Stream biofilms are exposed to dynamic conditions of flow velocity and organic carbon availability. Thus, the aim of this study was to investigate the response of biofilms formed with and without humic substances (HSs) to an increase in flow velocity (0.04-0.10 ms(-1)) and HSs concentration (9.7+/-1.0 to 19.8+/-0.4 mgL(-1) C). The highest amount of biofilm, measured as volatile suspended solids...

Humate substances (HSs) are raw materials very easy to obtain and naturally occurring organic molecules found in soil due the humification of dead components. Traditionally used as conventional medicine China India fertilizer agriculture. Humic acids widely utilized feed additives could enhance ruminant performance. The effect humic acid on intake depends level supplementation, a source, experi...

Forensic crime scene sample analysis, by its nature, often deals with samples in which there are low amounts of nucleic acids, on substrates that often lead to inhibition of subsequent enzymatic reactions such as PCR amplification for STR profiling. Common substrates include denim from blue jeans, which yields indigo dye as a PCR inhibitor, and soil, which yields humic substances as inhibitors....

Characterization of humic substances (HS) in environmental samples generally involves labor-intensive and time-consuming isolation and purification procedures. In this paper, the development of an automated system for HS isolation and purification is described. The novelty of the developed system lies in the way the multiple liquids and columns used in the isolation/purification procedure are h...

Sammary-nree soil humic' aelds were degraded by a new mild chemical oxidatioo me!hod usiog potassium persulfate at pH 2.0. The melbod degraded 30-40"/0 of!he staning material. n. type and relative quantities of tbe products or fragments released as detennined by GC¡MS varíed with the source of lbe polymers. Humic aeld extracted from ao Inceptisol yielded fatty, benzenecarboxylic and pbenolic ae...

Amphiphilic molecules, such as humic substances and surfactants, are known to increase the apparent aqueous solubility of hydrophobic organic compounds (HOCs) in the aqueous phase because of their molecular structures, which consist of hydrophilic and hydrophobic moieties. In this study, we examined the effect of the structures of humic acid and HOCs on the sorption of four polycyclic aromatic ...

Humic substances, i.e. dark paramagnetic polymeric anionic polyelectrolytes, belong to the most widespread macromolecular substances of biogenic origin in soil and aquatic environments. The exact structure of humic substances is unknown because of their complexity resulting from unrecurring precursors, from their composition and their process of synthesis. Degradation processes of these substan...

Humic acids are amphiphilic species whose behavior in aqueous solution suggests that they form pseudomicellesÐaggregates akin to the micelles familiar from synthetic surfactant chemistry. It is thought that humic pseudomicelles can be formed by both intramolecular coiling and intermolecular association, depending on the molecular weight, structural characteristics, and polydispersity of the hum...