Beverage production involves a variety of processes such as mixing, bottling, cleaning and cooling, all of which use water in different qualities and quantities. As a result, industrial wastewater is produced, which can vary greatly in terms of quantity and composition. The treatment of this wastewater is essential in order to comply with legal requirements, optimize operating costs and minimize environmental impact. This article describes in detail the specific properties of wastewater in the beverage industry, the technological challenges and the practical methods of treatment.
Table of contents
Composition of wastewater in beverage production
Waste water from beverage production usually contains a complex mixture of organic and inorganic substances. Typical ingredients are
Organic loads:
- Sugar, starch and other carbohydrates from the production of soft drinks, juices and alcoholic beverages.
- Residues from fermentation, especially in beer and wine production, such as ethanol, methanol and yeast cells.
- Fats, oils and proteins from the processing of dairy products in dairies that produce drinks such as shakes or lassis.
Inorganic impurities:
- Residues of cleaning agents such as alkalis and acids that are used for CIP (Cleaning-In-Place) cleaning of pipes, tanks and filling systems.
- Salts and minerals from softened or conditioned process water.
Solids:
- Sediments from filtration or pressing residues from fruit juices.
- Suspended solids and organic solids from residues in raw materials.
Specific loads:
- High pH value fluctuations due to the change between alkaline and acidic cleaning agents.
- Substances that are not readily biodegradable, such as certain preservatives or additives.
Technical challenges
The treatment of wastewater from beverage production requires an adapted strategy, as the loads depend heavily on the product range, the production technology and the cleaning processes used. Typical challenges are
High COD value (chemical oxygen demand):
- Organic substances lead to a high COD, which makes biological or chemical treatment necessary.
Fluctuating wastewater volumes:
- Seasonal production or different batch sizes can lead to widely varying wastewater volumes, which requires flexible treatment capacities.
Foam formation:
- Sugar and surfactants can cause foaming and disturbances in biological clarification processes.
Corrosion and fouling risks:
- Cleaning agent residues can attack system materials and pollute membrane systems.
Treatment procedure
The choice of treatment process depends on the composition of the wastewater and the legally prescribed discharge parameters. A combination of mechanical, chemical-physical and biological processes has proven to be suitable in practice.
1. mechanical pre-treatment
- Rakes and sieves: Removal of solids such as fruit pieces or label residues.
- Filtration systems: Separation of heavy particles, e.g. glass particles or sediments.
- Sedimentation: Pre-separation of suspended solids to relieve downstream processes.
Photo: Our ALMA FIL multi-layer filters with downstream ALMA ION ion exchanger
2. chemical-physical treatment
The chemical-physical treatment of wastewater combines chemical reactions and physical separation processes to effectively remove dissolved, colloidal and finely suspended substances. It often forms a central part of the pre- or intermediate treatment of wastewater and optimally prepares the water for subsequent biological or mechanical processes. Here are the main methods in detail:
Precipitation and flocculation
Precipitation and flocculation are proven processes for removing colloidal and finely dispersed substances that cannot be separated in a purely mechanical treatment.
Precipitation: During precipitation, chemical precipitants such as aluminum sulfate, iron (III) chloride or polyaluminum chloride are added to the wastewater. These cause a chemical transformation of the substances dissolved in the water, resulting in insoluble compounds. These newly formed particles are often microscopically small and cannot be separated without additional measures.
Flocculation: Flocculants (e.g. polymers) are used to combine the particles formed during precipitation into larger, more easily separable agglomerates. These promote the formation of larger flocs, which can be efficiently separated by physical processes such as sedimentation or flotation.
This process is particularly important when treating wastewater that contains high concentrations of organic or inorganic colloidal substances, as is often the case in beverage production. Precise dosing and selection of chemicals is crucial to achieve optimal results.
Neutralization
Neutralization is used to balance out pH fluctuations that can be caused by production processes or the use of cleaning chemicals. Acids or alkalis are dosed to bring the pH value of the wastewater into the neutral range (pH 6.5-8.5), which is crucial for subsequent treatment processes.
