Pile Cloth Filter

500+ MITA® cloth disk filters are trusted at plants worldwide.

 

 

Your challenge:

Reuse, solids or Phosphorus Removal

Meet Class A Reuse requirements < 2 NTU: Reduce turbidity and increase UV transmittance in your effluent, consistently meeting Class A daily average < 2 NTU.

Reduce TSS to <5.0 mg/L: Remove solids from your effluent, consistently meeting levels of <5.0 mg/L suitable for re-use applications.

Reduce TP to <0.1 mg/L: Remove phosphorus from your wastewater and consistently meet levels of <0.1 mg/L.

Save space, time, and money: You’d like to do it on a compact footprint, and as usual, the simpler to install, easier to operate, and lower expense to own, the better.

Our solution:

The American-Made MITA® pile Cloth Filter

The centerpiece of the Nexom solution is the MITA pile cloth filter, a revolutionary disk filter with 500+ units installed globally.

Why a disk filter? Disk filters have a small footprint and can be installed into purpose-built or existing steel or concrete tanks

Why a pile cloth filter? Pile cloth filters offer high effluent quality from easy-to-maintain disks. Superior to fixed pore-size media with associated fouling risks and pressure sprayed backwash, and the pile cloth enables an outside-in flow that minimizes backwash with innovative suction cleaning shoes.

Why the MITA® Pile Cloth Filter?

The MITA system has enjoyed over 20 years of installation and service history in wastewater treatment, and has been installed on the largest cloth filter plant in Europe. MITA’s evolution of the tried-and-true cloth disk filter delivers the highest reliability in the smallest footprint in its class.

The MITA cloth filter includes three product families to serve the needs of the industry, all using the same high-quality reuse-ready media:

  • The drum filters meet the needs of the smallest continuous or intermittent use dischargers, while its disk filters can accommodate flows ranging from average American municipal needs to the largest plants in the world.
  • The horizontal disk family is scalable from 54 to 1720 ft² active filter area per parallel filter.
  • In some applications the hydraulic profiles demand a smaller footprint and lower height filter, which can be accommodated by our patent pending family of vertical shaft disk filters.

All models arrive to site with a factory-installed backwash system using submersible pumps to minimize system footprint and installation costs.

Safety receives superior attention in MITA cloth disk filter systems so that all access and maintenance requirements are planned from project inception to minimize any risks to the operators. Nexom emphasizes the highest level of factory configuration and assembly to minimize installation costs onsite and maintain the highest quality control.

At-a-glance:

Key Advantages:
  • Smallest footprint with the lowest hydraulic profile: tightest disk spacing in its class, no externally mounted pumps or control valves external to the filter as a standard offering.
  • Horizontal or plug-and-play vertical disk configurations.
  • Factory-installed backwash system and access platforms.
  • Produces Class A reuse of < 2 NTU,/5 mg/L TSS.
  • Reduces phosphorus down to <0.1 mg/L.
  • Addresses your stormwater or CSO management needs.
  • Reuse-approved options of 5 or 10 µm media.
Applications:
  • Reuse
  • Phosphorus removal
  • Tertiary filtration
  • Post-lagoon TSS filtration
  • Membrane pretreatment or backwash treatment
  • Precipitate removal
  • Microplastics removal
  • Stormwater and CSO management

How it works

MITA pile cloth disks continuously filter during all aspects of the filtration cycle.

Influent enters and floods the MITA filter tank, flowing outside-in through the pile cloth media that provides depth filtration for suspended solids. Filtrate from all disks is collected into a central tube and passes into an effluent chamber with a fixed effluent weir. The filter basin includes an overflow and foam weir, which partially bypasses excess flow in cases where the prevailing conditions exceed the filter design capacity. The normal state of operation is passive filtration, where all filter disks are stationary.

Building a better backwash

As the water passes through the reuse approved filter media, solids accumulate in the pile cloth media increasing the filter headloss. Tank level gradually increases to a set point elevation in the tank for backwash initiation.

