Case Study: Modernization of Wastewater Treatment Facilities at the Decorative Printing (Poland)

The Case Study Describes Increasing of the Economic and Technological Treatment Efficiency of Wastewater Containing Dyes by Modernising the Wastewater Treatment Process Technology

SITE – Local wastewater treatment plant (WWTP) of the decorative printing plant
FLOWRATE – 25 m3/day
WW GENERATION SOURCES – Industrial wastewater from production machines and tank washing


The local wastewater treatment facilities of the decorative printing plant included stages of buffering, physical-chemical and biological treatment. The treated wastewater was discharged to the municipal sewer system. Despite the diligent operation of WWTP and high operating costs of chemicals, the treatment efficiency often did not meet the requirements for its discharge. For example, according to the municipal wastewater treatment plant discharge requirements, the maximum allowed concentration of the chemical oxygen demand (COD) should not exceed 1500 mg/l, when in fact it could reach 2000-3000 mg/l. Realising the need for increasing the WW treatment efficiency, the printing plant appealed to PRODEKO-EŁK Sp. z o.o., the part of the EKOTON Industrial Group, with a request to carry out an inspection of existing process technology and a corresponding WW treatment study to make a conclusion on the required modernisation of the WWTP.

Project implementation:

Upon the appeal, EKOTON technologists visited the plant’s treatment facilities, inspected the wastewater treatment site and took wastewater samples in order to conduct a detailed study on the efficiency of their possible treatment method. During the inspection and study, it was found that the existing wastewater treatment process does not correspond to the wastewater composition, and therefore the process technology should be changed. The technologists have proposed to use a flocculation process with dosing of aluminium coagulants with low chloride-ion content and polyacrylamide-based anionic flocculant (PAA). Such treatment allowed to remove a significant part of all contaminants which were in colloidal form, leaving dissolved organic matter in the filtrate, which could then be safely transferred to the next stage of biological treatment without harming the activity of microorganisms.

The designed treatment technology was tested several times in the laboratory and then repeated as an industrial-scale study. After the experimental approval of its high efficiency, the representatives of both companies proceeded to a technical discussion regarding the modernisation of the treatment facilities with possibility of saving the existing equipment. As a result of individual approach to the project, it was succeeded to found the optimal solution and to implement it with the lowest capital costs. Representatives of both companies worked side by side to launch and adjust the process. All additional customer requirements and demands were fulfilled to make the operation process as easy and convenient as possible.

Results and conclusions:

Owing to the carried out comprehensive study of existing treatment facilities and individual approach to the client, the optimal technological solution for the modernisation of the WWTP was found giving high treatment efficiency with minimal capital expenses. After launching and setting up the whole process, it was possible to achieve the quality requirements for the discharge into the municipal sewer system. The modernisation included simplification and operation automation of the entire technological process; operating costs reduction; improvement of the chemical dosing system and implementation of the intelligent dosing and flocculation technology; customisation and automation of the chamber filter-press and the whole dewatering process; increasing the flexibility of regulating and adjusting of the overall treatment processes.

Case Study: Municipal Wastewater Treatment Plant (Bridge City, TX, USA)



In the plant sludge drying beds for sludge dewatering were used. This method required lots of labor and constant maintenance. Due to this reason, the customer was looking for the efficient and minimal maintenance solution.


On-site pilot tests were carried out, using mobile dewatering unit MDQ-201, to find the best dewatering technology. According to the test results EKOTON offered sludge dewatering complex based on Multidisc Screw Press Dehydrator MDQ-354(2) CL. The complex includes – influent sludge feed pump, polymer feeder, three screw conveyors and service platform.

Type of sludgeaerobically digested excess sludge
Operating timeup to 8 h/day, 3 days/week
Unit sludge capacityup to 9 (18*) m3/h
up to 320 (400*) kg DS/h
Inlet sludge DS content3.5 %
Cake DS contentapprox. 22-23 %
Polymer consumption14.6 l/tonDS
TSS concentration in filtrate200 ppm
DS capture rate99.4 %
*in case of adding two additional dewatering drums.



Case Study: Municipal Wastewater Treatment Plant (Webster, Texas, USA)



The customer had an interest in reducing sludge disposal costs in their municipal wastewater treatment plant by obtaining lower maintenance costs and lower energy consumption. The plant treats wastewater from nearby residential areas and numerous local restaurants and generates about 120 gallons of aerobically digested sludge from their digesters per minute.


On-site pilot tests were carried out, using mobile dewatering unit MDQ-201, to find the best dewatering technology. According to the test results EKOTON offered sludge dewatering complex based on Multidisc Screw Press Dehydrator MDQ-354 C. The complex includes – macerator, polymer feeder and service platform.

