Abstract:The results of anaerobic digestion (AD) of buttermilk (BM) and cheese whey (CW) with a digested sewage sludge as inoculum is described. The substrate/inoculum mixtures were prepared using 10% buttermilk and 15% cheese whey. The essential parameters of the materials were described, including: total solids (TS), volatile solids (VS), pH, conductivity, C/N ratio (the quantitative ratio of organic carbon (C) to nitrogen (N)), alkalinity, chemical oxygen demand (COD). The potential directions of biodegradation of the organic waste types, as used in this study, are also presented. Appropriate chemical reactions illustrate the substrates and products in each phase of anaerobic decomposition of the compounds that are present in buttermilk and cheese whey: lactic acid, lactose, fat, and casein. Moreover, the biogas and biomethane production rates are compared for the substrates used in the experiment. The results have shown that buttermilk in AD generates more biogas

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A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM.

Multifunctional chitin/lignin materials were synthesized. In order to combine mechanical milling of the biopolymers with simultaneous mixing, a centrifugal ball mill was utilized. The resulting materials, differing in terms of the proportions of precursors used, underwent detailed physicochemical and dispersive-morphological analysis. On the basis of FT-IR spectra and results of elemental analysis, the efficiency of the preparation of the materials was determined. The influence of the precursors on the thermal stability of the resulting systems was also evaluated. Zeta potential was determined as a function of pH to describe the electrokinetic stability of aqueous dispersions. This is important for evaluating the utility of the materials and indirectly confirms the effectiveness of the proposed method of synthesis of chitin/lignin products. Measurements were performed to determine basic colorimetric parameters, crucial in the production technology of multiple colored materials. It is expected that chitin/lignin materials will find a wide range of applications (biosorbents, polymer fillers, and electrochemical sensors), as they combine the unique properties of chitin with the specific structural features of lignin to provide a multifunctional material.

The article describes a pilot study on a wastewater treatment plant operating a biogas plant (2.793 MW). The authors of the experiment used organic waste material, including: chicken fat with feathers (FF), molasses (M), glycerol (GL), raw sewage sludge (SS) and digested sewage sludge as an inoculum. The parameters of raw and digested sludge were compared, e.g. changes in the concentrations of ammonium nitrogen (N-NH4+), alkalinities, chemical oxygen demand (COD) and light metal ions. Potential biodegradation pathways for the organic waste used in the experiments were also proposed. The proposed sequences of chemical reactions are a useful tool for further biochemical analyses and for the mathematical modeling of anaerobic digestion. The results showed that fat with feathers was the most valuable high-energy substrate as it gave a cumulative methane yield of 822 m 3 /mg VS (VS-volatile solids). There were comparable values of cumulative methane yield from molasses (350 m 3 /mg VS) and glycerol (342 m 3 /mg VS), whereas sewage sludge gave the lowest yield (246 m 3 /mg VS).

The immobilization of Amano Lipase A fromAspergillus niger by adsorption onto Stöber silica matrix obtained by sol-gel method was studied. The effectiveness of the enzyme immobilization and thus the usefulness of the method was demonstrated by a number of physicochemical analysis techniques including Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TG), porous structure of the support and the products after immobilization from the enzyme solution with various concentration at different times. The analysis of the process' kinetics allowed the determination of the sorption parameters of the support and optimization of the process. The optimum initial concentration of the enzyme solution was found to be 5 mg mL -1 , while the optimum time of the immobilization was 120 minutes. These values of the variable parameters of the process were obtained by as ensuring the immobilization of the largest possible amount of the biocatalyst at the most economically beneficial aspects of the process.

Magnesium hydroxide was prepared under controlled conditions from aqueous Mg(NO 3 ) 2 and NaOH solutions. The small, nanoplate-shaped particle size distribution was monomodal from 164 to 459 nm. Functional polypropylene/Mg(OH) 2 and polypropylene/polypropylene 1% maleic anhydride/Mg(OH) 2 composites were prepared containing 10% or 30% Mg(OH) 2 . The composites have a high Young's modulus (twice that of polypropylene) and comparable tensile strength but less ductility. EDX examination of the fractured composite surfaces suggested a homogeneous Mg(OH) 2 distribution for composites produced with the addition of polypropylene grafted with maleic anhydride. The polypropylene/Mg(OH) 2 composites showed good antibacterial activity. The polypropylene/ polypropylene 1% maleic anhydride/Mg(OH) 2 composites were less effective.

The research reported here concerns the synthesis, characterization and potential applications of silica/lignosulfonate hybrid materials. Three types of silica were used (Aerosil®200, Syloid®244 and hydrated silica), along with magnesium lignosulfonate. The effectiveness of the hybrid material synthesis methodology was confirmed indirectly, using Fourier transform infrared spectroscopy, elemental and colorimetric analysis. Dispersive-morphological analysis indicates that the products with the best properties were obtained using 10 parts by weight of magnesium lignosulfonate per 100 parts of Syloid®244 silica. The relatively high thermal stability recorded for the majority of the synthesized products indicates the potential use of this kind of a material as a polymer filler. Results indicating the high electrokinetic stability of the materials are also of great importance. Additionally, the very good porous structure properties indicate the potential use of silica/lignosulfonate systems as biosorbents of hazardous metal ions and harmful organic compounds.