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TABLE OF CONTENTS
1. Introduction ................................................................................................................................... 3
2. Basics of Wastewater Treatment .............................................................................................. 3
2.1 Typical Brewery Treatment Train ................................................................................ 5
3. Common Wastewater Parameters ........................................................................................... 5
3.1 What is BOD? .............................................................................................................. 5
3.2 Why is BOD regulated? ............................................................................................... 6
3.3 What is COD ................................................................................................................. 6
3.4 What is pH? ................................................................................................................. 6
3.5 Why is pH regulated? ................................................................................................... 6
3.6 What is TSS? ............................................................................................................... 6
3.7 Why is TSS regulated? ................................................................................................. 7
3.8 What About Nitrogen and Phosphorus? .................................................................... 7
3.9 Why is temperature important? ..................................................................................... 7
4. What is Brewery Wastewater? ................................................................................................ 8
5. How BioGill Treats Brewery Wastewater ............................................................................... 9
5.1 BioGill Maintenance Guide ....................................................................................... 11
5.2 BioGiIl System Sizing Guide .................................................................................... 11
6. Tips & Hints .............................................................................................................................. 13
6.1 Floor drains ................................................................................................................. 13
6.2 Side Streaming .......................................................................................................... 13
6.3 Screens ...................................................................................................................... 13
6.4 pH Dosing ................................................................................................................. 14
6.5 Flow Balancing ........................................................................................................... 14
7. Next Steps .............................................................................................................................. 14
Brewing beer is a water intensive process that generates significant volumes of high strength wastewater containing elevated levels of Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS). As a result, many breweries incur costly high strength surcharges from local utilities, pay to truck wastewater offsite, or contend with other onsite challenges related to odors and wastewater storage.
This guide is designed to give craft brewery owners and operators insights into:
> Why onsite wastewater treatment system can be good for business.
> Minimizing surcharges and offsite hauling fees.
> Factors to consider when evaluating onsite treatment systems.
> Options for wastewater treatment onsite.
> How a BioGill onsite treatment system works.
Regulatory requirements for wastewater treatment are set at the local, state, and/or national level. Regulations vary based on the location of discharge, which may be to the local sewer system and public wastewater treatment facility, to surface waters, or to land for irrigation.
For systems discharging directly to the environment, discharge regulations are in place to protect the health of soil and water systems. Requirements for sewer discharge are designed to ensure that these wastewater streams do not harm infrastructure, personnel nor disrupt or overload the treatment facility’s own processes.
Most breweries discharging to sewer are subject to certain minimal pre-treatment requirements that often include pH correction and sometimes flow equalization. As brewery wastewater is high in strength and can represent a significant impact on the operation of local wastewater treatment plants, local utilities may charge high strength surcharges and limits. This is to cover the costs of treatment, prevent overloading of the facility’s treatment capacity, or to incentivize breweries to install further onsite wastewater treatment to reduce wastewater strength and demand on the public facility.
In these cases, it can often make sense to install a more advanced onsite wastewater treatment system that will reduce monthly utility fees, allow for expansion in brewery production, and provide a means of control over future wastewater-related operational costs.
1. INTRODUCTION
As a first step, it’s helpful to understand the basics of wastewater treatment. The key principle is to remove pollutants from the wastewater in the most economical and practical way possible, with treatment split into three successive categories:
> Primary> Secondary, and> Tertiary
2. BASICS OF WASTEWATER TREATMENT
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PRIMARY SECONDARY TERTIARY
Physical and/or chemical solids
separation.Flow equalization.
Neutralization (pH control).
Biological removalof organic
material (BioGill).
Final removal ofremaining solids/
nutrients.Disinfection if
required.
Depending on the wastewater discharge location, a treatment process may require one, two, or all three of these stages.
