A state-of-the-art water purification plant located in Budapest uses plants in greenhouses to provide full tertiary sewage treatment. As part of the United Nations World Water Day celebrations, this facility was open to the public. The biological water treatment plant uses technology created by the firm Organica Water to treat effluent from 300,000 residents and it has been in operation since 2012. The facility is one of three large-scale advanced sewage treatment plants in Budapest, Hungary; we’ve included a number of slides from a tour of the facility on March 21, 2015.
A smaller sewage treatment plant based on the same green technology opened in October of 2014 in Sechelt, BC. The level of sewage treatment in British Columbia varies. The City of Victoria discharges sewage into coastal waters, while the Iona Island and Lions Gate treatment plants in Metro Vancouver only provide limited primary treatment. Upgrades in waste water treatment could improve the quality of coastal waters. Could green technology that make use of plants to clean water be an option for more BC municipalities in the future?
The “Living Machine” technology utilizes plants housed in greenhouses to undertake much of the secondary treatment of waste water. How can plants clean water? The long roots of specially selected plants come into contact with waste water circulating through the system, in a multistage process. Some of the roots grow up to 2.5 metres long and provide a lot of surface area for biological cleansing of the circulating water; a number of microorganisms also assist in the process. Bio-gas created in the process is utilized to generate all of the electrical power needed for the plant. We’ll provide more details on the entire process later on (a brochure of the plant is available as a PDF). For contrast, we’ve also included a few photos of another advanced water treatment in Budapest that uses more traditional technology to treat sewage from 1,600,000 residents.
The purified water produced by the Living Machine technology is cleaner than the Danube River (where it is discharged). The photo below (upper left) shows the clean, discharged water, the water during the treatment process, and the incoming waste water. Before the water is discharged, it is treated with UV light. The quality of the water would exceed the environmental standards for discharge into an inland lake.
The steps in the water purification process are as follows:
- incoming sewage is first run through a very coarse screen
- the waste water is sent into a deep pool so large, heavy rocks and other particles can be separated (via gravity)
- the waste water is fed into large tanks for primary treatment to separate out sludge and heavy particles; a large arm slowly spins around the cylinder-shaped tank (once every 45 minutes). Heavy sludge is pumped out from the bottom of the tanks
- sand and oils are separated from the water
- the water is circulated through the greenhouses in a number of channels around the plants, through various aerobic and anoxic zones in a food chain reactor (details here)
- lights are turned on when needed in the greenhouses, and the temperature is kept well above 13 degrees Celsius so the facility can operate 24/7
- the separated sludge is processed in 7 silos, in an aerobic environment over 14 days, at a temperature of 30-37 Celsius; this process produces bio-gas that is utilized to produce all of the electrical power for the plant
- the processed sludge is further concentrated with centrifuges; approximate 3 to 4 truck loads are shipped away daily for disposal
- after the water treatment is completed in the greenhouse, it is circulated into large tanks. very fine particles settle at the bottom of the tanks and this is pumped back into the greenhouses for treatment
- the remaining clean water undergoes a final UV treatment before discharge (UV is used instead of chlorination)
The following YouTube videos have footage of the Living Machine (full name of facility: South-Pest Water Purification Plant or Dél-pesti Szennyvíztisztító Telepen located at Meddőhányó utca 1, 1238 Budapest, Hungary):
More details on the World Water Day on March 22, 2015 celebrations are on the United Nations website:
The largest sewage treatment plant in Central Europe is also located in Budapest and it serves 1,600,000 residents. The Central Budapest Sewage Treatment Plant (Budapesti Központi Szennyvíztisztító Telep) opened in August of 2010. Prior to the opening of this facility, only 50% of the city’s waste water was treated. After the facility came online, the percentage of treated waste water climbed to 95% (and it’s currently at 96%). There are a number of innovations at this facility as well. Green roofs cover 74% of the buildings. All of the tanks are covered and the water processing is enclosed; hence the odours are contained and filtered on the site. The photos below were taken on a tour of the facility on World Water Day 2015.
The water first undergoes primary treatment (mechanical separation, large particles). Oils and sand are then separated. The waste water is aerated and biologically treated with the help of microorganisms. Phosphorus and nitrogen is removed through a number of steps. The resulting sludge is heated, concentrated during processing and bio-gas is collected in large tanks. The bio-gas generates around 65% of the electricity used in the facility. The resulting water can be used for industrial uses or it can be discharged into the Danube River.
Waste water facilities that have secondary treatment are a significant improvement over primary treatment. In Metro Vancouver, two out of five plants are primary (Iona and Lions Gate). The Metro Vancouver website describes the goal of primary treatment to remove “50 to 60 per cent of the total suspended solids (TSS) and 30 to 50 per cent of the biochemical oxygen demand (BOD).” Secondary treatment sites in the region are at Northwest Langley, Annacis Island and Lulu Island. There have been concerns with the quality of discharged water over the years (see Metro sewage plants failing federal tests). Should there be more emphasis in Metro Vancouver in improving waste water treatment?
It’s worth noting that the Greenest City Action Plan (GCAP) passed on July 5, 2011 included the following 1-3 year goals:
- Strengthen advocacy and leadership role through the Regional Engineers Advisory Committee in order to help advance regional water quality improvement and sewage treatment initiatives and extend the life of drinking water sources
- Eliminate combined sewer overflows from sewage outfalls at Crowe and Burrard Streets and develop Integrated Stormwater Management Plan.
The GCAP “improve water quality” report also showed that one of the top three ideas from the public was to “Improve sewage treatment to include tertiary treatment.” Should the City of Vancouver review the status of the Greenest City Action Plan with respect to the water quality objectives? What more could the City do in the future to improve water quality?
Water is Our World World Water Day 2015 Official Trailer (more details on twitter at #WaterIs and #WorldWaterDay)
Further information on the Sechelt Water Resource Centre is available in the following websites:
City of Sechelt Wastewater Treatment Facilities Project
Sechelt’s New Wastewater Treatment Facility Opened (Duane Burnett, October 16, 2014)
Average day flow: 4000 cubic metres per day (Current system: 2200 cubic metres per day)
Peak flow: 6000 cubic metres per day Peak hourly flow: 500 cubic metres per hour (12,000 cubic metres per day)
Population Capacity: 14,000 people (Current system connected population: 6,000 people)
Future Expansion Capability: to 8000 cubic metres per day or population of 28,000 people
The Living Machine water treatment technology is scalable. The largest treatment plant that uses Organica’s Food Chain Reactor technology is currently the one in Budapest, Hungary with a capacity of 80,000 cubic metres per day. Other sites in France, Hungary, China, Poland, Indonesia, India and Austria also have installed water treatment facility using this technology. The Sechelt, BC facility is the first facility in Canada, and it also meets LEED Gold standards.