Soil and water microorganisms play an important role in maintaining ecosystem environmental quality. In fact, the ability of soil and water to recover from chemical contamination is primarily dependent on the presence of a microbial community with the ability to remove it. In this way, the microbial community represents an important key to understanding the impacts of environmental and anthropogenic factors on ecosystems. The presence of an abundant and varied microbial community is a necessary prerequisite for an immediate and effective response to the various natural and anthropic disturbances that can affect an ecosystem. Soil and water microcosm studies enable the studying, under controlled conditions, of the effects of selective pressures, such as xenobiotic occurrence on natural microbial communities. In this paper the main data (in terms of chemical persistence and bacterial abundance) of several microcosm degradation studies performed using natural soil and water were collected and discussed. The biotic and abiotic degradation of several contaminants (including the parent compounds of pesticides and pharmaceuticals and their metabolites) was evaluated comparing microbiologically active microcosms treated with the chemical with others previously sterilized. Moreover, in some cases additional microcosms were also used for evaluating the effect of some amendments (such as urea or wood amendments) on microbial degradation. The disappearance time of 50% of the compound applied (DT50) was evaluated for each chemical in the presence/absence of the natural microbial community in 19 microcosm experiments, performed using 16 different chemicals considered environmental contaminants. The overall results presented here show the key role of microorganisms in the degradation of all the chemicals studied and establish the relationship between degradation and the role of microbial communities in chemical disappearance from the environment, thus demonstrating the suitability of the of the microcosm approach for reproducing more realistic environmental exposure scenarios in the laboratory.
► Biodegradation of the herbicides and pharmaceuticals selected was shown both in soil and water ► Microcosm studies make it possible to evaluate the natural attenuation of contaminants in soil and water ► Laboratory microcosms are a good compromise between field experiments and standard laboratory tests ► We suggest performing microcosm studies conducted under different natural conditions in order to reproduce more realistic scenarios of environmental exposure to chemicals
Paola Grenni, Anna Barra Caracciolo, Paola Bottoni
Publication date: July 2013Source:Journal of Solid State Chemistry, Volume 203 Author(s): S. Kumar , K. Singh , M. Miclau , Ch. Simon , C. Martin , A. Maignan The change from antiferromagnetism induced ferroelectricity to spin glass ferroelectric relaxor has been studied along the ... more
Publication date: July 2013Source:Journal of Solid State Chemistry, Volume 203 Author(s): Brian B. Kitchen , Nina Verdal , Terrence J. Udovic , John J. Rush , Michael R. Hartman , Daniel J. DeVries To investigate the previously reported low-temperature phase transition in rubidium ... more
Publication date: July 2013Source:Journal of Solid State Chemistry, Volume 203 Author(s): T. Sasikala , L. Rama Moorthy , A. Mohan Babu , T. Srinivasa Rao The present work reports the absorption, photoluminescence and decay properties of singly doped Dy3+ and co-doped Dy3+/Tm3+ ions ... more
Elsevier announced the acquisition through its subsidiary MDL Information Systems GmbH, of the Beilstein Database, the world's largest compilation of chemical facts and the premier database in the field of organic chemistry.
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