PRIMARY
In the primary stage, fluctuations in flow and loading are mitigated, pH is neutralized, and physical and/or chemical steps are used to remove large and settleable solids and fat, oil, and grease, known as FOG. Physical processes used in primary treatment may include screening, filtering, sedimentation and floatation. Chemicals such as flocculants and coagulants may also be used to increase the effectiveness of physical separation processes.
There is a limit to the effectiveness of primary treatment technologies, as only a certain proportion of the pollutants in each wastewater stream are solid particles. So, even if all solids present in the wastewater are removed, there’s a high chance that a significant amount of soluble pollutants are also present. When primary treatment can no longer effectively improve water quality, secondary treatment is used to remove soluble or dissolved pollutants.
SECONDARY
Secondary treatment is achieved through biological means. Microorganisms are nature’s best nutrient recyclers and decomposers, providing the biological engine behind many forms of wastewater treatment.
As a secondary treatment technology, BioGill utilizes microorganisms to consume and remove soluble pollutants. Just as humans require a balanced nutritious diet, microbes also need a balance of nutrients to grow and treat wastewater effectively. Therefore, some wastewater streams require small amounts of nutrients to be added in at this stage. The most common of these are nitrogen and phosphorus and are relatively inexpensive.
TERTIARY
Tertiary treatment can be thought of as polishing processes. These include further removal of solids or specific nutrients and disinfection when required. Processes may include reverse osmosis or ultrafiltration. Tertiary treatment is typically required for water re-use and discharge to surface waters.
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2.1 Typical Brewery Treatment Train A wastewater treatment process is often referred to as a “treatment train”. An onsite treatment train for a brewery may require the following, depending upon site specific requirements:
In treating wastewater, it is important to understand several key parameters and why they are regulated in terms of trade waste discharge to sewer. Requirements can vary from one water authority to the next. Local, state, and/or federal regulations may vary by location and jurisdiction.
Two breweries located near each other may be subject to very different limits and requirements based on their size, discharge location and the capacity of their local public wastewater treatment facility and its rate structure.
3.1 What is BOD?Biochemical Oxygen Demand (BOD) is a measure of the biologically degradable organic content in a wastewater stream. Organic compounds such as sugar, alcohols and volatile fatty acids contribute to BOD. One useful way to consider BOD, is to think of it as little bits of bacteria food. As bacteria consume the BOD, the amount of oxygen used by the bacteria via respiration can be measured. This gives an approximation of the amount of the ‘bacteria food’ in the wastewater.
The most common type of BOD test is performed over 5 days at a constant temperature of 20°C │ 68°F. This makes BOD testing a more challenging and expensive measurement tool. With BOD measurements, you don’t get your results for more than five days after you take the sample. This limits your ability to make timely changes to lower the BOD.
3. COMMON WASTEWATER PARAMETERS
INFLUENT SOLIDSREMOVAL
SOLIDSREMOVALBIOGILL DISCHARGE
EQUALIZATIONpH &
NUTRIENTDOSING
SECONDARYPRIMARY
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3.2 Why is BOD regulated?Public wastewater treatment facilities are designed to treat a certain amount of BOD per day. This amount is linked to the size of the population and industrial contribution and is often referred to in terms of equivalent population. A value of 50-120 grams (1.8 – 4.2oz) BOD per person per day for domestic sewage is typical.
The amount of BOD contributed by even a small brewery producing 2,000 bbl/year could be the equivalent BOD loading of more than 150 residents. As such, in smaller towns and communities, brewery wastewater can represent a significant strain on the capacity and operations of the local public wastewater treatment facility, particularly if the brewery was established or expanded after the facility was built.
High BOD discharged into a sewer system can also cause in-sewer fermentation, oxygen consumption, and pH reduction, which can cause potentially serious structural damage to sewer piping as well as creating a hazardous environment for sewer workers. When discharged to surface waters, wastewater high in BOD will cause consumption of oxygen in the receiving water, which can kill aquatic plants, fish, and other organisms. Essentially, the higher the BOD the greater the negative impact on the environment.
