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.

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 23, 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 23, 2014).

Share This



More Earth & Climate News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
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