- Praktische Durchführung: Bei stark alkalischem Abwasser (pH > 9) wird beispielsweise Schwefelsäure oder Kohlendioxid (CO₂) eingesetzt, während bei stark saurem Abwasser (pH < 6) häufig Natronlauge oder Kalkmilch zur Neutralisation verwendet werden. Moderne Anlagen verfügen über pH-Regelkreise, die die Chemikalienzufuhr automatisieren und präzise an den aktuellen Bedarf anpassen.
Correct neutralization protects downstream systems from corrosion or malfunctions and ensures compliance with legal discharge limits.
Dissolved Air Flotation (DAF)
DAF, or dissolved air flotation, is a physical process that was specially developed for the separation of fats, oils and proteins. These substances pose a particular challenge as they are often present on the water surface or as emulsions that are difficult to separate.
How it works: In DAF, pressurized water saturated with air is fed into the wastewater. By releasing the pressure, microscopically small air bubbles are formed which attach themselves to particles or flocs and transport them to the water surface. The separated substances can then be skimmed off as foam.
Practical application: Systems such as ALMA NeoDAF from ALMAWATECH combine state-of-the-art flotation technology with precise control to ensure high separation efficiencies and minimal use of chemicals.
Photo: Our CP system with neutralization and activated carbon filtration for the pre-treatment of wastewater containing heavy metals prior to reverse osmosis
3. biological treatment
Biological treatment uses microorganisms to break down organic impurities in wastewater. It is an essential part of wastewater treatment, especially for wastewater with a high chemical and biological oxygen demand (COD and BOD). Depending on the type of wastewater and the objective, aerobic and anaerobic processes as well as hybrid approaches such as biofiltration are used.
Aerobic process
Aerobic processes are based on the microbial decomposition of organic substances in the presence of oxygen. Microorganisms, such as bacteria and fungi, oxidize organic compounds to carbon dioxide (CO₂) and water.
Activated sludge process: This process is used in systems such as the ALMA BHU Bio. The wastewater is fed into an aerated reactor in which microorganisms are kept in suspension as activated sludge. A continuous supply of oxygen and mixing ensures efficient biological activity.
Advantages: Aerobic processes are particularly suitable for the treatment of easily degradable organic substances such as sugar or starch. They are able to achieve a high COD reduction and produce a stable excess sludge.
Anaerobic processes
Anaerobic processes take place without oxygen and are ideal for wastewater with a high organic load. They use special microorganisms that convert organic substances into biogas (methane and carbon dioxide).
Biogas reactors: Plants such as the ALMA BHU GMR use this process to convert organic substances into methane. The resulting biogas can be used to generate energy, e.g. steam or electricity.
Advantages: Anaerobic processes not only offer efficient wastewater treatment, but also help to reduce operating costs by generating energy. In addition, less sludge is produced than with aerobic processes.
Biofiltration
Biofiltration combines biological and mechanical processes to remove residual organic matter.
- How it works: In bioactive filters such as ALMA BHU BioFil, microorganisms adhere to a carrier material. The wastewater flows through the filter, whereby the microorganisms break down organic residues.
- Advantages: This technology is ideal for the post-treatment of wastewater and preparation for downstream membrane processes. It reduces biofouling and thus enables the economical operation of reverse osmosis systems.
Photo: Our biofiltration for the pre-treatment of organically contaminated wastewater upstream of a reverse osmosis system
4. post-treatment and water recycling
Post-treatment is used to remove any remaining trace substances and to treat wastewater for possible reuse as process water.
Reverse osmosis (RO)
Reverse osmosis is a membrane-based separation process that works under high pressure. It removes dissolved salts, organic molecules and other impurities.
- Application: The purified water can be reused as process water or for boiler feed. RO systems ensure that even the strictest water quality requirements are met.
Activated carbon filtration
Activated carbon filtration is used to remove organic trace substances, odors and flavors. It is also used to reduce chlorine, which can damage membranes and microorganisms.
Disinfection
Finally, the water is disinfected to minimize microbiological contamination. Systems such as ALMA OXI UV use UV light or ozone to efficiently kill bacteria, viruses and other microorganisms. This guarantees hygienic water quality and prevents recontamination in the circulation system.
Photo: Our reverse osmosis system for in-house water recycling
Conclusion
Wastewater treatment in beverage production requires customized solutions that are flexibly adapted to the specific loads and requirements of production. By using modern technologies such as biofiltration, membrane processes and biogas plants, ecological and economic goals can be achieved in equal measure.
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