The quantities of wastewater from the dairy industry are relatively limited and are directly related to the quantities of processed milk and dairy products. Such waters are very polluted and require the use of relatively complex systems for purification.

Origin and characteristics of technological wastewater in dairies
Most of the technological wastewater in the dairy industry is generated:

  • by cleaning of production equipment and tanks for milk transport
  • by leaking milk during production process
  • by leaking milk final products during the confectioning.

Cleaning of equipment is usually done in two phases. In the first phase, very strong alkali such as NaOH with pH 12-13 is used for washing, and in the second phase, strong acids (pH 2-3) are used. In order to improve the efficiency of cleaning and washing equipment, surfactants are added in both phases. Hence, the technological wastewater in dairies are diluted milk and water with detergent additives.

The type of substances in these technological wastewaters also depends on the origin, type and composition of milk. An average sample of cow's milk has the following composition:

  • pH: 4-6
  • Dry substances: 12-13%
  • Fat: 3-4%
  • Protein: 3.2-3.6%
  • HPK: 130 000-150 000 mg / l

These values are indicative because the composition of the milk varies depending on the place of breeding, the type of cow, the diet and the season.

 Quantities and quality of technological wastewater from the dairy

 (The provided data are indicative, and are needed and serve to understand the problem of treatment of this type of wastewater)

It is a known fact that technological wastewater generated in milk processing processes is very different from case to case, because almost every industry has its own specific production and technology, which affects the quantity and quality of wastewater. That is why it is very important to get well acquainted with the production process as well as periodically test and measure the flow, as well as to perform analyzes of wastewater quality on composite samples.

Based on our many years of experience in wastewater treatment, we can provide the following range of values of parameters that measure the degree of pollution of wastewater, and which are typical for technological wastewater in the dairy industry (daily samples):

  • pH: 3-12
  • HPK: 1338 -7500 mg / l
  • BOD5: 600-3400 mg / l
  • Fat: 50 -1500 mg / l
  • Total phosphorus: 15-35 mg / l
  • Total nitrogen: 50-100 mg / l

In general, lower pollution values apply to dairies that produce fresh milk and long life milk. The biggest pollution is caused by cheese production, whereby there is also the discharge of whey into technological waters. Whey, in addition to significantly polluting wastewater, has a very negative impact on all wastewater treatment technologies, so today it is recommended to separate it from the system and use it as an additional by-product (pig feed, etc.), or it can be used in biogas plants.


Taking into account all the above and the specifics of each case, we offer our clients:

  • Unique wastewater treatment technology which takes into account the specifics of each production
  • Preparation of project documentation, obtaining water permits and water acts: conducting procedures from location conditions, drafting projects, approvals, studies, environmental impact assessment studies, to water permits – “project management”
  • Testing of wastewater in the laboratory and at the "pilot" plant on site, in order to find and confirm the technological solution for which we guarantee treatment to the required limit values (ELV)
  • Application of the concept of circular economy
  • Production of equipment, installation, launching, proving of parameters for discharge to the recipient (ELV)
  • Supervision, monitoring, and maintenance of the wastewater treatment systems


Due to all the above, defining the technology and choosing the equipment needs to be done very carefully.

  •  Basic systems and equipment for wastewater treatment in the dairy industry:
  • Mechanical treatment in wastewater treatment technology includes equalization, separation of coarse material on grates and sieves, separation of inert, sedimentary and filterable particles, as well as separation of fats and oils.
  • Chemical pre-treatment (pH regulation, coagulation and flocculation)
  • Flotation with supersaturated air solution DAF DEVICE - (Dissolved Air Flotation) the device is used to separate dispersed and suspended particles from wastewater. The efficiency of this device enables us to significantly reduce the parameters (suspended matter, oils and fats, BOD5, HPK, etc.). Read more
  • Biological pretreatment
  • Treatment of flotation and biological sludge





