Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Adding high doses of sludge to neutralise soil acidity not advisable

08.01.2009
A University of the Basque Country PhD thesis has analysed the application of waste sludge from EDAR (Estación Depuradora de Aguas Residuales - Waste Water Purification Plant) to acid soils which have limited capacity for neutralising the acidity.

Sludge obtained from water purification plants can be reused, as fertiliser for soils, for example or to reduce their acidity. The main aim of this University of the Basque Country (UPV/EHU) PhD research thesis was to study the effects of the application of EDAR (Estación Depuradora de Aguas Residuales - Waste Water Purification Plant) waste sludge on the chemical properties of the soil and on the water filtering through it — with special attention being paid to the behaviour of heavy metals. Moreover, the effects on forest plantations — concretely those of Pinus radiata —, have been studied.

The author of the thesis is Dr. Goio Egiarte Castañeira, who presented it with the title, Application of sewage sludge as amendment on acid forest soils. Effect on the soil-water system plan, with special attention to the behaviour of heavy metals. Dr Egiarte is an agricultural engineer currently working as a secondary school teacher. He undertook his PhD under the direction of Ms Estilita Ruiz Romera from the Department of Chemical and Environmental Engineering at the Higher School of Engineering of the UPV/EHU and Ms Marta Camps Arbestain from the Department of Agricultural Systems and Natural Resources at Neiker-Tecnalia.

When carrying out the research for the thesis, Dr. Egiarte had the help of the Dipartimento de Science Ambientali e delle Produzioni Vegetali at the Università Politecnica delle Marche in Ancona (Italy), of the Department of Pedology and Agricultural Chemistry at Biology Faculty of the University of Santiago de Compostela (Galicia) and the Bilbao Bizkaia Water Consortium.

Suitable dose

The study approach for the thesis was particularly innovative, not only for the possible use of fertilising sludge on forest soils, but also because it studied the effect of heavy metals and nitrogenated forms. To this end, experiments were carried out over a four-year period.

With the results obtained from these experiments, Dr. Egiarte has come to the conclusion that adding high doses of EDAR sludge is totally inadvisable, even when the sludge complies with current norms as regards levels of heavy metals. When the compounds of the sludge begin to oxidise, they produce acidity and, in order to reduce this acidity, an alkaline system is necessary. But the alkanility of the system created on uniting the sludge with the soil is not capable of neutralising the acidity generated.

On the other hand, the application of much lower doses of waste sludge — three times less —considerably reduces acidification of the soil and heavy metal content. Moreover, the production of forest biomass is very similar to that obtained by applying higher doses.

Nevertheless, Dr. Egiarte emphasises that the use of other types of sludge from waste water purification plants — with a greater capacity of neutralisation of acids and a greater stability of organic elements — on acid soils, such as the one studied, is much more recommendable.

Lucía Álvarez | alfa
Further information:
http://www.elhuyar.com
http://www.basqueresearch.com/berria_irakurri.asp?Berri_Kod=2016&hizk=I

More articles from Agricultural and Forestry Science:

nachricht Researchers discover a new link to fight billion-dollar threat to soybean production
14.02.2017 | University of Missouri-Columbia

nachricht Important to maintain a diversity of habitats in the sea
14.02.2017 | University of Gothenburg

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>