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Fossil carbon-containing fuel is currently one of the most common in industry and economy. The rapid depletion of reserves of this fuel makes it necessary to search for the alternative one. Landfills are a place where methane is spontaneously synthesized due to the decay of organic waste. Controlled and regulated fermentation of the landfill organics can provide biomethane as well as environmental bioremediation. The aim of the work was to study the patterns of methane fermentation of multi component organic waste and optimize the process to increase the efficiency of biomethane synthesis and waste decomposition. Colorimetric and potentiometric methods were used for pH and Eh measurement. Volumetric and chromatographic methods were applied to control volume and composition of synthesized gas. Fermentation parameters were calculated with the use of mathematical and statistical ones. The achievement of high efficiency of methane fermentation of organic waste due to the process regulation was shown. The modeling of unregulated fermentation of organic waste in landfills showed low efficiency of the process. It took 69 days. Weight of waste decreased only 5 times. Hydrogen yield was 5 L/kg of waste. Methane was not synthesized. The regular mass transfer, regulation of the process and waste grinding showed the greatest efficiency. Weight of waste decreased 20 times during only 14 days. Hydrogen yield was 27 L/kg, methane yield was 12 L/kg of waste. Thus, the absence of regulation caused long term decay of waste. The high efficiency is achieved due to regulation of the fermentation process. The results will serve as a basis for the development of industrial biotechnology for the utilization of organic waste to reduce the volume of existing landfills and produce methane energy. This will further allow bioremediation of contaminated areas, obtaining an alternative to fossil fuel biomethane.

Environmental pollution by toxic metals is a common ecological problem. Chromium and copper compounds released into the environment as a result of human-made stress pose a serious threat to living organisms. Phytoremediation is a promising method of toxic metals removal from contaminated sites. The concentration of metals in grass biomass—in the roots and aerial parts—was determined by X-ray fluorescence analysis. The estimation of numbers of microorganisms was conducted by a tenfold dilution and spread-plating method. It was shown that lawn grass accumulated from 69.1 ± 13.2 to 497.7 ± 74.1 mg/kg Cu and Cr during the growth in the contaminated soil with 50, 100, and 200 mg/kg of metals. In general, there was a pattern of accumulation of copper in the aerial part of the grass and chromium in the roots. Thus, the total copper concentration in the aerial part ranged from 105.2 ± 23.8 to 497.7 ± 74.1 mg/kg of plant biomass. The total chromium concentration in the roots ranged from 156.4 ± 47.9 to 426.8 ± 62.5 mg/kg. The viability of the soil microbiome was not inhibited at such metal concentrations. The obtained data allow lawn grass to be considered as promising for the phytoremediation of contaminated areas.