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•A greater degree of SGD was observed in the sandy compared to muddy sediments.•Element fluxes were higher in the muddy compared sandy impacted SGD sediments.•Benthic diagenesis processes impact the SGD composition.•SGD is a mixing between groundwater originating from different aquifers.

The human health and environmental risk assessment of engineered nanomaterials (NPs) is nowadays of high interest. It is important to assess and predict the biological activity, toxicity, physicochemical properties, fate and transport of NPs. In this work, a combined experimental and computational study is performed in order to estimate the toxicity and develop a predictive model for heterogeneous NPs (i.e.modified NPs, created from more than one type of NPs). Quantitative structure–activity relationship (QSAR) methods have not been yet adopted for predicting the toxicity/physicochemical properties of modified heterogeneous nanoparticles (so-called heterogeneous NPs). Since the main problem for nano-QSAR/nano-QSPR modeling of heterogeneous NPs was a lack of appropriate descriptors that are able to express the specific characteristics of 2nd generation NPs, we developed here a novel approach. The novel approach to encode heterogeneous NPs is based on the idea of additive descriptors for mixture systems previously applied only to mixtures of organic/inorganic compounds. Thus, based on the proposed novel approach, we have performed experimental and theoretical studies to develop nano-QSAR models describing the cytotoxicity of 34 TiO2-based NPs modified by (poly)metallic clusters (Au, Ag, Pt) to the Chinese hamster ovary cell line. The models showed a good predictive ability and robustness. This approach can be used as an efficient tool for assessing the toxicity as well as physicochemical properties of unexplored heterogeneous NPs.

The paper presents a short review of published results about different methods of waste glycerol conversion to the various chemicals and energy carriers as well the preliminary experimental results of the photocatalytic glycerol conversion into hydrogen. The first part of the paper presents literature data pertaining to the glycerol utilization, including thermal methods (incineration, pyrolysis, gasification and reforming), catalytic oxidation, chemical and biochemical conversion and photoconversion into hydrogen, are presented. The mechanism of selected processes and reaction conditions are also discussed. The second part of the paper presents the results of the hydrogen production over irradiated aqueous glycerol solution containing TiO2-based photocatalysts (TiO2-modified W, Mn, Cr, Ni, Co, Pt, Pd, Au and Ag). The test runs were performed in the batch and semi-batch reactors equipped with Xe lamps as a light source. Much higher hydrogen productivity was observed for the titania modified by noble metals than for transition metal used for modification. The highest hydrogen productivity (24.2 mmol H2·gcat-1·h-1) was reached in the presence of Pt/TiO2, when glycerol concentration in the solution equaled to 4.5 wt.% and the photocatalysts loading in the suspension was ~ 0.042 wt.%.

The paper presents a short review of published results about different methods of waste glycerol conversion to the various chemicals and energy carriers as well the preliminary experimental results of the photocatalytic glycerol conversion into hydrogen. The first part of the paper presents literature data pertaining to the glycerol utilization, including thermal methods (incineration, pyrolysis, gasification and reforming), catalytic oxidation, chemical and biochemical conversion and photoconversion into hydrogen, are presented. The mechanism of selected processes and reaction conditions are also discussed. The second part of the paper presents the results of the hydrogen production over irradiated aqueous glycerol solution containing TiO2-based photocatalysts (TiO2-modified W, Mn, Cr, Ni, Co, Pt, Pd, Au and Ag). The test runs were performed in the batch and semi-batch reactors equipped with Xe lamps as a light source. Much higher hydrogen productivity was observed for the titania modified by noble metals than for transition metal used for modification. The highest hydrogen productivity (24.2 mmol H2·gcat-1·h-1) was reached in the presence of Pt/TiO2, when glycerol concentration in the solution equaled to 4.5 wt.% and the photocatalysts loading in the suspension was ~ 0.042 wt.%.