Case Study Stabilization of Effluent Treatment Plant

Transcription

1 Case Study Stabilization of Effluent Treatment Plant Version 1.0: March 2014 Page 1

2 CASE STUDY STABILIZAION OF EFFLUENT TREATMENT PLANT Project Name: Stabilization of Effluent Treatment Plant - Brewery Department : Effluent Treatment Plant (ETP) Focus Area: ETP Stabilization at full load Product/Process: Extensive sampling, Environmental engineering and analysis. Page 2

3 Table of Contents LEGEND:... 4 Company profile... 5 Business situation... 6 Technical Situation... 7 Solution... 7 OBJECTIVE... 8 PRODUCT, WATER USE AND WASTE GENERATION... 8 DESCRIPTION OF EFFLUENT TREATMENT PLANT... 9 SELECTION OF EFFLUENT QUALITY PARAMETERS AND LOCATION OF STATIONS FOR COLLECTION OF EFFLUENT SAMPLES RECOMMENDATIONS IMPLEMENTATED BioZYM AqBON ANALYSIS OF SAMPLES OF EFFLUENT AND PRESENTATION OF DATA Turbidity Values TSS values TSS VALUES: COD values TDS values: CONCLUSION Page 3

4 LEGEND: ETP Effluent Treatment Plant mg/l - Milligram per Liter ph Potential of Hydrogen Ion Concentration TSS Total Suspended Solids BOD Biological Oxygen Demand COD - Chemical Oxygen Demand DO Dissolved Oxygen TDS Total Dissolved Solids NTU Nephelometric Turbidity Unit MLSS - Mixed Liquor Suspended Solids MLVSS - Mixed Liquor Volatile Suspended Solids SVI - Sludge Volume Index F/M Ratio Food to Micro Organism Ratio HRT Hydraulic Detention Time CIP Cleaning in Place R. O. Reverse Osmosis UASB Reactor Up Flow Anaerobic Sludge Blanket Reactor Page 4

5 Company profile GreenErect is a provider for environmentally and eco-friendly solutions. GreenErect is a fusion between a range of consulting, development and manufacturing firms. We provide environment friendly solutions that deliver outstanding results. Greenerect provides solutions to meet demands and needs without depleting natural resources. GreenErect s ENVIRONMENT DIVISION Team is a consortium of highly qualified and experienced technical experts to deal with effluent treatment of major water intensive industries namely, Pulp & Paper, Brewery, Distillery, Food Processing, Beverage, Sugar, Pharmaceutical, Chemical, Integrated Iron and Steel, Textile, etc. Keeping pace with the developments in environmental engineering and technologies, GreenErect ventures for proven and advanced environmental technologies depending upon the need of the industries. GreenErect encourages eliminating/ reducing the process waste at source of its generation for salvage, recovery, or reuse and also segregating nonpolluting stream from polluting stream of effluent which can lower investment costs as well as operating costs for primary (Physical & Chemical), secondary (Biological Aerobic/Anaerobic) and tertiary units of ETPs. Confident with its engineering capabilities, GreenErect designs to minimize investment and operating costs by selecting and applying the most suitable and accurate technological solutions for its customers. GreenErect provides a unique combination of environmental engineering, enzymes, and microbial cultures that are manufactured in house for pretreatment, primary treatment and secondary treatment of the effluent treatment plants (ETP s) life cycle. GreenErect has a proven and time tested solution for enhanced stabilization of ETP at its primary and secondary treatment levels with the help of balanced and controlled blend of high potency bacterial culture designed and developed exclusively for the purpose for increasing the reliability and efficiency of the ETP. A multi-enzyme concentrate with a unique formulation consisting of surfactants along with enzymes helps to improve the efficiency of the ETP by breaking down the larger organic molecules to smaller ones and thus can be easily digested by the microbes in the ETP accelerating the process of reduction of BOD, COD, TSS and TDS. Page 5

