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Biochar samples were obtained by hydro-pyrolysis (600-800°C) of spent algae material, remaining after extraction of the liquid substances from algae for biodiesel production. The pore structure of the obtained carbon was studied by nitrogen adsorption at -196°C. The most prospective algae biochar sample obtained is distinguished by moderate surface area of 490 m²/g, as well as considerable microporosity (0.15 cm³/g) and mesoporosity (0.13 cm³ /g). Pore size distribution show that the pores with size 1-3 nm prevail. Presence of oxygen functional groups with weak acid and basic nature was established on the carbon surface, due to significant O/C ratio in algae residue after biodiesel production. The results show that obtained carbon could be used as adsorbent for organic pollutants and metal ions. This investigation intends to find successful utilization of industrial waste after biodiesel production from algae, as well as aims to obtain valuable products – carbon adsorbents for water purification. [ABSTRACT FROM AUTHOR]

Magnesium-based materials are very attractive as hydrogen storage media, due to their high hydrogen absorption capacity (theoretically, 7.6 wt.% H2) and low price. Some drawbacks of these materials, like slow hydrogen sorption kinetics and high absorptiondesorption temperatures, can be overcome using different additives and high energy ball milling. In this study, the hydrogen sorption characteristics of the Mg-Ni-C composites, prepared by ball milling under Ar atmosphere, are investigated. Polyolefin wax (POW, a waste product of polyethylene production at low pressure) was submitted to pyrolysis and steam activation, in order to prepare nanoporous carbon CPOW, which is further used as additive in the preparation of MgH2-Ni composite. Structure, phase and surface composition of the starting compounds, and the sample before and after hydriding are determined by XRD and TEM. The maximum absorption capacity achieved for composite containing ACPOW, after 60 min of hydriding at 573 K, is 5.3 wt. %. The presence of the additives - Ni and nanoporous carbon - has positive influence on both hydrogenation kinetics and the capacity achieved. The results from TEM characterization show the presence of graphite, Mg and monoclinic Mg2NiH4. [ABSTRACT FROM AUTHOR]

Adsorption of p-nitrophenol from aqueous solution by combined membrane-adsorption technology was studied. Activated carbon samples were synthesized on the base of industrial by products (coal tar pitch) and biomass. Synthetic activated carbon synthesized from mixture of coal tar pitch and furfural by thermo-oxidation treatment with sulfuric acid at 200oC, and subsequent carbonization in nitrogen atmosphere at 600 oC, followed by hydro-carbonyzation at 800oC. Biomass based activated carbon was obtained by hydro-carbonization of apricot stones at 800oC. Copolymer solutions were prepared by copolymer dissolution in DMSO. Activated carbon powder is added and the solutions were homogenized. The suspensions are cast on a glass and immersed in isopropyl alcohol - water mixture to form membranes. Five different membranes were synthesized from copolymer (acrylonitrile-vinyl acetate), and two types of activated carbon (synthetic and biomass based) in different amounts were added. It was established that the removal of p-nitrophenol varies from 9.2 to 29.73% depending on the type of membranes. Additional removal of the pollutant remaining in water was achieved after subsequent adsorption with synthetic activated carbon, which allows us to achieve up to 98.9% pollutant removal. [ABSTRACT FROM AUTHOR]

The aim of this study is to develop methods for obtaining carbon foams of various pore structure and high mechanical strength using polyethylene wax (by-products in polyethylene production) as raw materials. Characteristics of the foams consisted in the determination of the structure, morphology, density, thermal, mechanical and other properties of obtained carbon materials. The relation between physical and chemical properties of obtained carbon materials and conditions of their production was determined. [ABSTRACT FROM AUTHOR]