3.3 What is COD?Chemical Oxygen Demand (COD), is the total measurement of all chemicals in the wastewater that can be oxidized. In contrast to BOD, this testing method measures both biodegradable and nonbiodegradable compounds. The test is much quicker and simpler to perform, taking only 2 hours, opposed to 5 days for BOD.
For consistent wastewater streams, a BOD:COD ratio can be calculated to reduce the frequency of BOD testing. This makes testing simpler, faster and cheaper. Untreated and filtered brewery wastewater typically has a BOD:COD ratio of 65%, whereas biologically treated wastewater will have a ratio between 10% and 30%.
3.4 What is pH?pH is a scale of measurement expressing the acidity or alkalinity of the wastewater. In the pH scale, a value below 7 shows that a wastewater is acidic, a value of 7 is neutral, and values higher than 7 are alkaline. The pH values are logarithmic, meaning a pH of 6 is 10 times more acidic than a pH of 7.
Biological treatment processes require neutral pH for the optimum growth of the treating biomass.
3.5 Why is pH regulated?Excessively acidic or alkaline wastewaters can cause substantial damage to sewer collection systems, lift stations and piping. Strongly acidic or alkaline wastewaters also pose a significant danger to any workers that service the sewer system. As such, governing bodies of these systems generally require the pH of wastewaters to be adjusted prior to discharge.
3.6 What is TSS?TSS stands for Total Suspended Solids and is the concentration of solid material present in a given wastewater stream.
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3.7 Why is TSS regulated?Suspended solids can accumulate in sewers and pump stations over time. This may cause blockages and failures of the equipment and system, disrupting services and increasing maintenance requirements. TSS also contains BOD. Additionally, increases in suspended solids loading at a wastewater treatment plant may increase the solids disposal costs charged to a brewery.
An interesting fact is that as cities become more efficient at water reuse and discharge less to the sewers, the sewers have less flow to move solids along, further compounding the problem of TSS!
3.7 What about Nitrogen and Phosphorus?There are numerous nitrogen containing compounds found in wastewaters. TN (Total Nitrogen) represents all nitrogen present in the wastewater, including organic and inorganic forms such as ammonia, nitrate, and nitrite. Wastewater discharge limits and surcharges may apply based on one or more types of nitrogen.
Phosphorus concentrations in wastewater are typically measured as either TP (total phosphorus) or OP (ortho-phosphate) and may also be subject to limits or surcharges. Both nitrogen and phosphorus contribute to eutrophication when released into natural waterways, and can impact operations and costs for local public wastewater treatment facilities. Discharge fees for nitrogen and phosphorus are not a concern for most breweries however, as these elements are rarely present at high levels in brewery wastewater.
3.9 Why is temperature important?High temperature wastewater (above 38°C) can negatively impact sewer systems by impacting on infrastructure, and posing a threat to sewer operator safety, or impacting downstream biological processes at the public wastewater treatment facility. Accordingly, local water authorities may have temperature requirements for wastewater discharged to sewer.
For secondary biological treatment processes, temperature impacts system sizing and choice of materials. Biological activity and efficiency increases with temperature in biological treatment such as BioGill, so control of temperature to optimize biological activity is a factor in system design and location.
Two BioGill Towers treating wastewater at a craft brewery located in New Hampshire, USA.
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Brewery wastewater typically has high COD and BOD due to the abundance of organic compounds such as sugars, soluble starches, ethanol, and organic acids. As the majority of the organic compounds are readily biodegradable, brewery wastewater can be very effectively treated biologically.
The pH of brewery effluent is largely determined by the use of CIP (clean in place) chemicals. However, the pH of non-CIP brewery wastewater will tend to
be acidic (pH of 4.5-6.5) under normal conditions due to presence of yeast. Without effective BOD removal, even pH adjusted wastewater will quickly drop in pH, due to the presence of fermenting organisms.
