Fernández-Martínez M., Margalef O., Sayol F., Asensio D., Bagaria G., Corbera J., Sabater F., Domene X., Preece C. (2019) Sea spray influences water chemical composition of Mediterranean semi-natural springs. Catena. 173: 414-423.EnllaçDoi: 10.1016/j.catena.2018.10.035
Sea spray aerosol (SSA) is responsible for the large-scale transfer of particles from the sea to the land, leading to significant deposition of a range of ions, predominantly Na+, K+, Mg2+ Ca2+, and Cl−. Up to now, there has been little research into the effects of SSA on spring water chemistry. Therefore, we sampled 303 semi-natural springs across Catalonia (NE Iberian Peninsula) and analysed the concentrations of 20 different ions and elements, and determined the impact of SSA (using distance to the coast as a proxy) as well as climate, lithology and human disturbances. We found that distance to the coast had a clear effect on the water chemical composition of springs, while accounting for potentially confounding factors such as anthropogenic water pollution (nitrate, NO3 −), differences in lithology and annual rainfall. Our results showed that springs located closer to the coast had higher Cl−, SO4 2−, Na+, Mg2+, K+ and Ca2+ concentrations than those of springs located further away. Precipitation was generally negatively correlated with the concentration of almost all elements analysed. The concentration of NO3 − increased with distance to the coast, concurrently with farming activities, located mainly inland in the study area. These results demonstrate that SSA has an important effect on the groundwater of coastal zones, up to a distance of around 70 km from the coastline. This analysis reveals the main natural and human processes that influence spring water chemistry in this Mediterranean region, information that could be helpful in similar regions for ecological studies, water quality policies, and for the improvement of predictions in the current context of global change. © 2018 Elsevier B.V.
Zhao J.J., Shen X.-J., Domene X., Alcañiz J.-M., Liao X., Palet C. (2019) Comparison of biochars derived from different types of feedstock and their potential for heavy metal removal in multiple-metal solutions. Scientific Reports. 9: 0-0.EnllaçDoi: 10.1038/s41598-019-46234-4
Three different types of feedstocks and their biochars were used to remove Cr(III), Cd(II), Cu(II) and Pb(II) ions from a mixture of multiple heavy metals. The effect of the initial concentration of heavy metals in solution has been analysed, and kinetics modelling and a comparison of the adsorption capacity of such materials have been performed to elucidate the possible adsorption mechanisms. The results show that the adsorption capacity is dependent on the type of feedstock and on the pyrolysis conditions. The adsorption capacity of the biomass types is ranked as follows: FO (from sewage sludge)>> LO > ZO (both from agriculture biomass waste)>> CO (from wood biomass waste). Biochars, which are the product of the pyrolysis of feedstocks, clearly improve the adsorption efficiency in the case of those derived from wood and agricultural biomasses. Complexation and cation exchange have been found to be the two main adsorption mechanisms in systems containing multiple heavy metals, with cation exchange being the most significant. The pore structure of biomass/biochar cannot be neglected when investigating the adsorption mechanism of each material. All the disposal biomasses presented here are good alternatives for heavy metal removal from wastewaters. © 2019, The Author(s).
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