than distilleries the manufacturers have designed several processing schedules to bring the effluents close to the pollution control standards. In a survey undertaken by the Applicants revealed that many of the schedules are not only expensive but also time consuming. In these days of growing short supply of basic raw materials, it is becoming inevitable to concentrate on the recovery of at least a few basic chemicals used in the process.

Although the industrial expansion is vital to the progress of the country but few major problems associated with this expansion are threatening the welfare of mankind negating the expected comfort and happiness bestowed by industrial sector. In the first place the industry generates voluminous quantities of the waste liquids, which are not only detrimental to a healthy environment but also hazardous to biological life of the soil and water. The third problem centers on the interference with the availability of potable water for human consumption.
Viewing at the huge quantities of water consumed by these industries, continuous availability of ground water is seriously affected leading to great water crisis in future years. These threatening problems demand an appropriate solution in finding out methods to reduce the pollution potential of these effluents and also to make sure that the natural water cycle is not interrupted in any way by designing processes for recycling. At the moment the major pollutants is from the distilleries and several measure have been practiced to minimize their health hazard. The limitations of these processes under practice are the high-energy intensive methods, vast land area and use of chemicals. Meenambal has reviewed in her article on discoloration of the treated distillery effluents and reports that the size of the output of the effluent from the distilleries is of order of the 130 billion liters of waste water with a very high BOD and COD with strong objectionable color and odor. The author has also summarized various methods to minimize the problem of color, odor, high COD and BOD of the effluent. Earlier studies to find an appropriate solution to this problem have concentrated on two major aspects. 1) By chemical means 2) By biological agents.
The chemical method involves the use of coagulants to remove the organic contaminants and the biological method involves aerobic as well as anaerobic oxidation by suitable microbial activity.The coagulants tried (Ramachandra) for this purpose include Alum, Ferric chloride, Polyelectrolytes and calcium salts. Although the author claimed 80 to 90% removal of color and reduction of COD and BOD, the volume of chemicals used is of order of 20 to 50gms/ltr. This is a very high level to stand the test of economics as well as

the speed of operations. Further all the earlier works attempting coagulation process have not suggested any practically feasible methods of separating the coagulum. What ever be the efficiency claimed in the article, this is a serious limitation for practical application of the methods worked out. Ramachandra point out at this stage that pollution board expects that all efforts should be made to remove color and unpleasant odor as practical as possible. This means even the pollution control board has realized that there is no set method for totally removing the color and odor.
In view of the above limitation there is an urgent need to develop a process, which does not involve use of vast area, and long time duration for achieving the minimum standard. With reference to the alcohol distillery industries, the color of the effluent is indistructable. There have been complaints in all surrounding areas of these industries about this problem. Even the ground water is being contaminated with the color. In this context it is pertinent to point out the cancellation of licenses to some of these industries by the pollution board. This highlights the urgency of a process that can answer all these above limitations. The process under reference in this application has met all the above limitations and the Applicant is able to obtain odorless, colorless water with very low dissolved solids, which is fit for recycling in the industry, meeting the pollution specifications. In all the processes so far followed to meet the pollution control board limits, the treatment process requires 1-4 weeks of holding time.
OBJECTIVES OF THE INVENTION
The prime objective of the present invention is to provide a process for the removal of color, odor, reduction of COD and BOD of a distillery effluent to overcome the above-mentioned drawbacks and to meet out the standards conventionally specified by pollution control board.
Another objective of the present invention is to provide a process which helps in reducing the treatment time period to a few hours as compared to several weeks or months, further reducing considerably the land area being required for treatment of the effluents in the processes and drastically cutting down electrical energy normally consumed in the existing processes.

Yet another objective of the present invention is to recycle part of water required for the whole process and to conserve water resources so that level of underground water is recharged and provide a feasible solution for preventing the environmental pollution by factory wastes.
Still another objective of the present invention is to use biodegradable / combustible material as filtering material as filters such as paddy husk or saw dust so that it can be use as manure or burnt to generate heat energy
SUMMARY OF THE INVENTION
The present invention relates to a process under reference helps in totally removing the problem of color and odor of the effluent. The present process also helps in reducing the time required as well as the amount of electrical energy normally required to treat the effluents. Since the pollution standards fixed to ensure safety of the environment are very strict, the present process consumes less time, less space and less electrical power. More particularly, the present process is a continuous process and takes hardly 1-5 hrs. The cost of the treatment works out to be approximately 2.0 paise/ltr.
Chemical Reactions involved in the present process are mainly Reaction -1 Caclz + 2 NaOH--> 2 NaCl + Ca (OH) 2
This is primary reaction that is operative in the whole process. In the first step, interaction between NaOH and CaCb, take places and a major portion of the coloring and odorous organic matter gets adsorbed on the precipitated matter. At the optimum PH of 10.0 during the formation of calcium hydroxide precipitation the organic color gets entrapped. Thus this reaction helps in removing the color and odor to a maximum extent. The organic pollutants are to be adsorbed and settle down between Calcium chloride and Sodium hydroxide. It is observed that with the reduction of the major portion of the organic matter in the first step, and if further small portion of the organic matter remains in the effluent, which include color and odorous materials. This requires repetition of primary step one or

more times till the solution consist total solid contain in the effluent less than 8 to 9 % and the color of the supernatant is in light yellow color. In the normal course a 2nd treatment with CaCl2 and NaOH will be sufficient to remove nearly 95 to 98% of the organic matter. If the total solids of the effluent is higher than 8 to 9% a third repetition of primary step is required with CaCl2 and NaOH before to the final treatment.
Reaction-2 Alum + NaOH -> precipitate
In the next step wherein only alum and NaOH, at very low levels are used for total removal of color and odorous impurities from the remaining effluent.
While Alum react with alkali and gets partially hydrolyzed. One or more of the hydrolyzed products may be responsible for the observed action of Alum. Adsorption in general is the process of collecting soluble substances that are in solution on a suitable interface. The interface can be between the liquid and a gas, a solid or another liquid. Although adsorption is used at the air liquid interface in the flotation process, only the case of adsorption at liquid solid interface will be important. In the present invention it is the interface between the liquid and the solid precipitate of alum that is operative in removing the color. The last step with alum is only a fine tuning step, where in last traces of color are expected to be removed.
If the total solid content of the effluent is higher than 8%, then it has to be diluted to reduce the solids up to 4-5% (half of the original concentration} for the chemical reaction. This can be achieved by either directly adding water (recycling treated water) or by using more diluted solutions of the reagents keeping the final concentrations of the reagents at the required level.
The degree of the dilution i.e volume of the reactants added to the effluent will be in the range of 1:5.
STATEMENT OF THE INVENTION
The present invention relates to a eco-friendly process for removal of color, odor and reducing in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluents said process comprising the steps of:

a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or more times till the effluent contains less than 8 to 9 % of total solid content and color of the supernatant is light yellow;
b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic/organic impurities and thereby formed a substantially colorless odorless effluent; and
c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD.
LIST OF TABLES:
Table 1 compares parameters of distillery digester effluent with treated distillery effluent.
Table 2 showing optical density and percentage solid separated of treated distillery effluent
Table 3 depicts effect of degree of dilution on the characteristics of the filtration process
and filtrate.
Table 4 showing stepwise reduction of color and odor of the effluent following in the
treatment
DETAILED DESCRIPTION OF THE INVENTION
Accordingly, the present invention relates to a eco-friendly process for removal of color, odor and reduction in Biological oxygen demand (BOD) and chemical oxygen demand (COD) of a distillery effluents said process comprising the steps of;
a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or