DAF (Dissolved Air Flotation) device is used for separation of  dispersed and suspended particles from wastewater. Flotation is a mechanical separation proccess based on making supersaturated air solution in wastewater, meaning that micro bubbles make contact and connect with suspended substances and enable them to reach the surface and float.The air is being dispersed from the bottom of the pool, t it “collects” particles on it’s way up and pushes them to the surface. Coagulant neutralizes the electrostatic load of colloid particles and enables their agglomeration into floccules. Polyelectrolyte connects the neutralized particles into even bigger floccules. Piping saturator has a unique construction and enables air bubbles with dimensions 10-70 micrometers, what provides an extraordinary efficiency. AREAS OF APPLICATION AND MAIN APPLICATIONS Milk industry, ice cream production, juice production, alcoholic beverages production, breweries, fish and meat processing, fruit and vegetables processing, drinking water, etc. Plastic recycling, chemical industry, oil and gas, textile industry, leather industry, laundry services, package washing etc. Advantages of our DAF Systems: - Very high level of reduction of pollution parameters Suspended substances Reduction rate from 90-99% Oils and fats Reduction rate trom 90-99% BPK5 Reduction rate from 70=80% HPK Reducstion rate from 70-80% - Comprehensive and efficient solution which provides high stability and efficient removing of dirt. Reliable method for refining of technological wastewater. - Simple installations provide compact equipment set and saves space. - Major savings because the system construction and technological parameters ensure small consumption of energy, air and chemicals. - Very stable functioning of coagulation, neutralization and flocculation systems. - Law level of turbulences, there is no re-retraction of floating sediments. - We have available a developed digital services package which provides follow-up and optimization of the DAF system long-distance working and remote controllie of thesystems. - Instead of classical lamellas, we use special “U” profiles which provide: Separated flowi of wastewater and clean water Equal distribution of wastewater flow and sectors load, decreasing the turbulence There is no obstruction of flow of flotants Flow leaders secure less consumption of polymers DAF is a device made of stainless steel We can deliver complete systems or rebuild and upgrade existing DAF devices.


Read more


Type of wastewater: technological wastewater from battery production and recycling Capacity: 700 m³/day, 29 m³/h Table 1: Types of wastewaters and damaging and dangerous substances generated during the production process Types of wastewater Origin Existing hazardous and dangerous matters Alkaline rinsing water Workspace and streets cleaning Lead and dust Sour rinsing water with high concentration Paste mixer and shepherd machine washing Pb, PbO2, PbSO4 Neutral concentrates Wet Ventures - scrubbers Pb, Sn, Sb, hydroxides Water from battery formulation Charging battery with acid Sulfuric acid Water from battery recycling Cutting and emptying of battery Sulfuric acid, Pb, PbO2, PbSO4 Outgoing water quality Purified wastewater from the treatment plant should satisfy the following limit values for discharing into the land waters (in this case a small river). Limit values are extremely low for some hard metals, which are contained in these wastewaters, such as: Cadmium – 0,1 mg/l Lead – 0,5 mg/l Iron – 2 mg/l Sulfates – 250 mg/l Suspended substances – 35 mg/l BPK5 – 25 mg/l HPK – 125 mg/l, etc.   The investor’s request was to deliver a technological solution – Technology for wastewater processing through the project: machine, electro and measuring regulating equipment, electro-commanding cabinet with PLC and software, launching and a guarantee that the required parameters will be inside the limit values. Plant working regime: Continually (moze I : non-stop), 24h/7 daysOV generated during he production process are being treated trough three lines: Water line Dirt line Preparation and chemicals dosing line These technologies are being established on the water line: Egalisation Neutralisation Neutralisation II and removing of sulfates Coagulation Flocculation Sedimentation Clarification of sedimented water Final control These technologies are being established on the preparation and chemicals dosing line: Preparing a dosing solution Dosing the solution   The system is completely automatized, with support of electro- commanding cabinet with SIEMENS PLC, software and measuring regulation equipment. After the equipment is delivered and the system is launched, chemical analysis of the purified OV have been done in an accredited lab. Those analysis showed that all parameters were inside the limit values.  


Read more


Filter plates at Mebrane filter press are equipped with membranes that enable additional "squeezing" -dehydration of the filter cake. Increasing the filling pressure ensures precompression and drainage of the filter cake in the chamber. When the filling pressure reaches a predetermined value (approximately 6-8 bar), the filter cake is additionally exposed to the membrane pressure, and additionally "squeezed". Elastic membranes, which can be made of polypropylene (PP) and synthetic rubber (NBR, EPDM), use compressed air to press the filter cake over the entire surface of the chambers. Additional compression thus expels free water through the filter cloth. ADVANTAGES OF MEMBRANE FILTER PRESSES: •  More economical filtration due to high degree of drainage and shorter cycle time  Maximum flexibility for expansion and automation possibilities  Extended pump life in the case of abrasive media, due to low supply pressure CASE STUDY:  Delivery of membrane filter press with the dimensions of plates 1000x 1000 mm, 36 plates, volume 770 liters, for filtering the solution of lead "paste" in the process of battery recycling. Investor "TAB MAK".  The press is equipped with: membrane plates with EPDM membrane, system for automatic opening of plates, "Squezing" system for additional dehydration of filter cakes, "drip tray" system. Degree of dehydration of filter cakes: 80-90% dry matter..  


Read more