Type of sludgeaerobically stabilized excess sludge
Operating time9-10 h/day, daily
Initial sludge capacity20 m3/h
310 kg DS/h
Inlet sludge DS content1.3-1.5 %
Cake DS content16-18 %
Polymer powder consumption8.8 g/kgDS
TSS concentration in filtrate70 ppm
DS capture rateup to 99.7 %



Case Study: Soapberry WWTP (Kingston, Jamaica)

START OF OPERATION – 2020 February


Soapberry WWTP located near Kingston Harbour has been operated since 2004. Biological wastewater treatment process is based on wetland lagoons. The WWTP has not previously had any sludge processing equipment, therefore since the start-up of the plant lagoons have been gradually filled with dry solid particles. As a result, sludge accumulation had impact on biological process efficiency, because of the reduced effective volume of the lagoons. For this reason, customer was looking for the solution to clean the bottom of the lagoons and process the sludge.


The lagoons cover an area of nearly 6 km2. Bottom sludge from the lagoons is removed by remote controlled dredger supplied by Dragflow. For this reason, EKOTON offered Mobile dewatering complex based on Multi-disc Screw Press Dehydrator MDQ-353 C. The complex includes mechanical screen, sludge tank, influent sludge feed pump, polymer solution preparation unit, polymer dosing pump, water tank, water pump and screw conveyors. All the equipment is mounted on the common platform. The complex can be fitted in a standard 40’ container or on a trailer, which allows an easy relocation.

Type of sludgebiologically digested lagoon sludge
Operating timeup to 23 h/day
Initial sludge capacity10-15 m3/h
Inlet sludge DS content2-3 %
Cake DS contentapprox. 23-26 %
Polymer powder consumption1-2 kg/tonDS
TSS concentration in filtrate100 ppm
DS capture ratemore than 99 %

Case Study: Municipal Wastewater Treatment Plant (Argentia, Newfoundland, Canada)

START OF OPERATION – 2019 November


The customer was looking for a low-cost, yet reliable and easy to operate solution for sewage from a construction site of an offshore platform treatment.


Project was carried together with our partner MABAREX. EKOTON offered Multi-disc Screw Press Dehydrator MDQ-102 C, which is the part of the containerized wastewater treatment plant.


Type of sludgeexcess activated sludge from MBR
Operating time6-10 h/d
Unit sludge supply0.5-1 m3/h
Inlet sludge ds content0.5-1 %
Cake DS content15-17 %
Polymer consumption5 kg/ton DS
TSS concentration in filtrate20-100 ppm
DS capture ratemore than 98 %

Case Study: KB Bioenergy, inc. (Akron, OH, USA)

TYPE OF INDUSTRY – Renewable energy


The customer was looking for a solution to replace one of the three existing centrifuges as well as to increase dry solid content, reduce energy consumption and improve operation.


On-site pilot tests were carried out, using mobile dewatering unit MDQ-201, to find the best dewatering technology. According to the test results EKOTON offered sludge dewatering technology based on Multi-disc Screw Press Dehydrator MDQ-354 CL together with service platform.


Type of sludgeanaerobically digested sludge
Operating time23 h/day, 6 days/week
Unit sludge supplyup to 78 gpm
up to 3,276 lbDS/h
Inlet sludge ds content8.4 %
Cake ds content26.5 %
Polymer consumption16.5 lb/ton DS
Tss concentration in filtrate350-500 ppm
Ds capture rateup to 99.4 %


Case Study: Guggisberg Cheese (Sugarcreek, OH, USA)

TYPE OF INDUSTRY – Dairy products
START OF OPERATION – 2018 December


The customer had an interest in reducing sludge disposal costs in their industrial wastewater treatment plant by obtaining lower maintenance costs and lower energy consumption. The plant treats industrial wastewater from a nearby cheese factory and generates about 15,000 gallons of activated sludge from their MBR system per day.


On-site pilot tests were carried out, using mobile dewatering unit MDQ-201, to find the best dewatering technology. According to the test results EKOTON offered sludge dewatering technology based on Multi-disc Screw
Press Dehydrator MDQ-353 C.


Type of sludgeaerobically stabilized MBR sludge
Operating time8 h/day, up to 5 days/week
Unit sludge supplyup to 12 m3/h
up to 230 kgDS/h
Inlet sludge ds content2%
Cake DS contentapprox. 18-20%
Polymer consumption4.0 g/kg DS
TSS concentration in filtrate50 ppm
DS capture rate99.7%



Case Study: Tannery Plant (Navarra, Spain)

EQUIPMENT Multi-Disc Screw Press Dehydrator MDQ-352C(1)
TYPE OF SLUDGE Tannery wastewater treatment process
DS LOAD 1200 kg DS/day


Sludge from the tannery production waste water treatment plant was filtered with use of a chamber
filter press. A large amount of lime used along with complex operation and low automatization level have
led to dissatisfaction and search for another dewatering technology. Additional aspect to consider was the future plans for the tannery plant capacity increasement, that the new dewatering solution should be able to deal with.


Aſter pilot tests, which were performed in January 2019, Multi-Disc Screw Press dewatering technology was selected for renovation. MDQ unit showed high productivity and dewatering efficiency at the same time with good quality of the filtrate.

