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 EKOTON and having the best technical specifications.

In 2018, the EKOTON 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 Ekoton 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 Ekoton 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 Ekoton 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 Ekoton air diffusers were installed in the entire activated sludge system.

Experience in operating the aeration system using EKOTON 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 Ekoton 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
START OF OPERATION – 2019 March

Issue

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.

Solution

Based on initial information and theoretical calculations, EKOTON 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: 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
YEAR OF COMMISSIONING – 2020

Introduction:

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)

MODEL OF DEHYDRATOR – MDQ-354(2) CL
START OF OPERATION – 2020 June

Issue

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.

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)

MODEL OF DEHYDRATOR – MDQ-354 C
START OF OPERATION – 2018 August

Issue

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.

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 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)

MODEL OF DEHYDRATOR – MDQ-353 C
START OF OPERATION – 2020 February

Issue

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.

Solution

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)

MODEL OF DEHYDRATOR – MDQ-102 C
START OF OPERATION – 2019 November

Issue

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.

Solution

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.

Results

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
MODEL OF DEHYDRATOR – MDQ-354 CL
START OF OPERATION – 2020 January

Issue

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.

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 technology based on Multi-disc Screw Press Dehydrator MDQ-354 CL together with service platform.

Results

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
MODEL OF DEHYDRATOR – MDQ-353 C
START OF OPERATION – 2018 December

Issue

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.

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 technology based on Multi-disc Screw
Press Dehydrator MDQ-353 C.

Results

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%