The UN’s 2017 World Water Development Report was published on 22 March – on World Water Day – and is entitled “Wastewater: the Untapped Resource”. REMONDIS Aqua not only supports this global message wholeheartedly, it also has a number of solutions to offer in this area.
The choice of this year’s subject is closely connected to the 2030 Agenda for Sustainable Development that was adopted by the UN’s General Assembly in autumn 2015. Goal 6 of this agenda is to “ensure access to safe water sources and sanitation for all” and lists a number of targets. One of these is, for example, to halve the proportion of untreated wastewater and substantially increase recycling and safe re-use globally. The General Assembly has, therefore, made it very clear that wastewater is no longer simply a product that must be disposed of but must be seen as a resource that can be re-used. Treated wastewater can be put to good use as a substitute for fresh water – e.g. to irrigate crops or in industrial processes. What’s more, important substances can be recovered from the wastewater that can be recycled or used to generate energy.
Energy efficiency levels at the municipal sewage treatment plants being run by the REMONDIS Group are continuously being improved by using sludge digestion and co-digestion, both of which produce enough energy to cover most of the plant’s requirements. The facilities that the company uses at its industrial customers go even further with the Re2Energy process producing up to 50 percent more energy than is needed. Wastewater treatment can, therefore, be a great source of energy.
The family-run company attaches great importance to research and development work
Besides generating energy, REMONDIS also focuses on recovering vital substances from the wastewater. Around 2 million tonnes of dewatered sewage sludge are generated in Germany every year which contain approx. 60,000 tonnes of phosphorus. A significant amount, therefore, which could be recovered and recycled – especially as natural reserves around the world are gradually being depleted and the quality of these reserves is deteriorating rapidly. REMONDIS
has been looking into this subject for many years now and has developed a number of processes that are creating the groundwork and setting standards for recovering phosphorus.
Its intention here is to enable the phosphorus to be used as a fertiliser as well as for it to be supplied to industrial businesses as valuable phosphates. Indeed, this family-run company attaches great importance to research and development work. Well aware that this raw material is becoming ever more scarce, the experts have been looking closely at finding ways to recover and recycle phosphorus – as phosphorus is vital for plant and animal life and, of course, for humans, too. With our planet’s natural supplies of phosphorus becoming harder and harder to come by, REMONDIS has intensified its efforts to recover phosphorus and is now running its first pilot plant together with HAMBURG WASSER to recover phosphorus from sewage sludge ash.
Thanks to its award-winning TetraPhos® process, REMONDIS Aqua can recover vital raw materials for re-use – including phosphoric acid, gypsum, iron salts and aluminium salts
What is particularly special about this innovative TetraPhos® process is the fact that sewage sludge ash containing phosphate is dissolved in diluted phosphoric acid. The phosphoric acid solution is enriched with the phosphate from the ash and then treated in four different stages. Various products are available at the end of the process including RePacid® phosphoric acid (used to produce phosphates, incl. fertilisers), gypsum for the building supplies industry and iron and aluminium salts which can be returned to the sewage treatment plant and used as precipitating agents to eliminate phosphorus. This all helps to conserve considerable amounts of natural resources: not only can up to 500kg of phosphoric acid be produced from 1,000kg of ash but also over 500kg of gypsum for the building supplies industry and iron and aluminium salts for treating wastewater at sewage treatment plants.
A further process deployed by REMONDIS is to recover a high quality fertiliser straight from industrial wastewater. By using its RePhos® system, the company is able to remove phosphorus and nitrogen from the wastewater so that they can be re-used immediately.
Watch this film to find out more about the innovative TetraPhos® process – the winner of the 2016 GreenTec Award (Recycling & Resources category) (German only)