Excitation−emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved organic matter (DOM) in water and soil. However, interpreting the >10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quantitative technique that integrates the volume beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation−emission regions based on fluorescence of model compounds, DOM fractions, and marine waters or freshwaters. Volumetric integration under the EEM within each region, normalized to the projected excitation−emission area within that region and dissolved organic carbon concentration, resulted in a normalized region-specific EEM volume (Φi,n). Solid-state carbon nuclear magnetic resonance (13C NMR), Fourier transform infrared (FTIR) analysis, ultraviolet−visible absorption spectra, and EEMs were obtained for standard Suwannee River fulvic acid and 15 h...

Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter.

Biochar as a sorbent for contaminant management in soil and water: a review.

Characterization of marine and terrestrial DOM in seawater using excitation-emission matrix spectroscopy

Climate change 2014 - Synthesis Report

Rapid turnover of organic matter leads to a low efficiency of organic fertilizers applied to increase and sequester C in soils of the humid tropics. Charcoal was reported to be responsible for high soil organic matter contents and soil fertility of anthropogenic soils (Terra Preta) found in central Amazonia. Therefore, we reviewed the available information about the physical and chemical properties of charcoal as affected by different combustion procedures, and the effects of its application in agricultural fields on nutrient retention and crop production. Higher nutrient retention and nutrient availability were found after charcoal additions to soil, related to higher exchange capacity, surface area and direct nutrient additions. Higher charring temperatures generally improved exchange properties and surface area of the charcoal. Additionally, charcoal is relatively recalcitrant and can therefore be used as a long-term sink for atmospheric CO2. Several aspects of a charcoal management system remain unclear, such as the role of microorganisms in oxidizing charcoal surfaces and releasing nutrients and the possibilities to improve charcoal properties during production under field conditions. Several research needs were identified, such as field testing of charcoal production in tropical agroecosystems, the investigation of surface properties of the carbonized materials in the soil environment, and the evaluation of the agronomic and economic effectiveness of soil management with charcoal.

http://www.css.cornell.edu/faculty/lehmann/publ/BiolFertSoils%2035,%20219-230,%202002%20Glaser.pdf

Ameliorating physical and chemical properties of highly weathered soils in the tropics with charcoal – a review

Electron spin resonance (ESR) spectrometry was used to study Cu(II) complexes with anionic surfactant compounds of the types that have been detected in sewage sludge or in the fulvic acid fraction of anaerobically-digested sewage sludge and found to resist biodegradation in the soil environment. The ESR spectra of frozen (77 °K), aqueous solutions of linear alkyl benzene sulfonates and fatty alcohol sulfate esters at Cu-ligand molar ratios ranging from 0.1 to 1 exhibited anisotropic patterns indicative of a d

 x
 
2−y

 2
 groundstate of Cu(II) bound into innersphere complexes with the ligands arranged in square planar coordination. Sulfonate-type surfactants, both in the acid and salt forms, appeared to complex Cu(II) more efficiently than ester sulfate-type surfactants. Conventional physical parameters calculated from the ESR spectra were consistent with fully oxygenated, 4 O-ligand binding sites for the Cu(II) ions and indicated the formation of similar unidentate or bidentate complexes between Cu(II) and the surfactants at any Cu/ligand molar ratio investigated. The spectral lineshapes and related parameters of the Cu(II)-anionic surfactant complexes, however, were not very similar to those observed previously for Cu(II)-sewage sludge FA complexes. It was concluded that anionic surfactants involved in Cu(II) complexation by sewage sludge or sewage sludge fulvic acid do not behave as isolated, independent ligands, but instead may participate as co-ligands with other O-containing functional groups and/or as moities incorporated into the fulvic acid structure.

Copper(II) complexes with refractory anionic surfactants found in sewage sludge

Adsorption of the herbicide triallate has been measured onto four different sandy soils and a pig‐slurry sample using a slurry‐type procedure. Adsorption data best fitted a linear model for two soils and the pig slurry, whereas a non linear Freundlich L‐type (1/n < 1) isotherm was the best fit for the two other soils. In general, adsorption of triallate appeared to be related to soil organic matter content, and to be much greater onto the pig slurry than on any soil considered. The low‐humified, highly aliphatic organic matter of the pig slurry would favour triallate adsorption, possibly by facilitating hydrophobic binding mechanisms.

Adsorption of triallate onto sandy soils and pig slurry

A fractal approach for interactions between soil particles and microorganisms.

Anticlastogenic and Antitoxic Actions Exerted by Humic Substances in Seedlings of Various Plants

Leaching of fenamiphos and its thiooxidation products, sulfoxide and sulfone, has been studied in two different soils in laboratory conditions. Fenamiphos was much less mobile than its derivatives. A large volume of water was necessary to leach completely the three chemicals. Fenamiphos required an amount of water twice as large as that required by either sulfoxide or sulfone. Mobility and leaching efficiency of the chemicals examined were highly dependent on the properties of the two soils considered.

Nicola Senesi

Papers

Copper(II) complexes with refractory anionic surfactants found in sewage sludge

Adsorption of triallate onto sandy soils and pig slurry

A fractal approach for interactions between soil particles and microorganisms.

Anticlastogenic and Antitoxic Actions Exerted by Humic Substances in Seedlings of Various Plants

Leaching of fenamiphos, fenamiphos sulfoxide and fenamiphos sulfone in soil columns