Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


The retention of transition metals


The aim of this PhD is to study the retention of transition metals by humic substances. Transition metals are essential for life but, depending on their concentration in the environment, they can prove to be toxic and provoke serious environmental impact.

Humic substances are, on the other hand, macromolecules arising from the physical, chemical and microbiological transformation (humification) of biomolecules, explains Álvarez Puebla. Their importance is fundamental as they make up the most widespread an ubiquitous source of non-living organic material that nature knows. Approximately 80% of the total carbon in terrestrial media and 60% of the carbon dissolved in aquatic media are made up of humic substances.

Beyond their relevance for life, these substances have industrial applications for making absorbents of metal-poisoned sources. Being natural substances, their purification process is cheaper than the synthesis of any other absorbent and, moreover, due to their high operability, they absorb more than the absorbents used to date such as active charcoals or clays.

Mechanisms of retention

Humic substances have a great capacity for retaining transition metals, forming metalorganic complexes which cause these metals to be more or less available for plants and the plants pas to animals and these to humans.

Thus, Álvarez Puebla proposed a study of how the retention mechanisms operate in order to find out both the capacity and strength of retention a specific humic substance might have; i.e. how this metal-humic substance complex behaves after being subjected to different conditions.

To this end, copper, nickel and cobalt were chosen as all three are in the First Transition Series, are consecutive, are necessary for life, are quite common in industrial effluents, are very used and are very well parameterised for study by means of computer techniques.

Mathematical model for analysis

Álvarez Puebla drew up a mathematical model which enabled an interpretation of the interaction between metals and humic substances. This model considers the global process retention as a series of simple processes and, according to the author, provides good results and reveals a considerable selectivity of humic substances in order to retain the various metallic species as a function of pH and, to a lesser extent, of the concentration of the metal species in the solution.

Also, the theses held by other researchers, which have even been used as a basis for a United States legislative bill, argue that the transition metals may be liberated in alkaline soil, given that an insoluble hydroxide is formed which stays retained in the soil.

However, Álvarez Puebla has shown that humic substances, present in all soils, can mobilise the metal in question because they co-ordinate with it and make it soluble. On the metal mobilising with rain or river water, it can reach subterranean waters and return to the food chain, contaminating the environment.

All this research has been carried out both at a macroscopic level and a microscopic one, by means of various analysis techniques and mathematical and molecular modelling. In this way, the mechanisms of interaction of Co(II), Ni(II) and Cu(II) have been determined in a humic substance complex and its fractions, as a function of the metal concentration and pH of the medium.

Contact :
Iñaki Casado Redin
Nafarroako Unibertsitate Publikoa
(+34) 948 16 97 82

Iñaki Casado Redin | Basque research
Further information:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>