more times till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow;
b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic/organic impurities and thereby formed a substantially colorless, odorless effluent; and
c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD.
In an embodiment of the present invention, metals of alkali metal salts are selected from
Li,Na, K, Rb, Cs and Fr.
In another embodiment of the present invention, metals of alkaline earth metal salts are
selected from Be, Mg, Ca, Sr, Ba and Ra.
In one another embodiment of the present invention, in step (a), the precipitate thus formed
contains inorganic / organic color impurities.
In yet another embodiment of the present invention, the precipitate thus formed contains
organic color impurities.
In yet another embodiment of the present invention, the distillery effluent has BOD value
in the range of 3500 to 7000 mg/L.
In yet another embodiment of the present invention, the distillery effluent has BOD value
of about 5000 to 6000 mg/L.
In yet another embodiment of the present invention, the distillery effluent has COD value
in the range of 11000 to 17000 mg/L.
In yet another embodiment of the present invention, the distillery effluent has COD value
14000 to 14500 mg/L.
In yet another embodiment of the present invention, in step (a), salt of calcium is used with
sodium hydroxide.
Still another embodiment of the present invention, in step (a), pH value is in the range of 6
to 10.0.
In yet another embodiment of the present invention, in step (a), about 7.5 % calcium salt
and of about 5 % NaOH is used.

In still another embodiment of the present invention, in step (b), about 5,0 % alum and 0.5
% alkali is used.
In yet another embodiment of the present invention, in step (c), substantially colorless,
odorless treated effluent has an optical density of 100%.
Still another embodiment of the present invention in step (c), substantially colorless,
odorless, treated effluent obtained has BOD value 100 to 120 times lower and COD values
65 to 85 times lower from the respective initial values of distillery effluent.
In yet another embodiment of the present invention, in step (c) the filtering media is
selected from the group comprising coarse filter paper, Bagas or Paddy husk.
In still further embodiment of the present invention, wherein the time period for treating
the distillery effluent is in the range of 1 hour 10 minute to 6 hours.
In yet another embodiment the time period for treating the distillery effluent in step (a), is
in the range of 1 hour to 4 hours.
In yet another embodiment of the present invention, the time period for treating the
distillery effluent in last step, is in the range of 10 minute to 3 hours.
In yet another embodiment of the present invention, step (a) is repeated two times, if the
solid content in the distillery effluent exist more than 65 to 85 %.
In one more embodiment of the present invention, the step (a) is repeated three times, if the
solid content in the distillery effluent exist more than 8 to 9 %.
If the total solid content of the effluent is higher than 8 to 9 %, then it has to be diluted to
reduce the solids up to 4-5% (half of the original concentration} for the chemical reaction.
which can be achieved by either directly adding water (recycling treated water) or by using
more diluted solutions of the reagents keeping the final concentrations of the reagents at
the required level. The degree of the dilution i.e volume of the reactants added to the
effluent will be in the range of 1:5. The table 3 depicts the effect of degree of dilution on
the characteristics of the filtration process and filtrate. These observations suggested that
dilution of the effluent bring down the TDS content lower up to 3-4 % solids before the
addition of CaCh is usefiil in this treatment process.
In this context the present invention has covered the effluents of a few industries and
worked out process for recovery of some raw materials. The process for treating the

