Could fish clean up sewage works?

A FEW tankfuls of fish could put a stop to the devastating blooms of algae caused when sewage works discharge effluent into rivers and lakes.

Most sewage works remove solids from raw sewage and get rid of organic matter with the help of sludge-dwelling bacteria. But few remove dissolved phosphorus and nitrogen from detergents and fertilisers. When too much of these nutrients get into fresh water, they can trigger explosive growths of algae. All the oxygen in the water is used up when the algae decompose, suffocating aquatic life. Some blooms also generate dangerous toxins.

So Ray Drenner, a biologist at the Texas Christian University in Fort Worth, has developed a waste-water purification system in which algae consume these polluting nutrients before the water is discharged. Fish then nibble away at the algae, incorporating the nutrients into their bodies or excreting them. The faeces sink to the bottom of the tank for regular collection and disposal.

In Drenner's system, which he developed with Laura Rectenwald of Baylor University in Waco, the outflow from a sewage treatment works passes through a series of tanks containing an algae-eating African fish called Tilapia mossambica (pictured above and right). The tanks are fitted with vertical plastic screens on which periphyton algae, which thrive on nitrogen and phosphorus, grow (see Diagram, right).

"The fish spend the whole day grazing the screens, cropping them almost to a fine velvety layer," says Drenner. The layer of algae constantly regrows.

Drenner stresses that the system will work only after sewage has undergone conventional treatment. The fish would serve as a "polishing" step to clean up the water before its final discharge. When fed with water from a sewage works in Waco, the system removed 82 per cent of the phosphorus and 23 per cent of the nitrogen.

In its current form, the system occupies a large area, making it unsuitable for treating water from big treatment

Contact: Claire Bowles
New Scientist

Page: 1 2

Related biology news :

1. Endometriosis: Could angiostatic therapy be the new treatment of the future?
2. Could mice hold the secret to longer life?
3. Could vitamins raise levels of bad cholesterol? Animal study suggests they might
4. Could memory performance and spatial learning be genetically based?
5. Could a specific protein contribute to erectile dysfunction for the diabetic and obese?
6. Could diabetes treatments fight cancer?
7. Could rice be the source for a natural herbicide?
8. Could hibernators hold the key to improving organ preservation?
9. Could Bt transgenic crops have nutritionally favourable effects on insects?
10. Could one less cookie a day help the fight against fat?
11. Could an anti-marijuana compound hold the key to body weight and appetite control?

Post Your Comments:

(Date:6/2/2016)...   The Weather Company , an IBM Business (NYSE: ... capability in which consumers will be able to interact with ... via voice or text and receive relevant information about the ... Marketers have long sought an advertising solution that can create ... relevant and valuable; and can scale across millions of interactions ...
(Date:6/1/2016)... NEW YORK , June 1, 2016 ... Biometric Technology in Election Administration and Criminal Identification to ... According to a recently released TechSci Research report, " ... Sector, By Region, Competition Forecast and Opportunities, 2011 - ... $ 24.8 billion by 2021, on account of growing ...
(Date:5/20/2016)...  VoiceIt is excited to announce its new ... By working together, VoiceIt and VoicePass will offer ... take slightly different approaches to voice biometrics, collaboration ... usability. Both ... "This marketing and technology partnership allows ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... SAN DIEGO , June 27, 2016  Sequenom, ... company committed to enabling healthier lives through the development ... Supreme Court of the United States ... Federal courts that the claims of Sequenom,s U.S. Patent ... the patent eligibility criteria established by the Supreme Court,s ...
(Date:6/27/2016)... June 27, 2016  Liquid Biotech ... funding of a Sponsored Research Agreement with The ... cells (CTCs) from cancer patients.  The funding will ... levels correlate with clinical outcomes in cancer patients ... will then be employed to support the design ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... Researchers at ... most commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are the ... read it now. , Diagnostic biomarkers are signposts in the blood, lung fluid ...
(Date:6/23/2016)... SPRING, Md. , June 23, 2016 A ... collected from the crime scene to track the criminal down. ... and the U.S. Food and Drug Administration (FDA) uses DNA ... Sound far-fetched? It,s not. The ... genome sequencing to support investigations of foodborne illnesses. Put as ...
Breaking Biology Technology:
Cached News: