Case Study: Success Story – A Year of Seamless Operation at the Ohio Biogas Plant, USA

At ESMIL, we’re dedicated to delivering innovative solutions that redefine efficiency and reliability in wastewater management. We’re thrilled to share our success story from a Biogas Plant in Ohio where our MDQ Multi-disc Screw Press has been operating for a year. This achievement speaks volumes about the transformative impact our technology can have on your operations.

The Challenge:

The Biogas Plant in Ohio faced several challenges with their previous dewatering equipment, an old centrifuge:

  • Frequent Failures: The old centrifuge failed too often, resulting in costly repairs and extensive downtime.
  • High Labor and Engineering Costs: Operating and maintaining the centrifuge required significant operator and engineering labor, increasing operational costs.
  • Performance Optimization: The plant needed to achieve high capacity, maintain high dry solids content in the cake, attain a high capture rate with low filtrate TSS, and minimize polymer consumption.
  • Variable Sludge Properties: The continuously changing sludge properties posed a challenge in maintaining a stable dewatering process.
  • Filtrate Reuse: There was a desire to reuse part of the filtrate for polymer solution preparation to reduce freshwater consumption.

Our Solution:

ESMIL provided a comprehensive solution tailored to the plant’s unique needs:

  • MDQ-454C Multi-disc Screw Press: Our state-of-the-art, 4-drum, MDQ system, designed for high-performance dewatering, offered the ideal solution.
  • Filtrate Reuse Feature: We incorporated a filtrate reuse feature, optimizing resource utilization.
  • Polymer Solution Preparation System: An advanced polymer solution preparation system ensures precise dosing and efficiency.
  • Dynamic and Static Mixers: Our polymer injection system featured both dynamic and static mixers for thorough polymer blending.
  • Comprehensive Control System: A fully integrated control system manages the entire dewatering complex, ensuring seamless operation.

The Achievements:

The results speak volumes about the success of our solution:

  • MDQ Design Capacity: 2450 lbsDS/h, 60 gpm.
  • MDQ Nominal Capacity: 2950 lbsDS/h, 90 gpm.
  • Cake Dry Solids: 26 – 32%.
  • Filtrate TSS: 700 – 1200 ppm.
  • Minimal Operator Intervention: The MDQ requires minimal operator time, reducing labor costs.
  • Stability: Our MDQ system operates stably even with continuously changing sludge properties.
  • Reduced Water Consumption: Freshwater consumption decreased significantly due to the use of about 30% filtrate for polymer solution dilution.

MDQ-454C Multi-disc Screw Press


ESMIL MDQ Multi-disc Screw Press is the ultimate solution for Biogas Plants seeking efficiency and reliability:

  • High Reliability: Say goodbye to frequent equipment failures and costly repairs.
  • Clean Filtrate: Our system delivers clean filtrate, crucial for further filtrate disposal steps.
  • High Dewatering Performance: Achieve remarkable results with high dry solids content in the cake.
  • Quiet and Vibration-Free: Enjoy a noise-free and vibration-free operation.
  • Ease of Operation: Our systems are designed for hassle-free operation.

Don’t let dewatering challenges hold your operations back. Join the ranks of satisfied customers who have experienced the ESMIL advantage. Contact us today to explore how our MDQ Multi-disc Screw Press can revolutionize your wastewater management. Efficiency is not a goal; it’s a guarantee with ESMIL.

Case Study: Unlocking Efficiency in Wastewater Management – Esmil’s Dewatering Expertise – Indiana, USA

Case Study: Western Hancock Utilities, Indiana

At Esmil, we pride ourselves on delivering cutting-edge solutions for the most challenging wastewater treatment scenarios. We are pleased to share our success story with Western Hancock Utilities in Indiana, where our expertise in dewatering waste-activated sludge (WAS) made a significant impact on operational efficiency.


Western Hancock Utilities faced the pressing challenge of efficiently dewatering WAS from their oxidation ditch at the wastewater treatment plant. Achieving optimal dewatering results and minimizing polymer consumption were key objectives. The system was sized to handle up to 185 GPM at 1.5% initial DS content waste-activated sludge. The minimum cake DS requirement was 18%.

