Unravelling the influence of cattle stocking rate on the macroinvertebrate community of freshwater wetlands subjected to hydrological modifications in three hydroclimatic periods.

The Paraná River Delta in South America, a large wetlands macromosaic, faces threats from climate change, human activities like livestock intensification, and hydrological modifications driven by the construction of water management infrastructure to prevent flooding in productive lands. Macroinvertebrates, essential for wetland health, are affected by cattle-induced changes in water quality, nutrient enrichment, and trampling, posing challenges to the ecosystem's ecological balance and long-term survival of these organisms. In this study, we analyzed the impact of two categories of cattle stocking rates (low and high) on the taxonomic and functional structure of the aquatic macroinvertebrate community in freshwater marshes.

ERIC-PCR technique applied to monitoring and quantification of DNA damage during water disinfection process.

In this work, we propose a novel application of ERIC-PCR technique to study DNA damage after ultraviolet radiation (UV) and peracetic acid (PAA) treatment for water disinfection purpose. The efficacy of both treatments on E. coli suspension was evaluated by two approaches: through monitoring of inactivation by conventional culture technique, and by analyzing DNA damage with ERIC-PCR.

Kinetic model of water disinfection using peracetic acid including synergistic effects.

The disinfection efficiencies of a commercial mixture of peracetic acid against Escherichia coli were studied in laboratory scale experiments. The joint and separate action of two disinfectant agents, hydrogen peroxide and peracetic acid, were evaluated in order to observe synergistic effects. A kinetic model for each component of the mixture and for the commercial mixture was proposed.

A novel approach to explain the inactivation mechanism of Escherichia coli employing a commercially available peracetic acid.

The chemical inactivation of Escherichia coli employing a commercial mixture of peracetic acid (PAA) was studied. For this purpose, experiments were carried out using dilutions of the unmodified mixture, and also the same mixture but altered with hydrogen peroxide (HP) previously inhibited. Also, these results were compared to those obtained before employing HP alone.

Water disinfection with UVC radiation and H2O2. A comparative study.

A generalized kinetic model resulting from several modifications of the one originally known as the Series Event Model has been applied to describe three different disinfection processes and compare their efficiencies. The work was performed in a well-defined, versatile batch reactor employing Escherichia coli as a subrogate bacteria. The following systems were studied: (i) UVC radiation alone, (ii) hydrogen peroxide alone and (iii) UVC radiation combined with hydrogen peroxide.

Dichloroacetic acid degradation employing hydrogen peroxide and UV radiation.

The degradation reaction of dichloroacetic acid employing H(2)O(2) and UVC radiation (253.7nm) has been studied in a well mixed reactor operating inside a recycling system. It has been shown that in an aqueous solution no stable reaction intermediates are formed and, at every time during the reaction, two mols of hydrochloric acid are formed for every mol of dichloroacetic acid that is decomposed and, in the same way, there is a paired agreement between the calculated TOC concentration corresponding to the unaltered dichloroacetic acid and the experimental values measured in the solution.