A unique feature of MDQ is the ability to increase productivity by installation of additional screws. Taking into account future increasement in productivity, the MDQ-352C(1) with one screw and a free slot for the second one was offered to the Customer with perspective extension to MDQ 352. This has allowed the Customer to reduce initial CAPEX.

In July 2019 the new dewatering system based on Multi- Disc Screw Press Dehydrator MDQ-352C(1) has been commissioned under EKOTON expert’s supervision.


Current Unit's DS Productivity150-180 kg DS/h
Cake DS Concentration35 %
Operation Mode6-8 h/day
Average Polymer Dose4,5-7 kg/1000 kg DS
DS Capture Rate99,6-99,9 %

Case Study: Sludge Dewatering Complex for Automotive Manufacturer (Tychy, Poland)

CAPACITY OF SLUDGE 10 m3 per day, 7% DS
CUSTOMER Fenice Sp.z.o.o.


Complex mix of municipal and industrial waste waters, including wastes from paint and other various manufacturing sites aſt er sedimentation was dewatered using decanter centrifuge. High operational costs (cake removal, flocculant, electricity) lead to dissatisfaction and searching for other dewatering technology. Mobile out-door design of centrifuge also didn’t allow whole year operation that resulted in some discomfort.


Aſt er pilot tests made in 2017, the chamber fi lter press GK-8.230.20-H (fi lter area 230 m2, cake thickness 20 mm, plate dimensions 1500 x 1500 mm) with whole set of linked technological equipment: feeding pumps station, cloth regeneration station, operational platform was installed on site. All equipment was chosen, delivered and mounted by Ekoton. During August 2019 commissioning of dewatered site was made by Ekoton specialists. The fi lter press and linked equipment were mounted in the hall simultaneously with installation of cake removal system, that allows all-year operation. One of the most valuable preference of presented technology is possibility of sludge dewatering without any reagents adding.


Type of sludgeMix of municipal and industrial
waste waters with
wastes from paint site
Unit Productivity10 m3 per day
Feed Sludge DS Concentration7 – 8 %
Cake DS Concentration27 – 30%
Flocculant / Reagent Adding0
Filtration Pressure6 bar
Operation Time12 – 14 hours per day
Fenice, Poland

Case Study: Delivery and Start-Up of the Sludge Dewatering Complex based on Multidisc Screw Dehydrators in Poultry Slaughterhouse (Kutno, Poland)

PURCHASER Nijhuis Industries Central Europe Sp. z o.o.
OBJECT Meat factory, poultry slaughterhouse
SEDIMENT TYPE Excessive activated sludge, initial flotation sludge


Sludges coming from the treatment of wastewater from meat processing services show specific parameters for this type of industry. They contain increased fat amounts and generally understood animal protein, which in turn requires use of dedicated technology for dewatering of this type of industrial sludge.

The sewage treatment plant is located around 20 km from Kutno, in the Łódź province. The initial entering sewage is a mixture of industrial wastewater from the production lines and biological wastewater which is formed as a result of the daily work of the plant.

The main goal of the investment was the construction of the wastewater treatment plant at the newly built production factory and as part of that the supply and commissioning of two independent and fully automated sludge dewatering complexes.

Plant Capacity5 000 m3/day
Sewage TypeIndustrial/poultry
Sludge TypeFlotation + biological
Total Amount of Sludge228 m3/day
Average DS in Sludge5,6 %
Average Weight of Solid Sediments12 845 kg DS/day
Initial Amount85 m3/day
DS in Initial Sludge10 %
Weight of Solid Sediments8 544 kg DS/day
Initial Amount143 m3/Day
DS in Initial Sludge3 %
Weight of Solid Sediments4 300 kg DS/d
DS Content in Sludge Cake22%-26% +/-1%

Work Progress

To determine the efficiency of sludge dewatering, first laboratory tests were performed. Because the plant in which this technology meant to be implemented was still under construction, the tests were carried out in another plant, which had an identical production line and purification technology to the built one. When selecting the device, the experience of EKOTON PRODEKO-EŁK was used as a supplier of comprehensive solutions based on modern technologies.

The analysis of advantages and disadvantages of the use of various sludge dewatering devices at a given facility has led to the selection of the multidisc screw dehydrators (MDQs), whose main advantages are:

  • simple operation,
  • low energy, flocculant, water consumption,
  • very low noise,
  • the ability to work in automatic mode

The scope of delivery included two independent drainage lines. Each of them consisted of a multidisc screw press, an automatic polymer preparation station, a sludge feed pump and a polymer dosing pump.

Multidisc screw dewatering units and the other supplied devices work efficiently and reliably. The
operating parameters of the sludge treatment units in both lines enable them to obtain sludges with the
level of DS up to 34%. Equipped with full automation, it allows the user to optimalise the dewatering process and meakes the sludge management much easier.