BREWERIES, WINERIES & DISTILLERIES
BREWERIES, WINERIES & DISTILLERIESByAnshumaan DeyM.Tech, Chemical EngineeringGuru Gobind Singh Indraprastha UniversityINTRODUCTIONThe range of products from distilleries include industrial alcohols, rectified spirit, absolute alcohol, beverage alcohol, etc.All the products are obtained through the biochemical process of fermentation by yeast, using carbohydrates as raw materials.All the products contain ethyl alcohol in different proportions Origin and characteristics of breweries wastesMaking of beer essentially consists of 2 stages:Preparation of malt from grains like barley.Brewing the barley.The malt from the malt house is then transported to the brewing section, where wort, the medium of fermentation is prepared.Characteristically, the brewery waste contains a large amount organic soluble solids indicated by a high BOD in the order of 400-800 mg/L and low suspended solids concentration.COMPOSITION OF MALT HOUSE AND COMBINED BREWERY WASTEMalt House WasteBrewery WastepH6.9 9.54.0 7.0COD (permanganate value), mg/L 31 17530 1225 BOD, mg/L20 20470 3000Total Solids, mg/L428 700272 2724Suspended Solids, mg/L22 3916 516Total Nitrogen (N), mg/L14 56 7 42 Origin and characteristics of DISTILLERIES wastesThe beverage alcohol industries utilize different grains, malted barley and molasses as raw materials.The preparation of mash consists of:Preparation of green malt.Preparation of cooked slurries of grains.Mixing of above two followed by pH adjustment, and nutrient (ammonium salts and phosphates) supplementation.In molasses distilleries, the preparation of mash consists of:Dilution by water to a sugar content of about 15%.pH adjustment to 4.0 4.5 to prohibit bacterial activities.Nutrient addition.The alcohol is stripped in a tower leaving a spent wash which is the major polluting component of the distilleries, and it is reported to be 10 15 times the final product in volume.CHARACTERISTICS OF COMPOSITED COMBINED WASTE, SPENT WASH & YEAST SLUDGE FROM DIFFERENT INDIAN DISTILLERIESYeast SludgeCombined WasteSpent WashSpent WashpH4.83.9 4.33.5 3.654.0 4.5Temperature, oC- --90 95COD, mg/L36800027900 7300011800070000 151200BOD, mg/L16500012230 400004138028000 80000Total solids, mg/L-16640 260009900059100 114500Suspended Solids, mg/L730004500 120003501000Total Nitrogen, mg/L--113514800 19000Alkalinity-380 510--Colour--Dark BrownDark BrownDO--NIL-Rate of waste flow-0.9 1.0 MLD-0.82 MLDOrigin and characteristics of wineries wastesThe wineries utilize the fruit juices as the raw materials.The first operation in any winery is the pressing of fermenting juice from the fruits like grape, mahua, etc.The second stage in any winery consists of fermentation of the juice.In the third stage, i.e. in the brandy plant, wine of either type or the fermentation residue in the wine making is distilled to obtain brandy.CHARACTERISTICS OF COMBINED WASTES FROM BREWERY, WINERY AND FOOD PROCESSING UNITS.Temperature20 29 oCColourBrownish YellowpH4.0COD, mg/L1800 3000BOD, mg/L1500 2000Dissolved Solids, mg/L6800 9400Suspended Solids, mg/L15 17 TREATMENT OF WASTESUsually, the biological treatment is accomplished by two stage process for 90 94% BOD reduction.The yeast sludge from the distilleries which contains very high suspended solids and BOD and is rich in proteins, carbohydrates, vitamins, may be released separately for by product recovery.The raw spent wash with low pH, high dissolved solids, high temperature, high sulphates, and high BOD is not amenable to aerobic biological treatment. TREATMENT OF BREWERY WASTE
Both closed anaerobic digestion and open anaerobic lagooning has been tried in INDIA as a means of anaerobic treatment.For a BOD reduction of 90.8% a BOD loading of 2.5 kg/m3/day and a detention time of 15 days is suggested by Subbarao et. al.A digester with a BOD loading of 3.01 kg/m3/day, and operating in mesophilic range with 10 days detention time was reported to have reduced the initial BOD by 90% by Sen and Bhaskaran.WASTE TREATMENT IN A LARGE DISTILLERY COMPLEX
Production of H2S impairs the anaerobic digestion, as soluble sulphides are toxic to the micro organisms.About 90-95% BOD can be achieved in a two stage anaerobic lagoon system.BOD reduction of 85.5% with a detention time of 60 days and a loading rate of 0.67 kg of BOD/m3/day in the 1st stage, and BOD reduction of 65.5% with a detention time of 40 days and a loading rate of 0.15 kg of BOD/m3/day in the 2nd stage is reported.About 90% of BOD removal can be accomplished in aerated lagoons with a detention time of 20-28 days.The same degree of treatment can be achieved with 1:1 dilution at a detention time of 15-16 days.The BOD removal rate constant, K, for the anaerobic lagoon effluent is found to vary from 0.01 to 0.05/day; with 1:1 dilution BOD removal rate constant was found to improve to 0.06-0.08/day.Oxidation ditches with 50-60 hours detention time and MLSS concentration of 4000 mg/L are also claimed to reduce the BOD of the anaerobic treatment effluent by about 90%.In a laboratory study, about 56.2% reduction of BOD is obtained when the distillery waste is used as the medium for growing an adapted variety if yeast.
REFERENCESWaste water treatment 3rd ed., by M.N. Rao and A.K. Dutta, Oxford and IBH.Environmental Engineering, by Peavy, Rowy and Tchobanogolous, Mc Graw Hills International Edition.THANK YOU