Bruce Jefferson of the Centre for Water Sciences, at Cranfield University, England, and colleagues explain that water shortages due to low rainfall and increasing water demand have highlighted the need to implement more effective water conservation measures. They point out that the development or urban gray water recycling could represent a partial solution to the growing problem.
Gray water, also known as sullage, is non-industrial wastewater generated by domestic dish washing, laundry and bathing. Its use in non-potable applications could significantly reduce demand on domestic water consumption. The team highlights a recent study that showed that sullage re-use could reduce consumption by as much as 15 to 55 litres per person per day in a domestic setting.
However, gray water is not without hygiene and disease concerns regarding its direct use so efforts are underway to find ways to process it passively at little energy cost. Constructed wetlands, such as rooftop water recycling systems are one option and Jefferson and his colleagues have now investigated the pros and cons of three such systems. They studied the efficacy of using a Horizontal Flow Reed Bed (HFRB), Vertical Flow Reed Bed (VFRB) and a patented artificial wetland (the Green Roof Water Recycling System (GROW).
They compared how each system fared in treating sullage over a period of nine months. They monitored the influent and effluent using standard water quality parameters, as well as measuring the organic fraction before and after treatment. The team found that all three wetlands reduced key pollutants found in sullage as well as reducing the presence of indicator microorganisms. As one would expect, water-soluble, as opposed to oily, or hydrophobic, contaminants were removed preferentially. The GROW system was most effective.
"This case study has demonstrated the potential of low-cost reed beds and the novel ‘GROW’ constructed wetland system to treat grey water for reuse," the researchers say. They point out that further work is now needed to assess how well such constructed wetlands cope with more highly contaminated sullage before such systems are ready for widespread adoption.
Albert Ang | alfa
Northeast-Atlantic fish stocks: Recovery driven by improved management
04.02.2019 | Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei
New mathematical model can help save endangered species
14.01.2019 | University of Southern Denmark
An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.
In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....
Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.
The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...
For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.
The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...
Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens
Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...
Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light
When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...
11.02.2019 | Event News
30.01.2019 | Event News
16.01.2019 | Event News
22.02.2019 | Physics and Astronomy
22.02.2019 | Materials Sciences
22.02.2019 | Life Sciences