MKR Know-how: Industrial Wastewater Treatment

Unlike municipal wastewater treatment, industrial wastewater is highly process-specific. Composition, contamination load, temperature, chemistry, oil content, solids content, salt concentration and target quality can vary significantly depending on the industry and application.

Typical tasks in industrial wastewater treatment include:

• separating water from contaminants
• reducing liquid residual streams
• recovering process water
• extending wash bath or media service life
• separating oils, greases, particles and emulsions
• concentrating wastewater for disposal
• preparing water for reuse, post-treatment or disposal

In short: industrial wastewater treatment makes it possible to treat contaminated process media in a technically reliable, economically efficient and environmentally responsible way.

Why Is Industrial Wastewater Treatment Becoming Increasingly Important?

Industrial water and wastewater streams are becoming a strategic issue for many companies. Rising disposal costs, increasing sustainability requirements, water scarcity, stricter regulations and the need for more stable processes are driving the demand for efficient treatment solutions.

This topic is particularly relevant for companies with:

• high wastewater volumes
• frequent bath changes
• oily or emulsion-containing media
• strongly fluctuating process water quality
• high disposal and operating costs
• requirements for process water recovery
• resource-efficiency or circular water management goals

A suitable treatment solution can help reduce wastewater volumes, keep process media usable for longer and retain water more effectively within the production process.

What Are the Goals of Industrial Wastewater Treatment?

The goals depend strongly on the medium, process and site-specific requirements. In many applications, several objectives are pursued at the same time.

Reducing Wastewater Volumes

Many industrial wastewater streams must be disposed of externally. Suitable technologies such as evaporation, ultrafiltration or pretreatment can reduce liquid residual streams and discharge concentrates in a controlled manner.

Recovering Process Water

Depending on the medium, target quality and process requirements, treated water can be reused or further treated. This can help reduce freshwater demand.

Reducing Operating Costs

Disposal, freshwater, chemicals, bath changes, system downtime and maintenance all create ongoing costs. A suitable treatment solution can significantly reduce these costs depending on the application.

Increasing Process Stability

Stable process media support consistent product quality. This is particularly important in industrial parts cleaning, metalworking, surface treatment and automotive processes.

Supporting Environmental and Sustainability Goals

Reduced wastewater volumes, longer media service life and improved water circulation help conserve resources and support environmental objectives.

Enabling Zero Liquid Discharge Concepts

In certain applications, industrial wastewater treatment can be part of a Zero Liquid Discharge concept. The aim is to reduce liquid residual streams as far as technically and economically feasible. The technical implementation always depends on the medium and the specific requirements.

What Types of Wastewater Are Generated in Industry?

Industrial wastewater varies greatly depending on the industry and process. That is why every technical design starts with an analysis of the medium and the treatment objective.

Washing and Degreasing Baths

Washing and degreasing baths are contaminated with oils, greases, particles, cooling lubricants and emulsions. Without continuous bath care, cleaning performance decreases and bath changes become more frequent.

Cooling Lubricants and Emulsions

In metalworking, media often contain oils, emulsions, chips, fine particles and chemical additives. The suitable treatment method depends strongly on the condition of the medium and the desired result.

Rinsing Water

Rinsing water is commonly generated in surface treatment, electroplating, paint pretreatment and chemical processes. It may contain dissolved substances, salts, metals or chemical residues.

Oily Wastewater

Oily wastewater is generated in production, maintenance, parts washing systems and metalworking. Depending on the form of the oil, tramp oil separators, ultrafiltration or evaporation may be used.

Wastewater from Surface Treatment

Surface treatment processes can generate complex wastewater containing chemicals, metals, salts or rinsing media. Evaporation technology, pretreatment, post-treatment or Zero Liquid Discharge concepts may be relevant here.

Concentrates and Residual Streams

Filtration, membrane processes and pretreatment steps often generate concentrates that must be further reduced, treated or disposed of. Evaporation technology can play an important role in this context.

Evaporation Technology

Evaporation technology thermally separates water from contaminants. Industrial wastewater is heated, water evaporates and is then condensed as distillate. What remains is a concentrate containing the retained substances.

Result of Evaporation

• Distillate: recovered water that can be reused, post-treated or discharged according to local requirements depending on its quality and the application.
• Concentrate: concentrated residual stream that is discharged in a controlled manner and then disposed of or further treated.

When Is Evaporation Technology Suitable?

Evaporation technology is particularly suitable when wastewater has a complex composition, disposal costs are high or liquid residual streams need to be significantly reduced.

Typical applications include:

• industrial wastewater from metalworking
• rinsing water and process water
• wastewater from surface treatment
• oily or chemically contaminated media
• concentrates from pretreatment processes
• Zero Liquid Discharge and circular water concepts

MKR Focus: Atmospheric Evaporation

MKR uses atmospheric evaporation technology without a vacuum system. In combination with mechanical vapor recompression, the energy contained in the vapor is recovered and reused in the process.