Multi-disc Screw Press MDQ


Esmil stepped up to the challenge by offering an on-site pilot test, which allowed us to gather solid data points and identify the most efficient polymer and polymer consumption levels. Our commitment to precision and excellence shone through in every aspect of the project

1 – Pilot Test Success: Our pilot test yielded stellar results, demonstrating our ability to achieve the desired levels of dewatering efficiency and dry solids concentration.2 –
2 – Comprehensive Dewatering Package: Esmil provided Western Hancock Utilities with a comprehensive dewatering solution, including:

  • Esmil multi-disc dewatering press with advanced controls.
  • A polymer feeder for precise chemical dosing.
  • A sludge pump equipped with a flow meter for accurate monitoring.
  • Two Esmil shaftless screw conveyors to efficiently transport dry cake away from the press discharge to a designated dumpster.

3 – Smooth Start-Up: Our team ensured a seamless and successful start-up of the dewatering system, all completed within the designated timeframe in July 2023.


Thanks to Esmil’s expertise and state-of-the-art dewatering technology, Western Hancock Utilities achieved all that they required and more at their wastewater treatment plant. Our commitment to data-driven solutions allowed us to optimize polymer consumption, minimizing operational costs while maximizing performance.

Multi-disc Screw Press MDQ

Choose Esmil for Your Dewatering Needs:

This success story with Western Hancock Utilities is just one example of our dedication to delivering exceptional results. When you partner with Esmil, you benefit from:

  • Innovative solutions tailored to your specific challenges.
  • A commitment to data-driven decision-making for efficiency and cost-effectiveness.
  • Reliable and professional project execution, from pilot tests to start-up.

Esmil is your trusted partner in wastewater management, providing cutting-edge solutions that make a measurable impact on your operations. Contact us today to learn how we can help you optimize your wastewater treatment processes and achieve remarkable results.

Case Study: Catenary Screen (Brodnica, Poland)

PROJECT – Modernization of the Central Pumping Station in Brodnica, Poland
CUSTOMER – Municipal Water Supply and Sewerage Company Ltd. in Brodnica, Poland
OBJECT – Central Pumping Station at Piaski Street in Brodnica
COMMISSIONING – January – March 2023

Modernization plans and objectives 

According to the modernization plan for the Central Pumping Station on Piaski Street in Brodnica, the purpose was to replace the existing worn-out mechanical screens with bar screens and to increase the efficiency of solids removal from incoming wastewater. The entire modernization of the facility has been divided into the following stages: 

  • Stage No. I – January 2023 – delivery and installation of the first catenary screen KR 1322 with a clearance of 8 mm for wastewater channel No. 1
  • Stage No. II – March 2023 – delivery and installation of the second catenary screen KR 1322 with 8 mm clearance for wastewater channel No. 2
  • Stage No. III – planned – delivery and installation of a screw compacting press to reduce the amount and degree of moisture of the generated debris.

Situation before modernization

The city’s wastewater flows through one main sewer, which is divided into two identical channels, each with a width of 1240 mm and a depth of 2100 mm.

Prior to the replacement of the equipment at the pumping station, there were quite frequent problems caused by the failure of already depleted mechanical screens. In addition, the solid debris collected by the screens that were dumped on the trailer contained a large amount of water.

The main problems encountered so far by the pumping station staff included:

  • problems associated with a quite high failure rate of the depleted screens
  • high costs associated with repairing and maintaining the screens in continuous operation
  • the need for constant supervision and response to problems related to the ongoing operation of the pumping station.


After discussions with the Customer and after analyzing the situation of working conditions at the pumping station on Piaski Street in Brodnica, ESMIL PRODEKO-EŁK specialists decided to select for this project two catenary mechanical screens KR 1322 with a clearance of 8 mm with an average throughput of Qavg=1300 m3/h each. 

Screens Esmil

Installation of the new equipment allowed to obtain the following results:

  • the amount of removed screenings has increased significantly due to the use of a screen with a clearance of 8 mm;
  • the special design of the chain made it possible to more effectively collect and extract from wastewater various types of pollutants flowing in it, including large amount of wipes;
  • the time required to service the screens was reduced by 90% to the necessary minimum;
  • there has been a significant decrease in the number of breakdowns and repairs at the downstream stages of wastewater treatment and sludge treatment;
  • the need to work in manual mode has been eliminated, through the use of automation of the operation mode.


