Featured Research

from universities, journals, and other organizations

Simple way to precipitate phosphorus from the wastewater of a pulp mill

Date:
November 21, 2012
Source:
Aalto University
Summary:
Researchers have developed a simple method for reducing the amount of phosphorus in the wastewater of a pulp mill. The method is called simultaneous precipitation using iron sulphate. A separate treatment stage is not required, as the precipitation takes place simultaneously with the actual biological wastewater treatment.

Researchers at Aalto University, Finland have developed a simple method for reducing the amount of phosphorus in the wastewater of a pulp mill. The method is called simultaneous precipitation using iron sulphate. A separate treatment stage is not required, as the precipitation takes place simultaneously with the actual biological wastewater treatment.

Related Articles


Iron sulphate is added to the wastewater prior to the biological wastewater treatment process, and the phosphorus dissolved into the water is precipitated with the biomass at the treatment plant. Finally, the phosphorus is removed from the plant with the sludge. In Finland, sludge is generally burned, in which case the phosphorus would end up in the ashes and would thus be reusable in the form of fertilizers, for example.

"At best, the amount of phosphorus in the wastewater was reduced by more than 80 per cent, when the amount of iron fed into the process was 10 milligrams per litre," commented researcher Sakari Toivakainen, who is currently preparing his doctoral dissertation.

Simultaneous precipitation creates savings in wastewater treatment costs

Public authorities are calling for the lowering of phosphorus emissions. For this reason, many factories have adopted an additional post-treatment precipitation stage, which is usually implemented using aluminium.

"Post-treatment precipitation using aluminium produces difficult-to-process sludge. On the whole, simultaneous precipitation would seem to be a more advantageous option," Timo Laukkanen, Doctor of Science (Technology), concludes.

Simultaneous precipitation does not require additional wastewater treatment units, so there is no need for additional energy in the treatment of the water, either. An additional benefit of the method is that iron sulphate is an inexpensive chemical. A municipal wastewater treatment plant in Saint Petersburg constructed a few years ago employs simultaneous precipitation, among other methods. The industry, on the other hand, is only just waking up to the possibility of applying simultaneous precipitation. Wastewater from the forestry industry contains less phosphorus than municipal wastewater, so the dosage of the iron chemical remains within reasonable limits.

Experiments at the pulp mill

Initially, the research was carried out in the laboratories of Otaniemi and at the plant using pilot equipment. The results were so promising that, later on; iron precipitation was also successfully tested at the wastewater treatment section of a pulp mill.

"From the viewpoint of comprehensive environmental protection and sustainable development, the best method is always the one that saves energy and minimises the amount of waste. With the help of the studied simultaneous precipitation method, it is possible to completely avoid additional stages of wastewater treatment, reduce the amount of solid waste and save energy. Simultaneous precipitation produces hundreds of thousands of euros worth of savings in operating costs, as energy consumption and the need for additional chemicals is reduced," Professor Olli Dahl crystallises.


Story Source:

The above story is based on materials provided by Aalto University. Note: Materials may be edited for content and length.


Cite This Page:

Aalto University. "Simple way to precipitate phosphorus from the wastewater of a pulp mill." ScienceDaily. ScienceDaily, 21 November 2012. <www.sciencedaily.com/releases/2012/11/121121075758.htm>.
Aalto University. (2012, November 21). Simple way to precipitate phosphorus from the wastewater of a pulp mill. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2012/11/121121075758.htm
Aalto University. "Simple way to precipitate phosphorus from the wastewater of a pulp mill." ScienceDaily. www.sciencedaily.com/releases/2012/11/121121075758.htm (accessed October 31, 2014).

Share This



More Earth & Climate News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How A Chorus Led Scientists To A New Frog Species

How A Chorus Led Scientists To A New Frog Species

Newsy (Oct. 30, 2014) A frog noticed by a conservationist on New York's Staten Island has been confirmed as a new species after extensive study and genetic testing. Video provided by Newsy
Powered by NewsLook.com
Raw: Hawaii Lava Approaching Village Road

Raw: Hawaii Lava Approaching Village Road

AP (Oct. 30, 2014) The lava flow on the Big Island of Hawaii was 225 yards from Pahoa Village Road on Wednesday night. The lava is slowing down but still approaching the village. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Endangered Carpathian Ponies Are Making a Comeback in Poland

Endangered Carpathian Ponies Are Making a Comeback in Poland

AFP (Oct. 29, 2014) At the foot of the rugged Carpathian mountains near the Polish-Ukrainian border, ranchers and scientists are trying to protect the Carpathian pony, known as the Hucul in Polish. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Deadly Mudslide in Sri Lanka Buries Houses

Deadly Mudslide in Sri Lanka Buries Houses

AP (Oct. 29, 2014) A mudslide triggered by monsoon rains buried scores of workers' houses at a tea plantation in central Sri Lanka on Wednesday, killing at least 10 people and leaving more than 250 missing, an official said. (Oct. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins