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Using biogas instead of fossil fuels decreases pollutants such as solid particles, sulphur dioxide, nitrogen oxides concentrations in the environment. Green energy and development of relevant infrastructure improves air quality considerably. Chemical, physical, biological methods are used for biogas purification. The main difficulties using biological methods are selection of suitable microorganisms' suspensions and making optimal conditions in photobioreactor. Different origin and structure microalgae suspensions are used applying biological treatment methods. Monoraphidium griffithi, which is widespread in fresh water, has relatively high potential. Microalgae’ cultures absorb the main components of biogas - carbon dioxide (CO2) and hydrogen sulphide (H2S). Absorbtion processes are based on photosynthesis. Microalgae absorb specific components of biogas when there are suitable light source and nutrient solvent. The main purposes of the research are to asses emission of biogas using different substrates (chicken manure and wastewater sludge). Also, it was measured main physical and chemical characteristics of both substrates: acidicy, temperature, redox potential, conductivity, biohemical oxygen demand. According results of the research, emission from wastewater sludge is greater than from chicken manure so sludge was chosen in teh next stage of the research. The next stage - asssessment of purification efficienty using Monoraphidium grifftihii suspension. Raw biogas was supplied to photobioreacor (with microalgae suspension). Alterations of methane, carbon dioxide, oxygen, hydrogen sulphide concentrations were measured precisely. According to results concentration of methane in the beginning of the researc was 62%, after 35 days - 69%. Meanwhile carbon dioxide - 37% and 31% by analogy. Experimental research alows to assess Monoraphidium griffithi absorption capacity of ballast components. Results were compared to different scientists' results which were present in scientific journals and publications. Comparative analysis alows to assess practical possibilities to use Monoraphidium griffithi as biological treatment of raw biogas. [ABSTRACT FROM AUTHOR]

Volatile organic compounds, e. g. acetone, have a direct impact on climate change, decrease of ozone in the air, and on the growth of greenhouse effect. One of the most popular air purifying methods from VOC is a biological air cleaning. Experimental investigations were conducted to determine the efficiency of the new structure of biofilter with polypropylene plates segments. During the investigations the efficiency of segmental construction biofilter of air purification at different initial concentrations of pollutants was determined. Different concentrations of pollutants were estimated during the acetone dilution with water. During the tests the efficiency of biofilter air purification from acetone vapor and its change under different concentrations of vapors was set. Based on test results, the maximum efficiency of biofilter air purification was up to 93%. Studies have shown that increasing the allowable pollutant concentration, the efficiency of air purification unit decreases. Increasing the concentration of supplied acetone vapor into the biofilter from 232 to 701 mg/m3, cleaning efficiency decreased from 92.8 to 82.3%. Since microorganisms fail to oxidize organic compounds, the filter works better at lower initial concentrations of pollutants. [ABSTRACT FROM AUTHOR]

Experimental studies have been carried out using an adsorber - a constructed laboratory bench. Zeolite, a natural mineral, has been selected as a charge. This aluminosilicate of a crystalline structure is resistant to high temperatures, aggressive mediums and the impact of radiation. Zeolite is ecologically clean, inert and non-toxic material, which fully suits to be used in most industrial, agricultural, environment fields and at home for eliminating the consequences of ecological accidents etc. For the purification of contaminated biogas, the laboratory adsorber is equipped with three sections filled up with 10 cm of adsorbing material the efficiency of which is established after every filtration column (10 cm, 20 cm and 30 cm). The studies have been carried employing two different contaminants - sulphur hydrogen (H2S) and ammonia (NH3). It has been established that, with a high concentration of sulphur hydrogen, the efficiency has amounted to 96.1% while the degree of ammonia purification has reached 95.4%,when NH3 concentration in biogas is 24.0 mg/m³. [ABSTRACT FROM AUTHOR]

Air cleaning efficiency tests on placing material load into the lavsan biofilter were carried out. Testing included butanol vapour-contaminated air stream pulled during the boot. The studies were conducted by the Department of Environmental Protection at VGTU that developed a biofilter - an experimental biological air cleaning device. Measurements were done using 60 lmin and 90 lmin air volume aspirators under the initial pollutant concentration making 180,305, 350,440 and 545 mg/m³. Before measuring the concentrations of butanol lavsan cartridge, loading was periodically irrigated with nutrient-rich solution. In order to evaluate the influence of microorganisms on genus Pseudomonas, cleaning efficiency tests were repeated - Boot was moistened with water only, which allowed measuring butanol vapour concentrations after the cartridge. At the concentration of 180±9 mg/m³, efficiency reached 41% at a speed of 0,07 m/s and 46 % at a speed of 0,10 m/s. Measuring the performance of the initial concentration of 545±67 mg/m³, efficiency was 54% at 0,07 m/s and 53 % at 0,10 m/s respectively. [ABSTRACT FROM AUTHOR]

A four -- section trickle biofilter was constructed for experimental research. The filter was filled with the packing material of artificial origin. The material consists of plastic balls having a large surface area. The dependence of biofilter aerodynamic resistance on supply air flow rate and the number of filter sections was determined. The aerodynamic resistance of the biofilter was measured in two cases. In the first case, the packing material of the filter was dry, whereas in the second case it was wet. The experimental research determined that an increase in the air flow rate from 0.043 m/s to 0.076 m/s causes an increase in biofilter aerodynamic resistance from 30.5 to 62.5 Pa after measuring four layers of dry packing material. In case of wet packing material, biofilter aerodynamic resistance after measuring four layers of plastic balls increases from 42.1 to 90.4 Pa. [ABSTRACT FROM AUTHOR]