The modernization of mechanical wastewater treatment at this pumping station carried out so far has made it possible to increase the efficiency of wastewater treatment of large and medium pollutants thanks to the use of catenary screens. These types of screens are equipped with a chain of special design and do not have any bearings and shafts in the part submersed in the wastewater. Thanks to such protection, further stages of wastewater treatment are also protected from the adverse effects of solids flowing in the wastewater.

In addition, MWWTP in Brodnica plans to expand the currently installed screenings collection system with a screw compacting press in the future. They plan to install it behind the screens, which would allow the press to receive debris collected by both screens, wash it, and then compact it and transport it to a trailer or container. The use of screw compacting press will make it possible in the future to reduce the volume and weight of the debris generated by up to 3 times.

The modernization of the mechanical wastewater treatment equipment at the Central Pumping Station on Piaski Street in Brodnica, which has been carried out so far, has fully met the set requirements and ensured stable and trouble-free operation of further stages of wastewater treatment.

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

Reference letter – Operation of the Esmil Aeration System in Chernigiv, Ukraine during the war

During 2018 in tank №3 and in 2019  in tanks №2 and №4  an aeration system at the municipal wastewater treatment facilities of “Czernihivvodokanal” has been replaced into tube air diffusers from the APKV-120 series with a total length of about 1700 m.

This allowed to reduce significantly electricity consumption, as the operation of one TV-300 blower fully satisfied the technological needs (previously there were two blowers). Total savings amounted to about one million UAH per year.

In addition, these diffusers worked very well during the period of active hostilities in our region, when electricity supplies were unstable.

In the period from March 15 to April 1, 2022, due to continuous shelling and significant damage to power facilities, the wastewater treatment plant of the city of Chernihiv was cut off from electricity. All the sludge and water mixture that was in the aeration tanks at the time of shutdown, sank to the bottom. Activated sludge in this form remained in tanks for two weeks.

After the electricity supply was resumed, the tanks were gradually put into operation (they were not emptied). After half an hour of work, the sludge and water mixture was mixed homogeneously, air was supplied evenly, and the required intensity of aeration was restored in all corridors of the aeration tanks.

This proves that the dispersion layer of the diffusers was not clogged with organic matter and did not require additional rinsing and blowing in order to restore its properties.

The efficiency of the aeration system has not decreased.

During the period of operation, there were no failures in the operation of APKV series diffusers. Moreover, a fairly quick recovery period after operation in conditions of long-term power failure was noted.

Case Study: Reconstruction and modernization of the mechanical treatment system at the wastewater treatment plant (Ostrów-Mazowiecka, Poland)

PROJECT: Reconstruction and modernization of the mechanical treatment system at the wastewater treatment plant located on Olszynowa Str. 16 in Ostrów Mazowiecka
CUSTOMER: Public utility company in Ostrów Mazowiecka Sp. z o.o.
SITE: Wastewater treatment facilities on Olszynowa Str. 16
COMMISSIONING: February – March 2021

Project Objectives

The objective of the project was to update and reconstruct the system of removing and collecting waste extracted from wastewater at the wastewater treatment plant in Ostrów Mazowiecka.

According to the modernization plan, the following equipment was delivered, installed and commissioned in February 2021:

  • Esmil RSK0815 step screen with 3 mm gaps
  • SGSM 0.9×2.6 (1.2) penstocks – 2 pcs.
  • Screenings compactor

Until recently, the wastewater treatment plant had been experiencing difficulties with overflowing the channel with wastewater, so it was decided to widen the channel and install a wider screen with a higher capacity.

Project Implementation

The equipment for the project was manufactured at the Esmil plant. The existing inlet channel was enlarged to properly position the screen according to the project requirements. After the completion of the construction work, the Esmil professionals proceeded to the installation and commissioning of the unit. The screen was commissioned in March 2021.


Thanks to the use of the Esmil RSK0815 step screen, the problem of overflowing the channel with wastewater was completely eliminated. The screen selected and supplied by Esmil not only keeps the mechanical treatment facility clean, but also, thanks to its reliable operation, protects the equipment on the further stages of the wastewater treatment process.

