Performance Evaluation of Brewery Biological Wastewater Treatment Plant

Brewing is the process is for production of beer [1,2]. It is said that for every 1 liter of beer production approximate 10 liters of water is used [3]. The water in any brewery is typically used for brewing, rising and cooling process [3]. The various steps that are involved in brewing process are malt production and handling, worth preparation, fermentation, filtration, CIP and finally packaging [1,4-6]. The quality and quantity of effluent generated through various processes depend upon the water consumed in each process [4]. Brewery effluent is characterized by high organic load and high acidic content [2,7-10]. It consists of soluble sugar, soluble starch, carbohydrates, ethanol, volatile fatty acid, suspended solids and yeast etc [11,3,6]. Most of the organic present in brewery wastewater is biodegradable. COD to BOD ratios ranges from 1.5 – 2.0 [11,10]. Several methods were used to treat the effluent generated from the brewery. Physical method is used to remove the coarse matter present in effluent. Chemical method can be employed to remove the suspended impurities. Biological treatment method like anaerobic and aerobic treatment results in removal of high COD and BOD present in wastewater [4,3]. Wastewater from brewery doesn’t contain adequate quantity of nitrogen required for biological oxidation due to which external nitrogen nutrients are required to be added into the aeration basins [11]. Anaerobic, aerobic and reverse osmosis treatment provides better removal efficiency for brewery effluent [1,2]. Bio-remediation methodology with anaerobic treatment can remove 90-98% of high COD present in brewery wastewater. Pseudomonas, gram negative bacteria has been found to act actively at a very high pH, bringing pH down from 10.2 to 8.67 [5]. It has tested to reduce concentration of carbohydrates by 54% and proteins by 25% in brewery effluent. The study of microbial consortia (Cronobacter sp. strain NGS4, Pseudomonas fluorescent NGS5, and Aeromonas sp. strain NGS7) with optimal oxygen flow (aeration), retention time and temperature showed reduction of COD by 67%, BOD by 79% and TSS by 50% [12]. The factors that affect the microbial ecology and characteristics of anaerobic reactors include Organic Loading Rate (OLR), Hydraulic Retention Time (HRT) and up low velocity [13]. Anaerobic Hybrid Reactor (AHR) under thermophilic condition (55°C) with an 5.5g COD/ day OLR and 10 days HRT offered 90% COD removal with high methane yield i.e.0.32 g CH4 /g COD removal was established through experimentation [14]. Under mesophilic conditions (35°C) high TCOD removals ranging between 4286% at a OLRs of 0.5-24.0 Kg COD m-3d-1 and HRT 4-6 hours were achieved through studies [13]. Operational study for 2 years in Expanded Granular Sludge Bed reactor depicted 95% of COD conversion into gas and solid digestion with proper COD solubility and efficient EGSB mixing [13]. 98% COD, 99% TSS and 98% BOD removal rate were observed in brewery effluent treatment plant having UASB reactor followed by Sequential Batch Reactor (SBR) [15]. The advanced treatment technologies like SBR and membrane technologies provide an effective method of treating effluent. Additional advantage of latest technology is less power usage and reduction in plant footprint area [16]. The comparative performance evaluation of aerobic treatment technologies on food industry effluent depicted highest BOD and COD reductions in case of fluidized aerobic biological reactor (FABR) than activated sludge process (ASP), stabilization pond and rotating biological contactors. The COD, BOD removal efficiencies through FABR was 85% and 91% respectively. ASP process showed 84% reduction in BOD and 90% reduction in COD. The reduction in case of Stabilization Pond and RBC was less than 79% [17]. Energy saving analysis at sewage treatment plant demonstrated that power consumption can be reduced by 7 to 17% by controlling settings for MLSS, Return Sludge Ratio and Rector Dissolved Oxygen [18]. Volume 3 Issue 1 2018