Case Study – Dairy Processing Plant (Pennsylvania, USA)

CAPACITY OF WWTP up to 26,5 m3/day
END USER / CUSTOMER – Dairy Processing Plant (Pennsylvania, USA)

At Esmil, we excel at providing tailored solutions that address even the most unique industrial challenges. Our recent success story in Pennsylvania demonstrates our commitment to efficiency, cost savings, and environmental responsibility.

The Challenge:

A processing/industrial facility in Pennsylvania faced a daunting task – dewatering up to 26.5 m3/d of dairy sludge, starting with an initial dry solids content ranging between 3 and 3.5%. Their primary goal was to elevate the dry cake solids to above 15%, significantly reducing the expenses associated with haul out.

Our Innovative Solution:

Esmil stepped in with an approach that perfectly matched the plant’s requirements:

  • 2-Drum Multi-Disc Screw Press MDQ-202CD: With relatively light processing needs, we specified the MDQ-202CD, a compact yet high-performance dewatering solution.
  • Enclosed Shaftless Screw Conveyor: As part of our comprehensive solution, we included our enclosed shaftless screw conveyor, ensuring smooth and efficient transport of dewatered sludge.

Dehydrator MDQ

Minimizing Polymer Consumption:

Our solution not only achieved the desired dry cake solids content but also kept polymer consumption to a minimum. Esmil’s MDQ dewatering technology empowers operators to optimize polymer dosing during setup.  Operators can control the polymer dosing process. They can visually monitor the flocculation tank and adjust polymer dosing in real time. The operator interface terminal (OIT)T allows for precise adjustments to achieve optimal flocculation. Operators can fine-tune the polymer dose until the perfect flocculation point is reached, ensuring maximum efficiency.

The Outstanding Result:

Esmil’s solution not only met but exceeded the customer’s expectations:

  • Achieving High Cake Solids: The MDQ-202CD system successfully increased the dry cake solids to above 20%, dramatically reducing haul-out expenses.
  • Cost Efficiency: Minimizing polymer consumption was achieved without compromising performance, ensuring cost savings and environmental responsibility.
  • Customer Satisfaction: The customer was completely satisfied with our solution, which was installed in March 2023.

Dehydrator MDQ

Case Study: Modernization of the sludge dewatering complex (Trzcianka, Poland)

CUSTOMER – Municipal Construction Department in Trzcianka
OBJECT – Municipal wastewater treatment plant in Trzcianka
MDQ 452-С
October 2022


The wastewater treatment facilities in Trzcianka were built in the 1980s and had a capacity of 2,400 m³/day. The wastewater treatment used the active sludge method, in which the sludge was sent to stabilization chambers and then to sludge clarifiers. The treated wastewater was discharged through a drainage ditch to the Trzcinica River. In 2006-2007, wastewater treatment facilities were modernized and expanded to include both the biological and sludge treatment stages. As a result of these measures, the capacity of wastewater treatment facilities increased to 4000 m³/day. The volume of wastewater received during the year is currently approximately 700,000 m³.

In 2022 Municipal Construction Department in Trzcianka invested significantly in the modernization of both the water supply and sewerage systems and the wastewater treatment facilities themselves. One of them was the modernization of the sludge treatment stage.

The sludge treatment technology at the Trzcianka wastewater treatment facility includes anaerobic stabilization of excess sludge in two separate fermentation chambers (WKF), followed by dewatering and hygienization with lime for agricultural use. Before the modernization, sludge from the WKF chambers with a dry matter content of 1.5-2.5% was sent to the belt filter press, and as a result of dewatering, it was possible to achieve approximately 16% DM in the dewatered sludge.

Due to rising energy prices, the frequency of equipment breakdowns and the high cost of transporting dewatered sludge, the company’s management decided to replace the equipment in the sludge dewatering building with more efficient and cost-effective equipment that provides an automated dewatering process. In search of an optimal solution, the Municipal Construction Department of Trzcianka ordered pilot tests in real conditions on a full-size Esmil MDQ-201 Multi-Disc Screw Dehydrator from PRODEKO-EŁK Sp. z o. o., which is part of the Esmil Group. The tests were positive and promising, and the dewatering technology based on Esmil MDQ Dehydrators convinced the management. In July 2022, a tender was held for the supply, installation and start-up of the Sludge Dewatering Complex based on a Screw Press, which was won by PRODEKO-EŁK, meeting all the Customer’s requirements.



As part of the modernization, PRODEKO-EŁK Sp. z o. o., a part of the international ESMIL group, supplied, installed and started up the Sludge Dewatering Complex in the autumn of 2022, which included the following equipment:

  • Mutli-Disc Screw Press Esmil MDQ-452 C
  • Horizontal Screw Conveyor approximately 2 m long
  • Inclined Screw Conveyor with a length of approx. 6 m, which partially extends outside the building
  • Pump for sludge feeding + flow meter
  • Polymer inlet pump + flow meter
  • Polymer make-down unit
  • Macerator pump
  • Control cabinet of the entire complex with a touch panel

Esmil PRODEKO-EŁK also carried out a comprehensive supply of pipelines and cables for the complex, as well as mechanical and electrical installation of the devices. After the complex start-up and adjusting the equipment’s
operating parameters, the treatment facility operators rated all the advantages of process automation and technology that requires virtually no operator intervention, especially compared to the previously used belt filter press. In addition, the absence of wearing parts, lower operating costs (electricity, washing water, etc.) and a much higher degree of dewatering result in significant savings. It is worth noting that despite the larger amount of sludge processed per day, the overall polymer consumption per month is comparable. The previously used belt press allowed for the processing of approximately 1,300 m3 of sludge per month on average, while the multi-disc screw press MDQ-452 C enabled the processing of approximately 1,700 m3 of sludge per month on average. In both cases, the monthly consumption of the flocculant in the form of an emulsion is approx. 1 m3. A detailed comparison of the operating parameters of both equipment is presented in Table 1.

Table 1: Comparison of the previous belt filter press and the Multi-Disc Screw Dehydrator Esmil MDQ-452 C

Belt Filter Press

Multi-Disc Screw Dehydrator Esmil MDQ-452 C

DM content in the incoming sludge
1,5 – 2,5 %

Hydraulic flow capacity
~ 6,5 – 8 m3/h

8 – 15 m3/h
Dewatering performance
~ 97,5 – 200 kg DM/h

120 – 375 kg DM/h

DM content in dewatered sludge
~ 16 %

18 – 22 %

Reduction of sludge volume
6-10 times

9-14 times

Polymer dosage
15-19 kg/t DM
12-15 kg/t DM
Amount of polymer used in emulsion form per 1 m3 of sludge
≈ 0,8 l
≈ 0,6 l
Sludge processing per month
1200 - 1400 m3
1700 - 1800 m3
Electricity consumption
8,7 kW

4,2 kW

Washing water consumption

10 m3/h

0,2 m3/h

The advantages of using the Sludge Dewatering Complex based on Esmil Multi-Disc Screw Press MDQ:

  • better sludge dewatering, due to the reduced volume of sludge, which means less storage space is required and transportation costs are reduced;
  • more dewatered sludge per day;
  • less use of polymer, washing water and electricity;
  • no parts that wear out quickly;
  • does not require maintenance;
  • automated process.

sludge dewatering complex

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 Esmil 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 Esmil 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, Esmil 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. Esmil 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 Esmil 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 Esmil 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 Esmil 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: 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 Type Flotation + 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 Esmil 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.

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