distillery effluent involves conversion of the pigment and other organic chemicals to an insoluble complex, which can be easily filtered and incinerated to destroy totally the polluting chemicals of the effluent.
To achieve this several compounds such as aluminum saUs, calcium salts and sodium salts, acids as well as alkalis have been systematically examined. While in most of the cases a partial reduction of the color, odor, COD and BOD was achieved. The time taken for the treatment process depends upon the load of the pollutant. Further the whole process could be completed in few hours time. Since it is purification followed by filtration, the process can be deemed as a continuous operation not involving storage for long periods at any stage. The process comprises of serial filtration equipment made up of tin material boats measuring 3-4 feet diameter 8" and depth 6". The boat carries an inner ridge at several points on the inner sides of the boat to hold perforated sheets covered with a coarse cloth. Raw or burnt paddy husk is spread on this cloth. This arrangement serves as the filtering media. The filtrate collected in the bottom is drained out to a reservoir. This leads on to another boat having the same arrangement. Similarly two such arrangements are used in the whole process in sequential order.
The vital portion of the invention lies in the selection of appropriate chemical and an ideal reaction environment for forming the complex. In the early stages the following schedule was examined. The distillery effluent mixed with limewater or sodium alluminate or sodium sulphate at a pH ranging fi"om 6 to 10. After each mixing, the mixture is filtered through filtering media such as coarse filter paper, Bagas or paddy husk. The calorific value of Bagas 2200 K.Cals/Kg (wet) and 4400 K.Cals/kg (Dry) and Paddy Husk are -3300 K.Cals/Kg Applicant determined the filtrate color, BOD and COD and found to be unsuitable for discharge at this stage. As most of the unwanted materials, in the filtrate are found to be colloidal suspensions, centrifixgation or activated carbon, which are attempted for treatment. However, the carbon treatment helped to remove the color and reduce the COD or BOD to a considerable extent to the cost of the treatment. More particularly, activated carbon became prohibitive for application. This suggested that a more economical and effective approach should be examined. During the course of work Applicants noticed that absorption of the color on the precipitate formed during the

chemical reaction between the effluent constituents and chemicals used was most striking.
This provided a clue for the total removal of color by facilitating maximum and bigger
precipitated particle would be a feasible solution for the same.
In this context formation of an insoluble salt of calcium in conjunction with colored
materials of the effluents was found to be most helpful in solving the problem of color. A
soluble salt of calcium mixed with the effluents at various PH was found to be most
appropriate solution. This is the crux of the whole invention.
Another salient feature of this process is the utilization of paddy husk to filter off the
insoluble matter. The husk so used can either be incinerated or fed into a boiler; thus
completely destroying of color and associated organic impurity.
ADVANTAGES OF THE PRESENT INVENTION
I) Duration of the treatment is reduced from months to few hours.
II) Considerable reduction in electrical energy expenditure.
III) The whole operation can be designed as a continuous process.
IV) The reduction in BOD has been achieved from 5000 to 60 in the case of effluent
discharge after methanogenesis. In the direct discharge from the distillery with an
initial BOD i.e., 30 to 50,000 the reduction achieved is of about 386mgl/lt.
V) Foul odors around the distillery are totally eliminated.
VI) Since the color is totally removed there is no color seepage to ground water.
VII) The chemicals used are absolutely non toxic and easily available. Filtering medium
is also commonly available. Course materials such as paddy husk, which can be
later, burnt by feeding to the boiler thus reducing the organic insoluble complex to
CO2 and H2O.
VIII) Most important advantage of the process is minimal amount of ground or surface
water tapped throughout the day.
Table-1 compares parameters of distillery digester effluent with treated distillery effluent.

Table-2: Showing optical density and percentage solid separated of distillery effluent on treatment.

WE CLAIM
1 An eco-friendly process for removal of color, odor and reduction in Biological
Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery
effluent, said process comprising the steps of;
a) adding to the distillery effluent one or more alkali metal salts and /or one or more alkaline earth metal salts with alkali hydroxide to form a precipitate for entrapping inorganic / organic impurities, separating the precipitate thus formed and optionally, repeating the above step one or more times till the effluent contains less than 8 to 9 % of total solid content and the color of supernatant is light yellow;
b) adding to the supernatant of step (a), with alum and alkali to form a precipitate entrapping remaining inorganic / organic impurities and thereby formed a substantially colorless, odorless effluent; and
c) filtering the substantially colorless odorless effluent of step (b), using filtering media to obtain substantially colorless odorless treated effluent having low value of COD and BOD.