According to the Brewers Association Water and Wastewater: Treatment/volume Reduction Manual1 (USA), brewery wastewater assumptions are as follows:
PLEASE NOTE:
> Water consumed to beer produced ratio is typically 4-10L/L | 4-10gal/gal> For the new brewer, a ratio of 1:5.5 of beer to wastewater production can be used for estimating the volume of wastewater.> Solids screening or sedimentation can reduce BOD from between 10-40%, depending on the primary treatment steps utilized.
PARAMETER TYPICAL RANGE EXPECTED RANGE
BOD (mg/L) 600-5,000 1,200 – 3,6002
COD (mg/L) 1,800-6,000 1,800-5,500
TSS (mg/L) 200 – 1,500 200 - 1000
pH 3-12 4.5 -12
4. WHAT IS BREWERY WASTEWATER?8
BioGill is a secondary treatment technology used to reduce nutrient concentrations as part of an onsite brewery wastewater treatment solution. The BioGill above-ground bioreactors are quick to install and with low maintenance requirements, simple and cost effective to operate. As a result, brewers benefit from significant savings and control over wastewater discharge costs and improved environmental operations. Modular in design, a BioGill system can also be easily expanded as a brewery’s production increases.
At the technology’s core is patented nano-ceramic media known as “gills”, which provide an ideal environment for the attachment and growth of a healthy community of treating microorganisms (biomass). The scientifically designed gills are arranged in multiple, suspended vertical loops with wastewater dispersed across the top. One side of the gill is in contact with the high BOD brewery wastewater stream (“liquid side”), while the other is exposed to an abundant air supply and access to oxygen (“air side”), maximizing microbial growth and metabolic performance.
5. HOW BIOGILL TREATS BREWERY WASTEWATER
Basic configuration: BioGill Rapid with balance tank.
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The scientifically designed gills are arranged in multiple, suspended vertical loops with wastewater dispersed across the top. As the wastewater flows down the surface of the gills, microbes rapidly consume dissolved BOD. The metabolic activity of the biomass generates a convective air flow that moves upward along the air side between each set of loops. This provides oxygen to fuel growth and sustain the treating biomass, without the use of energy-intensive blowers or aerators.
All biological treatment processes create dead bacteria commonly referred to as “sludge”. Field tests have demonstrated that less sludge is
created by BioGill than conventional technologies. This sludge is much easier to settle and separate, if required, when compared to alternative technologies including MBBRs. Other advantages include lower energy and operating costs, odor reduction, and no difficult and messy draining of aerated basins for inspection and cleaning.
BioGill bioreactors offer efficient removal of soluble organic material in a compact, above-ground package. The robust and reliable performance of the BioGill technology can reduce soluble BOD in brewery wastewater by up to 99%.
KEY1. Inlet2. Dispersal Manifold3. Gills4. Air Vents/Natural Convection5. Outlet
Biofilm Biofilm
Looped GillLooped Gill
AirSide
AirSide
LiquidSide
Meet compliance & discharge limits
Resilient to shock loads & flow fluctuations
Save on surcharges
Compact footprint
BioGill bioreactor and gill structure
Simple to operate & maintain
Reduce odor Boost performance of
existing systems
BioGill Benefits
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5.1 BioGill Maintenance GuideTreating wastewater onsite shouldn’t be complex. A BioGill system for brewery wastewater treatment is designed to be as “hands-off” as possible, quick to install and simple to operate so you can get on with perfecting your latest brew. Unlike many alternative biological wastewater treatment technologies which have complex and sensitive operational requirements, BioGill systems do not require a full-time or highly trained wastewater operator.
The unique nature of the BioGill “gill” structure offers a highly robust and resilient biological system with fast startup and restart time, tolerance to fluctuations in loadings, and rapid biomass recovery in the event of unplanned shock load. Other biological treatment technologies may take weeks or months to regain the health of their biomass after accidental upset.
