- Title: New waste water system promises eco benefits
- Date: 10th July 2017
- Summary: HELSINGBORG, SWEDEN (MAY 16, 2017) (REUTERS) (SOUNDBITE) (English) MARINETTE HAGMAN, R&D MANAGER FOR SWEDEN WATER RESEARCH, SAYING: "The new way will be much more compact. There's this huge plant here and you see all the basins around, and the new one will focus on using the resources in a much more efficient way than we do today." VARIOUS OF THREE PIPES BEING BUILT INTO OCEANHAMNEN BUILDINGS HAGMAN WITH LARGE PIPE USED TO DEAL WITH RAINWATER
- Embargoed: 24th July 2017 10:24
- Keywords: Helsingborg Oceanhamnen toilet sewerage poo waste water sewer sewage waste
- Location: HELSINGBORG, SWEDEN
- City: HELSINGBORG, SWEDEN
- Country: Sweden
- Topics: Science
- Reuters ID: LVA0036P4WDI3
- Aspect Ratio: 16:9
- Story Text: A unique sewage system is being built in a new district in the northern Swedish city of Helsingborg, which local waste water managers believe will be a blueprint for increasing sustainability in urban areas.
Hamse Kjerstadius, a chemical engineering doctoral student at Lund University Faculty of Engineering, was one of those whose work was included in the plans.
He told Reuters: "Our system today is quite poor, because we mix all the waste waters into one big pipe. We have large flows from all the open areas in the city containing heavy metals and pollutants from cars and all the streets. Everything that pours into our cities ends up in the waste water pipe and gets mixed with the beneficial fractions from toilet water. Urine and faeces are really good fertiliser, but we should not mix them with other waste waters."
The plan being implemented by Sweden Water Research includes food waste being ground in a garbage disposal unit next to the kitchen sink, while household toilet waste would go direct to the sewer without coming into contact with the kitchen and bath water.
Food waste and toilet waste are transported separately to a wastewater treatment facility nearby to make plant nutrition and biogas.
"It's a sewer separation system, so we separate the waste water at the source in the household," said Kjerstadius. "The toilet waste water goes into one pipe, the food waste into a separate pipe, and the remaining household waste water into a third pipe. So we can recover far more resources from the waste water."
Kjerstadius - and Marinette Hagman, R&D manager for Sweden Water Research - say using source-separated systems could double biogas production from sewage sludge and increase the return of nitrogen and phosphorus nutrients to agriculture by 700 and 300 per cent.
"We think we can treat waste water in a much more efficient way by other processes in the new treatment plant," said Hagman.
"It's quite easy," said Kjerstadius. "You collect toilet waste water with a vacuum toilet, which reduces the amount of water that you use. That means we get the nutrients and the water resources in a more concentrated form. We can recover them more easily and at a lower energy cost at the waste water treatment plant."
The global nitrogen cycle is identified by environmentalists as one of the main challenges we face, potentially more serious than global warming. Large natural flows of nitrogen move from the atmosphere into the ecosystem and many climate scientists say human activities, including our release of nitrogen in wastewater, have dramatically altered the cycle.
Kjerstadius says returning the nutrients into the fields will help counter this, acting as high-quality plant nutrition for arable land.
Initial estimates are that the cost of building such a sustainable systems to replace existing sewer systems would be 25 percent higher than replacing them like-for-like, but Kjerstadius believes this is outweighed by the environmental benefits in urban areas.
Sweden Water Research are adapting their Helsingborg waste water plant to accommodate the new system due for trial in a brand new district called Oceanhamnen (Ocean Harbour) where 320 apartments and workplaces for a total of 1,600 people will be completed in 2018.
"The new system will be much more compact," explained Hagman.
Three similar pilot projects are ongoing in the Netherlands, Germany and Belgium, although Kjerstadius points out these other initiatives do not provide a separate processing system for food waste, nor focus as much on the re-uses of nutrients.
- Copyright Holder: FILE REUTERS (CAN SELL)
- Copyright Notice: (c) Copyright Thomson Reuters 2017. Open For Restrictions - http://about.reuters.com/fulllegal.asp
- Usage Terms/Restrictions: None