6 Business situation During the last two decades the brewing industry has shown increasing awareness for environmental protection and the need of sustainable production processes. Public awareness and implementation of stringent environmental legislation have been important drivers for the brewing industry to invest in effluent treatment. The quality and quantity of brewery effluent can fluctuate significantly as it depends on various different processes that take place within the brewery (raw material handling, work preparation, fermentation, filtration, CIP, packaging. etc). Organic components in brewery effluent (expressed as BOD & COD) are generally easily biodegradable as these mainly consist of sugars, soluble starch, ethanol, volatile fatty acids, etc. This is illustrated by the relatively high BOD/COD ratio of The brewery solids (expressed as TSS) mainly consist of spent grains, kieselguhr, waste yeast and ( hot ) trub. Brewery effluent ph levels are mostly determined by the amount and type of chemicals used at the CIP units (e.g. caustic soda, phosphoric acid, nitric acid etc). Knowledge about environmental emissions (e.g. effluent quality and quantity) has become the management information, which may help to improve the efficiency of in-plant brewery processes (minimize product losses, spill of water and energy). The role of biological effluent treatment needs special attention. Combining anaerobic treatment with aerobic treatment integrates the advantages of both processes. Reduced energy consumption (net energy production), reduced biological sludge production and limited space requirements, are the advantages of great importance of the combined treatment. The combination allows for significant savings on operational costs as compared to complete aerobic treatment; without compromising the required discharge standards. Some of the most common problems associated with brewing industry: High ph detergents, which give high COD loading to the effluent Wide variation during the day as to the effluent quality and ph Restrictions to discharge limits as directed by the State Pollution Control Board. Limitations imposed on water abstraction Space constraints and other limitation on site to install new equipment In the Brewery Industry therefore effective effluent management is gaining more importance by the day to improve the cost effectiveness of their production process as well as to avoid hefty discharge penalties. Page 6

7 Technical Situation One GreenErect customer, a multinational brewer, is one of the leaders in brewing industry having over 22 breweries in India. One brewery had effluent volume of about KLD. They had a welldesigned ETP of appropriate size to handle regular loads as well as shock loads. High COD loads became unmanageable at the primary level with permissible limit of the USB reactor being 6000 mg/l. Also they had a recurrent problem of high COD and BOD even after primary and secondary treatment. The Pollution Control Board was insisting on improving the ETP performance. Solution An approach was made to GreenErect to see if it could solve the problems faced by the brewer. Technical staff of GreenErect visited site to assess the issues. The following simple but effective approach was put in practice Feasibility Study - A site inspection & discussions with staff to gain full understanding of the treatment process followed. Confirmation of the variances in volumetric flows and the performance criteria required. Evaluation of waste water inputs and outputs records Evaluation of performance of the ETP as per existing design of each of its unit operations Identification of the problem areas Recommending remedial measures to improve efficiency of the ETP Adjusting/ Optimizing various design parameters on site namely, MLSS, MLVSS, SVI, F/M Ratio, Volumetric Loading, Recirculation Ratio, HRT, Oxygen Requirement, Air Requirement, BOD and COD removal efficiency, etc. Once the problem areas had been identified and confirmed, a series of laboratory evaluations was conducted over a period of two weeks to ensure that appropriate treatment programs were selected whatever the substrate treatability. Page 7

8 OBJECTIVE The objective of the project: 1. Treat effluent and maintain a COD of less than 6000 at the inlet of the USB reactors. 2. Maintain Turbidity of less than 10 NTU at the outlet of the secondary clarifier. 3. Maintain COD less than the permissible limit. 4. Maintain TSS less than the permissible limit. PRODUCT, WATER USE AND WASTE GENERATION Brewing is intrinsically a major water intensive industry. In the process, large quantities of water are used for the production of beer itself, as well as for washing, cleaning and sterilizing of various units after each batch are completed. Commonly available best available technologies require in excess of 4 litres of raw water per litre of beer produced (Specific water use). The brewery is engaged in production of 0.12 million hectare litre/ month of beer using malt (@ 990 tons/ month), sugar (@ 506 tons/ month), rice flakes (@ 62 tons/ month), yeast (@ tons/ month) and kieselguhr (214 tons/ month). The brewery uses water of about 1800 m 3 / day. Table below shows details of the waste generated from the brewery and current disposal facility/ practice. Table: Waste Generation from Different Sources of the Brewery Sl. No. Name of the solid/ semi solid/ Volume of generation Mode of disposal liquid waste 1 Waste effluent 960 to 1200 m 3 / day Treatment & reuse 2 Spent grains 2400 Tons/ day Cattle feed 3 Spent hops 6.6 Tons/ day Disposal to ETP 4 Spent yeast 114 Tons/ day Reused 5 Caustic & Cleaners = 4.5 Tons/ day ETP 6 Kieselguhr sludge 214 Tons/ day ETP 7 Sludge of effluent treatment plant 20 Tons/ day Sludge drying bed Page 8

