Biosolids management and by-products recovery

Increasing urbanisation and rapid industrial development is fueling demand for treatment of biosolids and biowaste. As a by-product of wastewater treatment, sludge poses a major economic and environmental challenge – and opportunity – for industrial businesses.
Your challenges

Optimising the treatment of effluent and wastewater

Enhancing the effectiveness of wastewater and effluent treatment is an urgent priority for industries. Operators seek to increase operational efficiency and drive down operational and energy costs while reducing environmental impact.

Surging demand or the need to combine biosolids or biowaste from multiple plants requires capacity expansion. Many are also faced with ageing or underperforming infrastructure, amplifying the challenge.
Our solutions

Industry-leading biosolids solutions to meet your organic and biowaste challenges

SUEZ has extensive expertise and experience in biowaste and biosolids management. Our proven technologies and customised solutions help industrial businesses meet their water, process water, wastewater and organic waste treatment challenges.
Our Monsal Advanced Digestion Technologies optimise digestion, utilising multiple biological hydrolysis pretreatment systems to condition the sludge before anaerobic digestion. By exposing sludge to different temperatures and specific retention times, it delivers increased digester capacity and biogas production, maximises the destruction of volatile solids and enabled sludge to meet Class A or Class B standards.

Advanced anaerobic digestion
Our advanced anaerobic digestion processes increase efficiency and minimise energy costs, and are designed to work as part of a full integrated system comprising desludging, mixing, heat exchange and pretreatment.

Our AirLift system automates the removal of primary sludge and humus sludge from multiple settlement tanks by injecting air into the sludge pipe upriser to create a differential pressure that induces flow. Sludge is then available for thickening operations prior to anaerobic digestion.

Sequential Gas Mixing (SGM)
SGM ensures the continuous mixing of anaerobic digesters continuously without thermal layering and accumulation of volatile fatty acid pockets, with moving parts located externally for ease of servicing. It offers the lowest parasitic power of any digester mixing system, particularly for thick sludges and sludges from advanced digestion processes.

Heat exchangers
Our lines of heat exchanger equipment are specifically designed to handle thick sludge and difficult duty applications, using available on-site sources to provide maximum energy transfer to the sludge. We offer a range of solutions for heating applications, high heat transfer, post-pasteurisation and independent control of digester temperature.

Flexible contract models
SUEZ offers a wide range of commercial contract models, each tailored to the individual needs of your business and its sites. Our offerings range from equipment hire right through to packaged solutions for design, build, operation, maintenance and finance.

Our references

They trust us

Our technologies are delivering sustainable solutions to industrial businesses around the globe, recycling biosolids into methane and valuable by-products.


Discover more about our success stories.

Our innovations

Aiming for energy-neutral wastewater treatment

Energy can account for as much as 30 per cent of a wastewater plant’s operations and maintenance budget. SUEZ offers leading edge solutions to harness energy and other benefits from wastewater by-products.

Biological Hydrolysis (BH)
Our advanced BH technology is a flexible, multi-stage acid phase digestion pretreatment system that increases the efficiency of anaerobic digestion. Uniquely, the flexible system allows variation in temperature and hold times, enabling the production of a pathogen-free Class A biosolid that can be used as an alternative to synthetic fertilisers. It also enables:

  • digestion capacity expansion
  • increased gas yields
  • decreased operational costs, and
  • reduced carbon footprint.


Adding organic waste to the anaerobic digestion process helps increase biogas yields for conversion into renewable energy. Re:Sep is a multi-step process for organics separation that captures more than 95 per cent of organic material through high-efficiency separation of organic and contamination streams. The proven and robust system is capable of treating waste streams with contamination levels of up to 30 per cent, and even higher when throughput is reduced.

Re:Sep features a modular and scalable design to handle small or large flows of both liquid and solid waste, and produces an ideal digester feed substrate suitable for pumping, mixing and heating.