Long-term effects of amendment with liquid swine manure on proton binding behavior of soil humic substances

The acid-base properties of humic acids (HAs) and fulvic acids (FAs) isolated from liquid swine manure (LSM), soils amended with either 90 or 150 m(3)ha(-1)year(-1) of LSM for 7 years, and the corresponding unamended control soil were investigated by a current potentiometric titration method. The non-ideal competitive adsorption (NICA)-Donnan model for proton binding by two classes of binding sites (i.e., carboxylic- and phenolic-type groups) was fit to titration data, and a set of fitting parameters was obtained for each HA and FA sample. The NICA-Donnan model was shown to describe with a great degree of accuracy the behavior of experimental titration datasets, and highlighted important differences in the acid-base properties of the HAs and FAs examined. When compared to the unamended soil HA and FA, LSM-HA and LSM-FA, had smaller acidic functional group contents, larger proton binding affinities of both carboxylic- and phenolic-type groups, smaller heterogeneity of carboxylic-type groups, and smaller, in the case of HA, or similar, in the case of FA, heterogeneity of phenolic-type groups. Amendment with LSM caused a decrease of acidic functional group contents and a slight increase of proton binding affinities of carboxylic- and phenolic-type groups of soil HAs and FAs. Further, LSM application induced a decrease of the heterogeneity of carboxylic-type groups, whereas appeared not to affect substantially the heterogeneity of phenolic-type groups of LSM-amended soil HAs and FAs. These effects were more evident for HAs than for FAs and tended to slightly increase with increasing LSM amendment rate.     

Detection of copper(II) and zinc(II) binding to humic acids from pig slurry and amended soils by fluorescence spectroscopy

The effect of the consecutive annual additions of pig slurry at rates of 0 (control), 90 and 150 m3 ha(-1) yr(-1) after a 7-year period on the Cu(II) and Zn(II) binding behavior of soil HAs was investigated in a field experiment. A fluorescence titration method and a single site model were used for determining metal ion complexing capacities and stability constants of metal ion complexes of HAs isolated from pig slurry and unamended and amended soils. With respect to control soil HA, pig-slurry HA featured much smaller Cu(II) and Zn(II) binding capacities and stability constants. Pig-slurry application to soil decreased Cu(II) and Zn(II) complexing capacities and binding affinities of soil HA. These effects increased with increasing the rate per year of PS application to soil, and are expected to have a large impact on bioavailability, mobilization, and transport of Cu(II) and Zn(II) ions in pig slurry-amended soils.     

Polishing of painting process effluents through adsorption with biochar from winemaking residues

Environmental Science and Pollution Research - A real industrial effluent from the pre-treatment and painting processes was polished through adsorption using alternative biochar derived from grape...     

Old growth forests and large old trees as critical organisms connecting ecosystems and human health. A review

Old forests containing ancient trees are essential ecosystems for life on earth. Mechanisms that happen both deep in the root systems and in the highest canopies ensure the viability of our planet. Old forests fix large quantities of atmospheric CO₂, produce oxygen, create micro-climates and irreplaceable habitats, in sharp contrast to young forests and monoculture forests. The current intense logging activities induce rapid, adverse effects on our ecosystems and climate. Here we review large old trees with a focus on ecosystem preservation, climate issues, and therapeutic potential. We found that old forests continue to sequester carbon and fix nitrogen. Old trees control below-ground conditions that are essential for tree regeneration. Old forests create micro-climates that slow global warming and are irreplaceable habitats for many endangered species. Old trees produce phytochemicals with many biomedical properties. Old trees also host particular fungi with untapped medicinal potential, including the Agarikon, Fomitopsis officinalis, which is currently being tested against the coronavirus disease 2019 (COVID-19). Large old trees are an important part of our combined cultural heritage, providing people with aesthetic, symbolic, religious, and historical cues. Bringing their numerous environmental, oceanic, ecological, therapeutic, and socio-cultural benefits to the fore, and learning to appreciate old trees in a holistic manner could contribute to halting the worldwide decline of old-growth forests.

     

Monitoring of cyanobacteria and cyanotoxins in a Colombian tropical reservoir

Environmental Science and Pollution Research - Anthropogenic pollution and global climate change have resulted in favorable environmental conditions for increased frequency and duration of...