9 DESCRIPTION OF EFFLUENT TREATMENT PLANT With the growing crisis of ground water and surface water in certain regions of India, it has become necessary for major water intensive industries to introduce reuse/ recycling of treated effluent back into the process and other utility departments. The Brewery already has elaborate primary, secondary and tertiary effluent treatment facility within its plant premises along with an additional facility to further polishing a major quantity of the tertiary treated effluent through series of filtration systems of different grades and reverse osmosis (R. O.) plants. Treated effluent, after reverse osmosis, is reused in different utility departments. Remaining treated effluent after tertiary treatment is stored in lagoons for gardening, firefighting, etc. During the peak season, the quantity of effluent generated is around 1500 m 3 / day. Average effluent flow generation varies between 960 to 1200 m 3 / day or 40 to 50 m 3 / hour (40 to 50 KL/ hour). The effluent treatment plant consists of the following unit operations: PRIMARY TREATMENT SECONDARY TREATMENT TERTIARY TREATMENT Screen Chamber Equalization Tank # 1 Equalization Tank # 2 Primary Clarifier Buffer Tank Up-flow Anaerobic Sludge Blanket (UASB) Reactor # 1 Up-flow Anaerobic Sludge Blanket (UASB) Reactor # 2 Aeration Tank # 1 Secondary Clarifier # 1 Aeration Tank # 2 Secondary Clarifier # 2 Tertiary Clarifier # 3 Multi Grade Filter Activated Carbon Filter Bucket Filter Ultra filter Collection Tank Reverse Osmosis (R. O.) Plant Treated Water Tank Page 9

10 Detailed flow diagram of the effluent treatment plant is depicted in Figure 1. FIG 1: FLOW DIAGRAM OF EFFLUENT TREATMENT PLANT OF THE BREWERY SELECTION OF EFFLUENT QUALITY PARAMETERS AND LOCATION OF STATIONS FOR COLLECTION OF EFFLUENT SAMPLES The criteria parameters selected for conducting performance study of the effluent treatment plant are the following: I. ph II. Total Suspended Solids (TSS), mg/l III. Total Dissolved Solids (TDS), mg/l IV. Turbidity, NTU V. Dissolved Oxygen (DO), mg/l VI. Biochemical Oxygen Demand (BOD), mg/l Page 10

11 VII. Chemical Oxygen Demand (COD), mg/l Apart from the above mentioned criteria parameters, some essential parameters are also selected to check the adequacy of the anaerobic and aerobic treatment unit operations. These are as follows: 1. Mixed Liquor Suspended Solids (MLSS), mg/l 2. Mixed Liquor Volatile Suspended Solids (MLVSS), mg/l 3. Sludge Volume Index (SVI), ml/ gm Locations of the sampling stations are as follows: Primary Treatment i. Raw/ untreated effluent receiving sump ii. Downstream (Outlet) of the equalization tank # 1 & 2 iii. Downstream (Outlet) of the primary clarifier iv. Downstream (Outlet) of the buffer tank Secondary Treatment i. Downstream of the UASB Reactor # 1 and UASB Reactor # 2 (i.e. at the inlet of Aeration Tank # 1 ii. Downstream (Outlet) of Aeration Tank # 1 iii. Downstream (Outlet) of Secondary Clarifier # I iv. Downstream (Outlet) of Aeration Tank # 2 v. Downstream (Outlet) of Secondary Clarifier # II Tertiary treatment i. Downstream (Outlet) of Tertiary clarifier # 3 ii. Downstream (Outlet) of Multi Grade Filter (MGF) iii. Downstream (Outlet) of Activated Carbon Filter (ACF) iv. Downstream (Outlet) of the Bucket Filter (BF) v. Downstream (Outlet) of Ultra Filtration Unit (UF) vi. Downstream (Outlet) of Reverse Osmosis (RO) plant # I(Permeate) vii. Downstream (Outlet) of reverse osmosis (RO) plant # I(Reject) Page 11