2 A process as claimed in claim 1, wherein the metals of alkali metal salt are selected from Li, Na, K, Rb, Cs and Fr.
3 A process as claimed in claim 1, wherein the metals of alkaline earth metal salts are selected from the Be, Mg, Ca, Sr, Ba and Ra.
4 A process as claimed in claim 1 wherein in step (a), the precipitate thus formed contains inorganic / organic color impurities.
5 A process as claimed in claim 4, wherein the precipitate thus formed contains organic color impurities.
- 6 A process as claimed in claim 1, wherein the distillery effluent has BOD value in
the range of 3500 to 7000 mg/L.
7 A process as claimed in claim 6, wherein the distillery effluent has BOD value in the range of 5000 mg/L to 6000 mg/L.
8 A process as claimed in claim 1, wherein the distillery effluent has COD value in the range of 11000 to 17000 mg/L.

9 A process as claimed in claim 8, wherein the distillery effluent has COD value in the range of 14000 to 14500 mg/L.
10 A process as claimed in claim 1, wherein in step (a), sal of calcium is used with sodium hydroxide.
11 A process as claimed in claim 1, wherein in step (a), pH value is in the range of 6 to 10.0.
12 A process as claimed in claim 1 wherein in step (a), about 7.5 % calcium salt and of about 5 % NaOH is used.
13 A process as claimed in claim 1 wherein in step (b), about 5 % alum and of about 0.5% alkali is used.
14 A process as claimed in claim 1 wherein in step (c), substantially colorless, odorless treated effluent has an optical density of 100 %.
15 A process as claimed in claim 1 wherein in step (c), substantially colorless, odorless treated effluent obtained has BOD value 100 to 120 times lower and COD values 65 to 85 times lower from the respective initial values of distillery effluent.
16 A process as claimed in claim 1 wherein in step (c), filtering media is selected from the group comprising coarse filter paper, Bagas or paddy husk.
17 A process as claimed in claim 1, wherein time period .for treating the distillery effluent is in the range of 1 hour 10 minute to 6 hours.
18 A process as claimed in claim 1, wherein time period for treating the distillery effluent in step (a) is in the range of 1 hour to 4 hours.
19 A process as claimed in claim 1, wherein time period for treating the distillery effluent in last step is in the range of 10 minute to 3 hours.
20 A process as claimed in claim 1, wherein the step (a) is repeated two times, if the solid content in the distillery effluent exist more than 65 to 85 %.
21 A process as claimed in claim 1, wherein the step (a) is repeated three times, if the solid content in the distillery effluent exist more than 8 to 9 %.

22 An eco-friendly process for removal of color, odor and reduction in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) of a distillery effluent substantially as herein described and illustrated therein.

Documents:

060-che-2004-abstract.pdf

060-che-2004-claims filed.pdf

060-che-2004-claims granted.pdf

060-che-2004-correspondnece-others.pdf

060-che-2004-correspondnece-po.pdf

060-che-2004-description(complete)filed.pdf

060-che-2004-description(complete)granted.pdf

060-che-2004-form 1.pdf

060-che-2004-form 19.pdf

060-che-2004-form 26.pdf

060-che-2004-form 3.pdf

060-che-2004-form 5.pdf

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Patent Number

212473

Indian Patent Application Number

60/CHE/2004

PG Journal Number

07/2008

Publication Date

15-Feb-2008

Grant Date

03-Dec-2007

Date of Filing

27-Jan-2004

Name of Patentee

J.S.S. MAHAVIDYAPEETHA

Applicant Address

S.S. NAGAR, MYSORE 570 015,

Inventors:

#	Inventor's Name	Inventor's Address
1	VENKATACHALA SREENIVASA DATTAMUTHY	J.S.S. COLLEGE OF PHARMACY, S.S. NAGAR, MYSORE 570 015,
2	HOSAKOTE GURUMALLAPPA SHIVAKUMAR	J.S.S. COLLEGE OF PHARMACY, S.S. NAGAR, MYSORE 570 015,
3	BAHUBALI GUNDAPPA NAGAVI	J.S.S. COLLEGE OF PHARMACY, S.S. NAGAR, MYSORE 570 015,
4	SETHU MADHAVA SAMEERA	J.S.S. COLLEGE OF PHARMACY, S.S. NAGAR, MYSORE 570 015,

PCT International Classification Number

C02 F 11/14

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA