Author: Jared Verrill Goldstone
Publisher:
ISBN:
Category : Carbon cycle (Biogeochemistry)
Languages : en
Pages : 278

Get Book Here

Book Description
Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02- ) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.

Author: Rossana Del Vecchio
Publisher:
ISBN:
Category : Organic compounds
Languages : en
Pages : 482

Get Book Here

Book Description

Author: Kelly Jo Gordon
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 84

Get Book Here

Book Description

Author: Mary Beth Adams
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 94

Get Book Here

Book Description

Author: Seth Neil Reid
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 144

Get Book Here

Book Description

Author: E Walter Helbling
Publisher: Royal Society of Chemistry
ISBN: 1847552269
Category : Science
Languages : en
Pages : 600

Get Book Here

Book Description
This book offers extensive coverage of the most important aspects of UVR effects on all aquatic (not just freshwater and marine) ecosystems, encompassing UV physics, chemistry, biology and ecology. Comprehensive and up-to-date, UV Effects in Aquatic Organisms and Ecosystems aims to bridge the gap between environmental studies of UVR effects and the broader, traditional fields of ecology, oceanography and limnology. Adopting a synthetic approach, the different sections cover: the physical factors controlling UVR intensity in the atmosphere; the penetration and distribution of solar radiation in natural waters; the main photochemical process affecting natural and anthropogenic substances; and direct and indirect effects on organisms (from viruses, bacteria and algae to invertebrate and vertebrate consumers). Researchers and professionals in environmental chemistry, photochemistry, photobiology and cell and molecular biology will value this book, as will those looking at ozone depletion and global change.

Author: Emma J. Rochelle-Newall
Publisher:
ISBN:
Category : Carbon compounds
Languages : en
Pages : 368

Get Book Here

Book Description

Author: Angelo Albini
Publisher: Royal Society of Chemistry
ISBN: 1782626956
Category : Science
Languages : en
Pages : 398

Get Book Here

Book Description
Providing critical reviews of recent advances in photochemistry including organic and computational aspects, the latest volume in the Series reflects the current interests in this area. It also includes a series of highlights on molecular devices, global artificial photosynthesis, silicon nanoparticles, solar energy conversion, organic heterogeneous photocatalysis and photochemistry in surface-water environments. Volume 44 of the annual Specialist Periodical Reports: Photochemistry is essential reading for anyone wishing to keep up with the literature on photochemistry and its applications.

Author: Kevin R. Arrigo
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

Get Book Here

Book Description

Author: S.A. GREEN
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description