This supports energy-efficient operation and robust industrial application.

Learn more: Atmospheric evaporators from MKR

Mechanical Vapor Recompression / MVR

Mechanical vapor recompression, often referred to internationally as MVR, is a method for using the energy contained in the generated vapor.

During evaporation, water vapor is produced. This vapor is mechanically compressed. Compression increases its temperature. The heat is then returned to the evaporation process.

Advantages of MVR in Evaporation Technology

• recovery of thermal energy
• lower external energy demand
• efficient continuous operation
• suitable for industrial wastewater streams
• important basis for modern evaporation concepts

In short: MVR does not treat vapor as waste heat, but as an energy source within the process.

Ultrafiltration

Ultrafiltration is a membrane-based process for cleaning process media. In industrial parts cleaning, it is mainly used for the care of washing and degreasing baths.

The contaminated washing medium is passed over ceramic membranes. Contaminants such as oils, greases, particles and emulsions are retained. The cleaned medium can be returned to the process depending on the application.

Result of Ultrafiltration

• Permeate: cleaned medium that passes through the membrane.
• Retentate: concentrated contaminants that are retained and discharged.
   

When Is Ultrafiltration Suitable?

Ultrafiltration is particularly suitable when washing or degreasing baths need to be stabilized and kept usable for longer.

Typical applications include:

• industrial parts cleaning
• metalworking
• automotive production
• paint pretreatment
• degreasing baths
• washing baths
• media influenced by cooling lubricants

Advantages of Ultrafiltration

• longer wash bath service life
• fewer bath changes
• more stable cleaning quality
• lower disposal volumes
• reduction of oils, particles and emulsions
• continuous bath care during operation

Learn more: Ultrafiltration systems from MKR

Technical Data and Performance

* Higher values on request.

Tramp Oil Separation

Tramp oil separators are used to remove non-emulsified tramp oils from process media. They can be an important part of pretreatment, especially for washing media, cooling lubricants or oily wastewater.

When Is Tramp Oil Separation Suitable?

• when free oil is present on the surface
• to relieve downstream treatment processes
• to improve media quality
• as part of a modular treatment concept

Tramp oil separation does not always replace more advanced treatment, but it can improve process stability and support downstream technologies.

Mobile Media Care

Not every application immediately requires a stationary system. In many production areas, mobile solutions are useful for flexibly extracting, filtering or cleaning process media.

MKR mobile suction and filter units can be used directly at machines, tanks or systems.

Typical Tasks of Mobile Systems

• extracting process media
• filtering cooling lubricants, oils or washing media
• removing chips, sludge and particles
• cleaning machines and tanks
• supporting maintenance activities
• flexible media care at multiple operating points

Advantages of Mobile Solutions

• flexible use
• ready for quick deployment
• support for maintenance and production
• reduced manual media handling
• cleaner and safer process environment

Learn more: Mobile solutions from MKR

Zero Liquid Discharge

Zero Liquid Discharge, or ZLD, describes a treatment concept in which liquid residual streams are reduced as far as technically and economically feasible. The aim is to maximize water circulation and minimize liquid waste.

ZLD is not a single product. It is a process concept that may consist of several treatment steps:

• pretreatment
• filtration or ultrafiltration
• evaporation technology
• concentrate reduction
• post-treatment
• process water recovery

When Is ZLD Useful?

ZLD can be useful when companies want to significantly reduce wastewater volumes, recover water or minimize liquid residual streams.

Typical reasons include:

• high disposal costs
• limited discharge options
• sustainability goals
• water scarcity
• requirements for circular water management
• complex industrial media

The technical implementation must always be evaluated based on the medium, target quality, site requirements and economic feasibility.

Learn more: Zero Liquid Discharge with MKR

Modular Peripherals

Industrial wastewater treatment rarely works through one machine alone. In many cases, process stability depends on the interaction of pretreatment, the main treatment technology, post-treatment, tanks, pumps, filtration and control technology.

MKR offers modular peripheral solutions that can be electrically and mechanically integrated into new or existing system concepts.

Typical Peripheral Modules

• tanks and buffer vessels
• pump stations
• bag filters
• belt filters
• tramp oil separators
• dosing technology
• pH adjustment
• measurement, control and automation technology
• post-treatment
• storage and filling systems

Why Modular Peripherals Matter

• adaptation to medium and flow rate
• higher process reliability
• better integration into existing processes
• expandability when requirements change
• complete process solution instead of a single machine

In short: peripherals turn a system into a functioning process concept.

When Is Industrial Wastewater Treatment Economically Viable?

An industrial wastewater treatment system is particularly worthwhile when ongoing costs or technical problems arise from process media and wastewater.

Typical economic drivers include:

• high disposal costs
• frequent bath changes
• high freshwater costs
• downtime due to media changes
• fluctuating cleaning quality
• high chemical consumption
• increasing environmental or documentation requirements
• limited discharge options
• need for process water recovery

Economic feasibility always depends on the specific application. Important factors include medium, flow rate, contamination, operating time, disposal costs, target quality, energy demand and integration effort.

MKR evaluates these factors as part of a technical and economic assessment.

Why MKR?

MKR develops and manufactures systems for industrial water and wastewater treatment. The focus is on practical solutions for industrial process media, wastewater recycling and residual stream reduction.

What Sets MKR Apart

• experience in industrial wastewater and process water technology
• proprietary technologies for evaporation, ultrafiltration and mobile media care
• modular peripherals for complete process solutions
• technical design matched to the medium
• integration into existing production processes
• consulting from application analysis to service
• solutions made in Germany

MKR does not view industrial wastewater treatment in isolation, but as part of the entire production and media process.

Frequently Asked Questions about Industrial Wastewater Treatment

What is industrial wastewater treatment?

Industrial wastewater treatment includes technologies for treating, separating, concentrating or recovering contaminated liquids from industrial production processes. The aim is to reduce wastewater volumes, recover process water or prepare media for reuse, post-treatment or disposal.

Which technologies are used for industrial wastewater treatment?

Typical technologies include evaporation, ultrafiltration, tramp oil separation, filtration, chemical-physical pretreatment, post-treatment and Zero Liquid Discharge concepts. The suitable technology depends on the medium, contamination load, flow rate and target quality.

When is an evaporator suitable for industrial wastewater?

An evaporator is particularly suitable when complex industrial wastewater needs to be treated, liquid residual streams reduced or process water recovered. Technical suitability depends on composition, target quality and process conditions.

What is the difference between distillate and concentrate?

Distillate is the recovered water generated during evaporation. Concentrate is the remaining residual stream in which the retained substances are concentrated.

Can distillate be reused?

Depending on its quality, the application and process requirements, distillate can be reused or further treated. Suitability must be assessed for each application.

What is ultrafiltration?

Ultrafiltration is a membrane-based process that separates contaminants from liquids. In industrial parts cleaning, ultrafiltration is often used for the care of washing and degreasing baths.

How does ultrafiltration extend the service life of wash baths?

Ultrafiltration continuously removes oils, greases, particles and emulsions from the wash bath. This helps keep the medium stable for longer and reduces the need for bath changes.

What is the difference between permeate and retentate?

Permeate is the cleaned medium that passes through the membrane. Retentate contains the retained contaminants and is discharged as a concentrated stream.

What does Zero Liquid Discharge mean?

Zero Liquid Discharge describes a treatment concept in which liquid residual streams are reduced as far as technically and economically feasible. The aim is to maximize water circulation.

Is ZLD always completely wastewater-free?

ZLD must be evaluated for each application. Depending on the medium, process requirements and technical design, liquid residual streams can be significantly reduced. A completely wastewater-free solution is not technically or economically practical in every application.

What role does pretreatment play?

Pretreatment may be necessary to control oils, solids, particles, pH value or other interfering substances before the main treatment step. It improves process stability and protects downstream technologies.

What role does post-treatment play?

Post-treatment may be required when a defined water quality must be achieved for reuse, discharge or further process steps.

Can systems be integrated into existing processes?

Yes. Depending on the application, MKR systems can be integrated into existing production and wastewater processes. Tanks, pump stations, filters, control technology and other peripheral modules can be used.

Which industries use industrial wastewater treatment?

Typical industries include metalworking, automotive, surface treatment, paint pretreatment, heat treatment, chemical industry, disposal and recycling, aviation / MRO and other industrial production sectors.

When is an in-house wastewater treatment system worthwhile?

An in-house system can be useful when disposal costs are high, bath changes are frequent, wastewater volumes are large, freshwater costs are increasing or water recycling is required. Economic efficiency should always be assessed individually.

How does MKR evaluate the right solution?

MKR considers the medium, process, flow rate, target quality, operating times, disposal costs, integration effort and potential recovery benefits. This results in an application-specific system and process concept.

Can mobile media care replace a stationary system?

Mobile media care is suitable for flexible use at machines, tanks or production areas. It can supplement a stationary system or be an economical solution in certain applications. The decision depends on the use case.

Can different technologies be combined?

Yes. In many applications, combining several technologies is useful — for example ultrafiltration for bath care, evaporation technology for wastewater reduction and peripherals for media handling, pretreatment or post-treatment.

What is the first step toward a suitable solution?

The first step is to evaluate the medium and the treatment objective. This includes information on wastewater volume, composition, disposal costs, process requirements and the desired water quality.