5.2 BioGiIl System Sizing GuideCompact and small in footprint, BioGill bioreactors are designed for space constrained locations or to add capacity to an existing treatment process.
BioGill offers three product options that can be combined to meet a range of treatment requirements: the BioGill Tower, the BioGill Rapid, and the BioGill Ultra.
BIOGILL TOWER BIOGILL RAPID BIOGILL ULTRA
Brewery Application:
1,000 to 10,000 bbl/yr
Brewery Application:
2,500 to 18,000 bbl/yr
Brewery Application:
16,000 to 60,000 bbl/yr
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Below is a general sizing guide, based on barrel production per year and expected wastewater volume. Note: Actual system sizing will depend on brewery specific wastewater volumes, loadings, and discharge/regulatory requirements. Please consult your authorized BioGill representative for site specific equipment sizing.
Brewery Treatment Guide (Cubic Meters per Day)
bbl of beer per year
Ultra
Rapid
Tower
Treatment Capacity (m3/day)
Bio
Gill
Pro
duct
0 6 12 18 24 30 36 42 48
10,0000 20,000 30,000 40,000
Brewery Treatment Guide (US Gallons per Day)
bbl of beer per year
Ultra
Rapid
Tower
Treatment Capacity (gpd)
Bio
Gill
Pro
duct
0 1,800 3,600 5,400 7,200 9,000 10,800 12,600 14,400
10,0000 20,000 30,000 40,000
1-6 Tower
1-6 Tower
1-6 Rapid
1-6 Rapid
1-3 Ultra
1-3 Ultra
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To help you get started, here are some helpful tips and hints on brewery wastewater treatment.
6.1 Floor drainsFloor drains are the first line of screening. A number of different manufacturers can provide industrial stainless steel drains suitable for breweries. Attention should be paid to the width of screening drains. Wider drains will provide more surface area to conduct the screening. It is preferable to keep as many solids out of the wastewater as possible. Drains need to stop larger particles (suggested size of 3mm or smaller) to stop bottle caps, gloves, labels, and or inorganic materials from entering the wastewater system.
6.2 Side StreamingOne of the best ways to minimize the capital and operating costs of an onsite wastewater treatment system is to employ side streaming best practices to segregate waste streams high in BOD and TSS such as spent grain, yeast, trub, and off-spec beer, before they enter the wastewater stream. Side streaming allows a brewer to significantly lower the strength of the brewery wastewater and hence surcharge fees. In addition, many of these brewery wastestreams can also have market value for use in feed stock or fertilizer.
The Brewers Association (USA) produced the “Wastewater Management Guidance Manual”. This is a great reference outlining several options for side streaming.
6.3 ScreensTypically, static screens are the best option for lower flow systems that cannot justify the expense of a more complex automated screen. Static screens can be highly effective, depending on the size and properties of the suspended solids. The simplest static screen is a basket strainer. A more effective static screen is a “waterfall or sidehill” wedgewire screen. Alternatively, the design can also include an automatic spray system to reduce maintenance. Often the sidehill static screens feature a parabolic design. This curve of the screen has several advantages with the dirt easily sliding down the screen as the wastewater passes through. The curved screen also facilitates simple maintenance with brushes used to collect solids in a bin or container below.
Internally-fed, rotary drum screens are an excellent option for screening brewery wastewaters. The rotary design allows for automatic operation, significantly reducing any maintenance requirements. The unit has a cylinder-shaped screen, which rotates when clogged with solids. Perforated drum screens are typically preferred over wedgewire designs. Air or water spray are often used to clean the collected solids off the cylinder, into a collection chute.
Both static and rotary screens can be selected with a range of perforation sizes. Typically, brewery wastewater will be screened at between 100 – 2,000 μm (micron). Smaller screen sizes will result in better solids removal but will require additional screen area and more frequent cleaning.