12 RECOMMENDATIONS IMPLEMENTATED a) On site optimization and/ or, re implementation designed data in respect of MLSS, MLVSS, SVI, F/M Ratio, Volumetric Loading, Recirculation Ratio, HRT, Oxygen Requirement, Air Requirement, etc. b) Dosing of 6ppm in the equalization tank. c) Dosing of 3 ppm in the primary clarifier. d) Dosing of 135mg in the primary clarifier. e) Recirculation matrix fixed for UASB Reactor f) Recirculation matrix fixed for sludge from clarifiers to aeration tanks. g) Dosing of AqBON@ 20ppm at secondary clarifiers. BioZYM BIOZYM is a multi-enzyme concentrate created in a cold-fermentation process. BIOZYM consists of concentrated organic enzymes, powerful organic surfactants & micro-nutrients. Organic and completely biodegradable Non-toxic, non-hazardous, non-flammable BIOZYM mode of action is biological rather than chemical. The active ingredient is a biological complex, which stimulates natural microbial processes responsible for the effective breakdown of a wide variety of industrial organic wastes. BIOZYM is specially formulated with biodegradable surfactants and wetting agents that rapidly emulsify grease and sludge, permitting the product to penetrate and work rapidly and efficiently. BIOZYM creates conditions in which naturally occurring beneficial micro-organisms can thrive. AqBON AQBON unique formula is based on 35% hydrogen peroxide that has been put through a specialtreatm entthe result of which is a powerful broad spectrum disinfectant that is completely safe to the environment, yet leaves no unpleasant tastes or odours. AQBON has proven bactericidal, algicidal, fungicidal, sporicidal and viricidal efficacy. Areas of use: CIP Process: RO Plant : - Replacement of caustic. - Replacement of chlorine - Removal of Biofilms - Cleaning of membranes Page 12

13 Disinfection of effluent water: Treatment of service water:- Disinfection of service water - bores. - Disinfection of filters. - Service water - buffer - tanks - Service water - network Brewery water treatment : - Disinfection of brewery process water. - Disinfection of filters. - Brewery water - buffer - tanks. Page 13

14 ANALYSIS OF SAMPLES OF EFFLUENT AND PRESENTATION OF DATA Samples of effluent collected during the study were analyzed in the in-house laboratory of the industry in respect of ph, total suspended solids (TSS), total dissolved solids (TDS), turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), mixed liquor suspended solids (MLSS), mixed liquor suspended volatile solids (MLVSS), sludge volume index (SVI), etc. Samples of effluent were collected from the upstream and downstream of the units to assess the adequacy of the different treatment units of the ETP. Samples of effluent were collected for the period from 19/09/2013 to 29/09/2013 was analyzed. Below is the graphical representation of Turbidity, TSS and COD values obtained during sampling of effluent at different stages of treatment. BOD, COD and Turbidity are mostly dependent on TSS, so graphical representation of BOD, COD and Turbidity shall also follow the similar pattern as that of the TSS. It may be seen that the sharp spikes represents shooting up of COD and TSS inside the equalization tanks. [NOTE: In the graphs below, Sampling Station 1: Raw/ Untreated Effluent Receiving Sump; Sampling Station 2: Outlet of Equalization Tank (or, Inlet of Primary Clarifier); Sampling station 3: Outlet of Buffer Tank; Sampling Station 4: Outlet of two nos. of UASBs (Or, Inlet of Aeration Tank # 1); Sampling Station 5: Outlet of Secondary Clarifier # 1 (Or, Inlet of Aeration Tank # 2); Sampling Station 6: Outlet of Secondary Clarifier # 2 (Or, Inlet of Tertiary Clarifier # 3); Sampling Station 7: Outlet of Tertiary Clarifier # 3.] Page 14

15 Turbidity Values: LESS THAN 5 NTU ACHIEVED AFTER TERTIARY CLARIFIER # 3 TSS values: Page 15

16 TSS VALUES: Page 16

17 COD values: Page 17

18 TDS values: Page 18

19 CONCLUSION a) COD less than 6000 were achieved at the inlet of the USB reactors in spite of high COD and TSS at the equalization tanks due to large deposits of sludge. b) Turbidity values of less than 5 NTU achieved at outlet of tertiary clarifier # 3. c) The above results clearly show TSS and COD values were well below the corresponding permissible limits of 100 mg/l and 250 mg/l respectively. d) There is almost no reduction of TDS has taken place during the stabilization process. e) Stabilization of the tertiary effluent treatment system was not included in the terms of reference (TOR) of the stabilization project. Hence, no result regarding the performance of the tertiary effluent treatment system has been shown. Page 19