Concentrations of CO2 from composting under different treatments

I. Karandušovská¹, P. Hlinka², D. Páleš³ and T. Szabóová¹

¹Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of Building Equipment and Technology Safety, Tr.A. Hlinku 2, SK94976 Nitra, Slovakia
²Local Union of Ponitrie villages for separation and management of waste, Korytovská 20, SK95141 Lužianky, Slovakia
³Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of Machine Design, Tr.A. Hlinku 2, SK 94976 Nitra, Slovakia
*Correspondence: ingrid.karandusovska@uniag.sk

Abstract:

The aim of this study was to analyse the production of CO2 concentrations in relation to the composting technology used. Three loose piles of bio-waste (V1, V2, V3) were created with the same volume. V1 reference pile was without any treatment. The biological preparation containing probiotic bacteria was added to the pile V2. The pile V3 was treated once a week by turning and watering. The degassing shafts were installed in each pile and the Multigas Monitor 1312 gas analyser with the Multipoint Sampler 1309 were used to measure of gas concentrations during the degradation process. Continuous 24-hour measurements of carbon dioxide concentrations from each pile were performed in the first, fourth, and seventh week of the degradation process to compare the amount of concentrations between piles in those weeks. At the beginning of the process, there were no significant differences in the production of CO2 concentrations from the monitored piles V1, V2 and V3. In the fourth week, significantly higher values of CO2 concentrations were recorded from the pile V3 (P < 0.05), which was turned and irrigated, than from V1 and V2. At week 7, significant differences were found between all treatments at the significance level (P < 0.05), with the highest values from the V3 pile. It has been shown that turning and humidifying results in the highest release of CO2 into the air, but in a more rapid decomposition of the microorganisms, that reducing the time required to achieve a stable compost product and increasing the efficiency of the composting plant.

Key words:

carbon dioxide in compost, compost moisture, compost properties, composting technology, environmental impacts.

Environmental consequences of anaerobic digestion of manure with different co-substrates to produce bioenergy: A review of life cycle assessments

S. Pehme* and E. Veromann

Estonian University of Life Sciences, Kreutzwaldi 1, EE51014 Tartu, Estonia; *Correspondence: sirli.pehme@emu.ee

Abstract:

Consequential life cycle assessment approach is needed to assess the environmental impacts of increase in biogas production. To see the full impacts of anaerobic co-digestion all possible environmental consequences caused by this change, i.e. the impacts of changed management and possible substitution impacts of substrates, should be taken into account. Generally anaerobic digestion of manure shows great environmental benefit instead of managing it conventionally, especially for the global warming potential. Environmental performance of co-digestion depends strongly on the initial use of the substrate. Co-digestion with wastes/residues has a great potential to produce bioenergy and reduce global warming potential. Co-digestion with land dependant special energy crops increases the bioenergy output but also increases the environmental impacts due to the need to substitute the substrate and thus should be avoided or limited.

Key words: