Sludge Treatment

Sludge recycling: make better use of your resources

Yesterday's constraints are today's opportunities: sludge naturally generated by wastewater treatment plants and wastewater treatment can be a valuable asset. Veolia Water Technologies supports all public and industry stakeholders to manage biosolids: an economic issue as well as an environmental issue.    

Sludge treatment: a major environmental challenge

The treatment of industrial and domestic wastewater is a central issue for public safety and the environment. Since 2010, it is estimated that 5.5 billion cubic meters of wastewater was produced in France – that’s a volume of 175,000 litres needing to be treated every second across approximately 18,000 wastewater treatment plants in the country. Sludge treatment processes aim to avoid risks to the environment, and respect the water cycle and its circular economy.    

Over the past several decades, Veolia Water Technologies has earned a reputation as the recognised specialist in wastewater treatment and new sanitation technologies. With global technological leadership, the Veolia Group has developed patented, innovative solutions to meet the needs of large industries as well as local authorities and public entities.

Which technologies for sludge treatment?

The solutions developed by Veolia Water Technologies enable compliance with strict specifications—reduction of mud produced during wastewater purification, optimised valuation of remaining sludge, quality standards for effluents and sludge—as well as absolute respect for environmental standards. Discover some of the technologies used below.

Exelys™ and Biothelys™: thermal hydrolysis

Exelys™ and Biothelys™ have developed a sludge treatment technique based on the principle of thermal hydrolysis, coupled with anaerobic digestion and biogas generation. This solution significantly reduces the amount of organic sludge generated during water treatment processes—up to 35% less solids—leading to an additional 30-50% biogas production.


Anita™: nitrogen sludge treatment

The main objective of the Anita™ range is treating nitrogen concentrations naturally present in certain sludge and wastewater, in order to better guarantee the reuse or valorisation of treated flows. The compact device meets the latest applicable standards and is distinguished by a very low energy consumption – which is close to true self-sufficiency.


Bioco™: optimised thermal drying

Rapid sludge drying is an unavoidable and essential process for recovery and extraction. Bioco™ technology breaks new ground by introducing the principle of an opposite circulation of sludge and drying air – heated up to 170 ° C – within the circuit. The device allows optimal recovery of valuable biosolids while eliminating any risk of material ignition.


Solia™: greenhouse drying

Solia™ is the reference technology for solar sludge drying. The process takes advantage of natural heat generated by the sun to quickly dry materials stored under glass. The solution is aimed at both public authorities and small and medium-sized businesses looking for a compact, economical and environmentally friendly sludge treatment solution.


Pyrofluid™: ash incineration and recovery

Pyrofluid™ solution promotes the rapid and efficient removal of primary and secondary sludge by incineration in a fluidised bed furnace. Brought to a temperature of 850°C, the sludge instantly combusts—in around two seconds—generating a bed of ash that can be upgraded downstream. Pyrofluid™ is an ideal technology for large urban communities and certain industries.

Athos™: total elimination by oxidation

Athos™ technology is based on the principle of wet oxidation or OVH. This innovative solution focuses on the mineralisation of sludge. The sludge is preheated and then injected with high doses of pure oxygen to generate a mineral solid.


For the production of biogas to farm fertiliser, sludge treatment and related technologies continue to improve. Don’t hesitate to contact Veolia Water Technologies now for a better valorisation of your resources.