Reference on the operation of APKV-120 aerators (Budapest, Hungary)

The Southern Wastewater Treatment Plant in Budapest, with a capacity of 80,000 m3 per day, operates on the basis of the technology of biological wastewater treatment using activated sludge and aeration system regulated by the content of dissolved oxygen in 8 cascade aeration tanks.

Until the end of 2018, we used exclusively membrane aerators in the aeration system, and aerators of this type required replacement due to aging. After studying the international market, we decided in favor of using APKV tube air diffusers developed by Esmil and having the best technical specifications.

In 2018, the Esmil aeration system with APKV air diffusers was installed in the L4 aeration tank as the first step, and then in 2019 and early 2020, the same air diffusers were installed in the remaining 5 sections (L1-L3 and L5-L6).

Our experience with membrane diffusers after several years of operation can be described as follows:

  • Stretching of membrane plates;
  • Loss of elasticity of membrane plates;
  • The size of the air bubble increases due to the increase in the size of the perforation, and as a result, the oxygen dissolution efficiency decreases;
  • Physical damage, rupture of membranes;
  • Lack of oxygen at high loads;
  • Physical cleaning of the contaminated surfaces of the membranes does not fully restore their performance.

In order to maintain the required level of dissolved oxygen in the membrane aeration system, we had to empty the aeration tanks to inspect the membranes, clean them, and, if necessary, replace damaged membranes every two years. The main goal of replacing membrane aerators was to reduce excess maintenance costs of the aeration system.

The original APKV Esmil air diffusers were installed in the L4 aeration tank, which was 1/6th of the capacity (13,333 m3/day) of the total activated sludge flow rate. This was done for the purpose of comparison with the existing membrane system.

APKV Esmil air diffusers showed stable operation, the required intensity of aeration, the required parameters for oxygen saturation were achieved at a lower air pressure. SSOTE was 5 – 6.3%/m depending on the current air flow rate. The overall air consumption was reduced.

An additional positive effect was the significantly higher adaptability of the APKV Esmil system in terms of air supply regulation. New aeration system made it possible to more precisely and flexibly follow the changing oxygen demand, which makes it much easier to control the process and provides the necessary air supply, even during peak load periods.

As a result of the positive experience of operating the aeration system in the L4 aeration tank in 2019, a complete replacement of the aeration system was carried out in the same year and in 2020; APKV Esmil air diffusers were installed in the entire activated sludge system.

Experience in operating the aeration system using Esmil air diffusers:

  • Constant oxygen supply in the required amount during peak loads, DO 3-4 mg/l (including the last 8. cascade);
  • working pressure 535 mbar;
  • Reduction of pressure losses;
  • The air diffusers retain their shape, they are resistant to mechanical damage and corrosion;
  • The air diffusers do not get clogged.

Summarizing the above, it can be affirmed that the use of APKV Esmil air diffusers significantly reduces the need of service, and also meets the requirement for dissolved oxygen in activated sludge aeration tanks while reducing energy costs.

Case study: Brown’s Bay Packing Company (Campbell River, BC, Canada)

TYPE OF INDUSTRY – Fish processing
MODEL OF DAF-UNIT – FT-20Z with static mixer


The customer was looking for the solution to reduce pollutants in wastewater from the fish processing plant, after the FBR advanced oxidation process. Moreover, they were looking for the compact and easy to operate system, with low operating costs.


Based on initial information and theoretical calculations, Esmil in cooperation with our representative in Canada Archer Separation Inc. offered DAF-unit FT-20Z.

Wastewater Sourceseawater with fish farm byproducts
Operating Time16-20 h/day, 3-4 days/week
Flow Rate20-40 m3/h
Feed TSS Concentration800-1200 ppm
Effluent TSS Concentration80-100 ppm

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.



Esmil Group

Esmil Group stands as a premier global manufacturer, crafting cutting-edge equipment for wastewater treatment and sludge dewatering. Additionally, we specialize in delivering advanced membrane systems tailored to various industries.

EU Flag Esmil Group

Equipment for Wastewater Treatment & Sludge Dewatering.

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Equipment for Sludge Dewatering in the USA.

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Membrane Systems.