Freshwaters: which NOM matters?

Abstract

One of the difficulties encountered in the study of natural organic matter (NOM) in aquatic environments concerns terminology: a large number of different names and acronyms are used. In fact, this diversity merely reflects the variety of approaches applied to the study of NOM, leading to the definition and measurement of different operationally-defined fractions. As a result, the choice of the ‘best’ method to use and of the ‘best’ fraction to work on in a particular case is far from straightforward. This has as a consequence that often very simple methods for NOM characterisation are used in applied environmental studies and surveys. This study includes, first, a review of the most widely applied terminology, as described in over 500 articles, and, second, a first attempt at assessing how the panoply of methods available is really used in applied environmental studies

Long-term Trends of Organic Carbon Concentrations in Freshwaters: Strengths and Weaknesses of Existing Evidence

“…The surrogate parameters used such as color, absorbance, etc. only respond to a fraction of the organic matter present in the system, usually the fraction more refractory to degradation fraction, often known as humic substances [99,100]. Surprisingly, this fact is rarely acknowledged in the studies considered, with rare exceptions such as [29].…”

Solid-phase extraction-stepwise elution (SPE-SE) procedure for isolation of dissolved organic matter prior to ESI-FT-ICR-MS analysis

“…The constituents of DOM are extremely complicated and thus its molecular composition is still largely unknown, which poses a barrier to understanding the molecular mechanism of the interaction between DOM and environmental contaminants [6,7]. In the past decades, various techniques including spectroscopic, chromatographic and mass spectrometric methods have been established to investigate the composition and characteristics of DOM.…”

Impact of Powdered Activated Carbon Structural Properties on Removal of Organic Foulants in Combined Adsorption-Ultrafiltration

“…In aquatic chemistry, the term "NOM" is used to designate all organic material in an aqueous ecosystem other than living organism and compounds of anthropogenic origin [1]. NOM originates from degradation of aqueous and terrestrial plants as well as from microbial excretion.…”

“…Furthermore, it consists of both hydrophobic components, including mainly aromatic carbon, with phenolic structures and conjugated double bonds as well as hydrophilic fractions, containing higher portions of aliphatic carbon and nitrogenous compounds [2]. Note: 1 Dissolved organic carbon content of humic substance peaks determined by LC-OCD-UVD measurements using ChromCALC Software (DOC Labor Dr. Huber (Karlsruhe, BW, Germany)) for peak integration.…”