When the backwash is initiated, the dynamic backwash state of the filter is initiated. Disks rotate past MITA’s molded suction shoes that remove accumulated solids from the filter media. Disks are backwashed in clusters of up to four disks at a time, and the dynamic backwash cycle is complete in <5 minutes even on the largest filters. The cleaning cycle is also set to initiate on a timer basis as required. All disks or blanks must be in place to allow backwashing.

  • Backwash does not disrupt filtration since only a small fraction of the filter disk surface is under the backwash suction shoe at any given time.
  • Backwash is reduced by 20-40% and clean-in-place chemicals by up to 20% compared to competing filter design by enabling reverse rotation during backwash cycles, which provides more thorough cleaning.
  • The engineered injection molded polyethylene vacuum shoes extends filter cloth life by avoiding excessive cloth wear.
  • TSS can settle in the filter basin during high TSS events or low flows, and Nexom’s control system automates a sludge removal pump to control accumulation and sludge degradation in the filter.

Cutaway view of Nexom’s MITA cloth disk filter.

What it Delivers

Effluent quality that comes pre-configured

The standard configuration for the MITA filter is to include pre-configured, factory-mounted submersible backwash pumps dedicated to discreet clusters of disks in the filter assembly. More than just reducing footprint and installed costs, this provides a level of mechanical redundancy that can be beneficial between maintenance events. Our level of factory assembly directly reduces onsite construction costs.

Want to know what MITA® pile cloth filters could do for your treatment plant?

Submit your RFP today and our on-staff professional engineers can help you size and design a MITA cloth disk filter to meet your wastewater treatment requirements.

FAQ

What about ultra-low Phosphorus limits below 0.1 mg/L?

We have a solution for you: Blue PRO reactive filtration is designed to efficiently meet ultra-low phosphorus limits as low as <0.02 mg/L.

Can the system be installed into pre-existing tanks?

Nexom’s MITA  technology is flexible and can be compatible with both new and existing tanks. Contact our project development team to learn how your specific tanks could be retrofitted with  a MITA  system.

How much does a typical system cost?

There are many factors which can influence the cost of the MITA process, including design flows, loading, treatment requirements, and existing infrastructure. The best way to determine the cost for your specific application is to submit your RFP to our project development team.

Why pile cloth filter media instead of fixed-pore space media?

Pile cloth filter media is preferable in many cases to fixed-pore media because it provides depth filtration and superior performance to the same nominal pore size, but it is less prone to fouling. During the vacuum backwash process, the pile cloth that typically lays flat along the surface of the media is pulled into an upright position. The open backing and the motion and flexibility of the cloth fibers allows trapped solids to be released more easily into the backwash; particles are less likely to become lodged in the filter media and require manual disk maintenance or other interventions. Lastly, the backwash system in a pile cloth filter simply reverses the filtrate flow through an comparatively open vacuum shoe that accommodate debris and rags, whereas fixed pore media often require makeup backwash water delivered through pressure nozzles.

Why utilize an outside-in flow path?

The outside-in flow path allows for filtrate reversal using vacuum cleaning of the cloth media, rather than cleaning with pressurized water or requiring an external washwater source. Vacuum backwash also prevents forcing of particles into fixed pore spaces of inside-out media, reducing long term fouling. Lastly, particles removed by vacuum backwash are drawn directly into the sludge removal piping, eliminating the need for settling of backwashed particles, which improves filtration of neutrally buoyant or lighter than water particles such as algae.

What type of treatment processes can this follow?

These have been successfully implemented after all type of plants, including lagoons, industrial clarifiers, SBRs, MBBRs, and extended aeration.

Where are these made and are they BABA compliant?

Nexom has long-established manufacturing in the USA, and is a manufacturing licensee for the MITA cloth disk filter. BABA-compliant systems will ship from its facilities in the Midwest.

What about activated carbon and microplastics?

MITA’s installation list includes long-standing operations for powdered activated carbon sequestration and removal. Studies demonstrate an estimated 80% reduction in microplastics through the MITA cloth disk filter.

Have a question that wasn’t answered here?

Contact one of our product specialists (or your local Nexom rep) and we’d be happy to answer it.