The contribution of dissolved organic matter (DOM) released from phytoplankton (Microcystis aeruginosa) during cultivation and biodegradation was examined to clarify the causes of the organic pollution of Lake Biwa. Two peaks, peak 2 (retention time (RT) = 32 min) and peak 3 (RT = 35 min), were detected in the algal DOM released from Microcystis aeruginosa during cultivation and biodegradation ...

Abstract Purpose The aims of the study were to investigate interaction between fractions organic matter and polycyclic aromatic hydrocarbons (PAHs) in bottom sediments use mussels as passive biomonitors consensus-based sediment quality guidelines for ecological risk assessment sediments. Methods Bottom samples taken from 46 points located Ro?nów reservoir (Poland). (SOM) characteristics include...

The aim of this work is to explore the suitability of the complementary use of mass spectra and the corresponding statistical analysis (principal components-Pareto analysis (PCA) and discriminant analysis (DA)) of these spectra to differentiate diverse humic samples as a function of their structural and conformational features. To this end, the mass spectra of humic samples belonging to the mai...

Iron deficiency, which severely decreases the plant yield and quality, is one of major problems calcareous soils. Foliar applications humic substances and/or Fe fertilizers are environmentally friendly methods to cope with deficiency. The aim this study was investigate combined effect Fe/nano humic/fulvic acid-based biostimulant foliar on content growth parameters spinach. Treatment solutions w...

Estudos do comportamento morfológico dos ácidos fúlvicos foram realizados utilizando a técnica de microscopia de força atômica aliada às técnicas de potencial zeta e espectroscopia de fluorescência. Os resultados mostraram que o ácido fúlvico (AFA) de um rio tropical mudou a sua morfologia quando variado o pH da solução aquosa dos AFA. Em pH ácido a morfologia é mais granular formando aglomerad...

Full structural characterization of complex mixtures such as humic acid extracts has been elusive because of insufficient compound resolution with conventional techniques. Using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry, we were able to resolve individual compounds within humic and fulvic acid mixtures (mass resolving power approximately 80...

The aggregation of 12 nm citrate-stabilized gold nanoparticles (cit-AuNPs) in the presence of four different natural organic matter (NOM) isolates and a monovalent electrolyte (KCl) was evaluated using time-resolved dynamic light scattering. All four NOM isolates stabilized the cit-AuNPs with respect to aggregation. However, specific effects varied among the different NOM isolates. At pH = 6 in...