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 Faba fix for corn's nitrogen need
11.04.2018 | American Society of Agronomy

nachricht Wheat research discovery yields genetic secrets that could shape future crops
09.04.2018 | John Innes Centre

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: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

One step closer to reality

20.04.2018 | Life Sciences

The dark side of cichlid fish: from cannibal to caregiver

20.04.2018 | Life Sciences

Diamond-like carbon is formed differently to what was believed -- machine learning enables development of new model

19.04.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>