Your authorized BioGill representative can recommend the most suitable screen for your requirements and treatment processes.
6. TIPS & HINTS13
6.4 pH DosingpH correction can be as simple as taking a grab sample and manually adding acid or caustic However, this can be very time consuming.
Instead, pH dosing can be easily automated. There are two main ways to implement an automated pH correction system in a wastewater treatment plant.
i) In tank
A pH probe measures the pH of the wastewater directly in the balance tank. Acid and or caustic are dosed directly into the tank according to the pH set point of the system and current pH reading from the probe. One of the requirements of this type of system, is that the tank needs to be well mixed to ensure that the pH reading is indicative of the whole tank, and that added chemicals are sufficiently dispersed. This is achieved using industrial tank mixers/agitators or an aeration system.
Another consideration in this type of design is ensuring that the tank maintains a suitable minimum volume of wastewater. If the volume in the system is too small, the control action may over-correct the pH, and the system may start to oscillate between high and low pH, wasting significant amounts of chemicals.
pH probe placement is also important. The sensor should be below the minimum operating water level so that it would dry out, but above any sludge that will form in the bottom of the tank to avoid contact with significant solids. Incorrect pH probe placement may significantly increase the replacement frequency.
ii) External skid or panel
In these packaged skids or panels for pH correction, wastewater is pumped to the external system where the pH is measured, and acid or caustic are dosed accordingly. These systems are easy to install, operate and maintain. However, they do require an extra recirculation pump and there may be some issues with solids in this type of design.
6.5 Flow BalancingThe purpose of a balance (buffer) tank is to even-out influent flow so a consistent flow can be processed by the wastewater treatment system. The design of the balance tank largely focuses on the profile of the wastewater production. For instance, the majority of the wastewater may be produced in the afternoons or mornings, and production may not occur on the weekends.
A detail calculation can be performed to determine the optimal balance tank size. However, often in the case of smaller wastewater treatment systems, it is easier to simply select a volume that is 1.5 times (or greater) the maximum daily wastewater production.
It is also important that balance tanks are kept well mixed, so that significant variation in pH and concentration fluctuations are mitigated. Mixing can be achieved in a number of ways with two of the most effective being:
• Mechanical agitation• Coarse bubble aeration
Both methods can successfully mix a balance tank, and both provide some aeration of the influent wastewaters, helping to avoid anaerobic conditions. Your authorized BioGill representative can provide recommendations for sizing of mixers and aeration.
Managing your wastewater shouldn’t be costly or complex. If your brewery needs to save on surcharges, discharge fees and offsite hauling, we can help. A great place to start is investigating how much you are currently spending on wastewater management. Not sure what you’re paying now? No problem, you can even send us your water utility bills and we’ll do the calculations for you.
For further information, advice and guidance, please contact your authorized BioGill representative.
Disclaimer: As use conditions and applicable laws may differ from one brewery location to another and may change with time, the Customer is responsible for determining whether products and the information in this Guide are appropriate for the Customer’s use and for ensuring the Customer’s workplace and disposal practices are in compliance with applicable laws and other government enactments. BioGill Operations Pty Ltd, BioGill North American Inc. and all BioGill affiliates, assume no obligation or liability for the information in this Guide.
References:1. Brewers Association Water and Wastewater: Treatment/volume Reduction Manual2. The treatment of brewery wastewater for reuse: State of the art. Simate, G.S., Cluett, J., Iyuke,S.E., Musapatika, E.T., Ndlovu, S., Walubita, L.F. and Alvarez, A.E. 2, 2011, Desalination, Vol. 273, pp.235-247.
© BioGill Operations Pty Ltd October 2017. Patented technology. All rights reserved. BioGill Tower, BioGill Rapid & BioGill Ultra are trademarks of BioGill Operations Pty Ltd or one of its subsidiaries.
Case studies and technical reports are available at www.biogill.com
7. NEXT STEPS
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