Since the 80’s, hundreds of anaerobic upflow granular wastewater treatment systems were built. Although a lot of these reactors still operate, they actually need an overhaul for technical or process reasons.

Paques has a number of designs with which these existing reactors, regardless of which supplier, can be rebuild to a new or better-than-new operational state. By providing a complete rebuild, including re-start assistance, a major overhaul is a good alternative for an entire new reactor.

Even though each reactor has its own needs for detailed engineering and tailor made parts, Paques rebuilds are basically based on proven standard designs and lead to an improved efficiency, lower maintenance, an unaltered plant lay-out, (re)use of existing equipment and an extended reactor life span.

Since a thorough planning and preparation is needed, taking the reactor off-line may involve a partial production stop or providing a by-pass to a (temporary) second reactor. Paques supplies full assistance with this and other jobs like storage of granular sludge and cleaning the reactor and scaffolding. A rebuild is in general the ideal moment for internal inspection of the reactor tank and piping.

Paques has developed rebuild packages for the following reactor types:

  • Rebuilds for non-Paques UASB’s
  • Rebuilds for Paques UASB’s, type Mk1
  • Rebuilds for underperforming EGSB reactors
  • Upgrading IC reactors for scaling conditions

More information

Please contact our service department.

Paques Environmental Technologies Inc.
t +1 781 365 1178

UASB Rebuild in BIOPAQ® design

“More satisfaction from your used anaerobic reactor”

Improve the reliability, life span and safety of your anaerobic reactor with a Paques UASB in BIOPAQ® design.

Many clients using a low-rate UASB reactor are struggling with the daily operation of their reactor. Over the years, Paques rebuilt and improved many reactors with typical shortcomings in materials, 3-phase separation and/or influent distribution.

By implementing an UASB® Rebuild in BIOPAQ® design, improvements were made to UASB's from Biothane, Biotim, Degremont and Seghers, by enhancing the operational stability and increasing the life span of the installation.


“Effective life span extension of your wastewater plant”

With the proven modifications of the Paques Service product range you can improve the reliability, life span and safety of your used UASB installation.

The splendid BIOPAQ®UASB modules originating from the 1980’s and 1990’s were usually built with polypropylene settlers a high quality hardwood frame. Although this frame prevented from severe corrosion, after decennia of continuous exposure to an unfriendly environment, the wood connections of many older UASB reactors show loss of strength. These weakened frames ultimately lead to problems with the discharge of water and biogas, endangering the continuity. A BIOPAQ®UASB Retrofit is the solution: easy and without interference in the existing plant lay-out.

Revisions up to BIOPAQ® performance

“Improve your existing EGSB installation”

Increase the capacity and life span of your ESGB by upgrading your present high rate anaerobe reactor with Paques’ separators and distribution systems. The Paques knowledge of particle separation and granular sludge biology has led to a detailed BIOPAQ IC reactor design with a high VLR and healthy biomass growth.

The cost effective EGSB upgrade packages are available for revision/improvement/upgrading of a variety of existing EGSB designs. They add operational improvement to your waste water treatment plant, are easy to implement and do not interfere with the existing plant lay-out. These advantages characterise the EGSB upgrade as an exciting and profitable improvement, which will supply you a reactor in a functional new state.

BIOPAQ®IC upgrade

“Adapt your PAQUES BIOPAQ®IC reactor to scaling conditions”

The increased scaling characteristics of some wastewater streams calls for adaptation of operation and techniques in your IC-reactor, in order to keep a high rate conversion process. The modifications of a BIOPAQ®IC Upgrade will help your dated IC reactor to treat influent with scaling properties for many more years.

The tailor-made alterations will prevent biomass deposition and loss of mixing in your IC reactor. Needless to say the refurbishment meets the specifications of the obsolete system for the water flow capacity and pre-pressure. The IC Upgrade is easy to combine with a thorough cleaning and inspection of the existing reactor, and will lead to an up-to-date reactor with many advantages.


At Paques, we believe in a cleaner, more sustainable world where innovation in biotechnology plays a crucial role in managing our planet's resources wisely.

If you have any questions or wish to explore what Paques technologies can do for your operations, we encourage you to connect with our team of experts. Our knowledgeable professionals are ready to assist you, offering insights and guidance tailored to your specific needs.

Leading the biotech revolution in wastewater and biogas

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Thank you for reaching out to Paques

Your inquiry is important to us, and we are eager to assist you in exploring our innovative solutions for biological wastewater and gas treatment.

A member of our expert team will be in touch shortly to discuss your specific needs and how Paques can help you achieve your environmental and operational goals.

We look forward to collaborating with you and hope to build a cleaner, more sustainable world together.

Warm regards,
The Paques Team