Search results for "Digestat"
showing 10 items of 28 documents
Effects of storage on characteristics and hygienic quality of digestates from four co-digestion concepts of manure and biowaste.
2007
This study evaluated the effects of storage in northern winter conditions (5 degrees C) on the characteristics and nutrients separation of digestates from co-digestion of manure and biowaste as well as the hygienic quality of the digestates after digestion and storage. During 3-11 months' storage average nitrogen losses and reductions of total solids (TS) and volatile solids (VS) were 0-15%. With some exceptions, soluble chemical oxygen demand (SCOD) had increased slightly (from approximately 6.5 to approximately 7.5g/l) after 3 months' storage, while after 9-11 months' it had decreased from 8.3-11 to 5.6-8.4g/l. The concentrations of P(tot) and PO4-P in the separated liquid fractions decre…
Biomethane production from maize and liquid cow manure – Effect of share of maize, post-methanation potential and digestate characteristics
2013
Abstract This study investigates the co-digestion of liquid cow manure and maize with different share of maize in continuously stirred tank reactors (CSTRs). The objective was to determine the methane yield of reactor and the post-methanation potential of the digestate from different reactor trials. The highest specific methane yield (259 Nl CH 4 /kg volatile solids (VSs)) was obtained when the share of maize in the feedstock was 40% (VS) and the second highest specific methane yield was when the proportion of maize was 60% (VS) (234 Nl CH 4 /kg VS). The post-methanation potential of the digestate was determined in batch assays. The minimum value (maize 40%, 75 ± 1 Nl CH 4 /kg VS feed ) occ…
Parte V - Utilizzazione agronomica ed impatto sul sistema suolo-pianta 15. Aspetti biologici
2022
In this chapter authors focused on how and why biochar, compost, sewage sludge and digestate deriving from waste biomasses affect soil biological activities.
Life Cycle Impact Assessment applied to cactus pear crop production for generating bioenergy and biofertiliser
2020
Among the potential uses of cactus pear, the generation of bioenergy (biogas) and biofertiliser (digestate), from the Anaerobic Digestion (AD) of cladodes and fruits, is surveyed in this paper. Data for Life Cycle Impact Assessment (LCIA) was drawn from a farm located in Roccapalumba (Palermo, Sicily, Italy), where three cultivars were cultivated: 1) yellow pulp cultivar; 2) red pulp cultivar; 3) white pulp cultivar. LCIA was applied to six scenarios: 1) current dry crop; 2) current irrigated crop; 3) dry crop for fruit and bioenergy production; 4) irrigated crop for fruit and bioenergy production; 5) dry crop for bioenergy production; 6) irrigated crop for bioenergy production. According t…
Effects of Vermicompost, Compost and Digestate as Commercial Alternative Peat-Based Substrates on Qualitative Parameters of Salvia officinalis
2021
Peat is a common substrate used for the cultivation of potted plants. However, the use of peat in horticulture has recently been questioned from an environmental standpoint, since it is a non-renewable resource and plays a major role in atmospheric CO2 sequestration. The aim of this work was to assess the potentialities of substrates obtained from vermicompost, compost and anaerobic digestion processes to partially substitute peat for sage (Salvia officinalis L.) cultivation. Therefore, we planned an experiment to assess the effect of these substrates on essential oil (EO) yield and composition, as well as on leaf nutrients concentration of sage plants. The three substrates were mixed with …
Carbon and nitrogen stabile isotope ratio and heavy metals in Leccinum aurantiacum in a hybrid aspen plantation in agricultural land
2020
Edible mycorrhizal fungi can be harvested in the fourth year after establishment of a hybrid aspen plantation in previous agricultural land at hemiboreal conditions. It is important to understand the role of fungi in element cycling at the ecosystem level as well as the amounts of elements, including heavy metals, that are accumulated in fruitbodies of edible fungi in the context of food safety. Therefore we evaluated the carbon and nitrogen stable isotope ratio and content of heavy metals (Cr, Pb, Mn, Ni, Cd, Cu and Zn) in Leccinum aurantiacum (Bull.) Gray in a juvenile hybrid aspen (Populus tremuloides Michx. × Populus tremula L.) plantation in agricultural land initially fertilised with …
Plants for Environmental Protection
2023
Plants for environmental protection are Anaerobic Digestion plants for converting biomass as Renewable Energy Source (RES), i.e. biowaste, agricultural feedstock, livestock effluents (manure and slurry) and food industry by-products, into biogas, i.e. bioenergy, as well as digestate, i.e. biofertiliser. In turn, biogas can be converted into electrical and thermal energy or can be used for extracting biomethane, i.e. biofuel, or can be injected in the natural gas grid. Moreover, digestate can be divided into solid and liquid fractions, that can be used for fertilisation or fertirrigation, respectively, sometimes after aerobic composting.
Sustainable, circular and innovative value chains using growing substrata alternative to peat for the cultivation of nutraceutical species
2019
The modern agricultural system is wasteful, with Europe generating some 700 million tonnes of agricultural and food waste each year. In the context of the agri-food chain, the ‘circular economy’ aims to reduce waste while also making best use of the ‘wastes’ produced by using economically viable processes and procedures to increase their value. In this paper we will try to frame the key issues associated with food waste into the emerging bioeconomy and circular-economic mode, suggesting that these three concepts are intertwined, and considering them unitarily might provide win-win solutions that minimize wastage, promote income growth and job creation, and prompt sustainable local developme…
Co-digestion of grass silage and cow manure in a CSTR by re-circulation of alkali treated solids of the digestate.
2008
Three laboratory, continuously stirred tank reactors (CSTRs) co-digesting grass silage and cow manure (forming 30% and 70% of substrate volatile solids (VS), respectively) were operated to evaluate the effects of re-circulating an alkali-treated and untreated solid fraction of the digestate back to the reactors. The CSTRs were operated at an organic loading rate (OLR) of 2 kg VS m(-3) day(-1) and hydraulic retention time (HRT) of 20 days with a semi-continuous mode of feeding. The feasibility of co-digestion with substrate VS containing 30% VS of crop was reinforced, resulting in average specific methane yield of about 180-185 1 CH4 kg(-1) VS. Re-circulation of the solid fraction of digesta…
Review of the impact of biogas digestates on the microbiological quality of agricultural soils
2023
The global production of biogas has increased threefold during the last decade to partly replace fossil fuels, yet biogas production by anaerobic digestion generates substantial amounts of by-products named digestates. These biogas digestates can be recycled in soils to fertilize crops and to sequester carbon. However, the impact of digestates on the soil biological is actually poorly known. Here we reviewed the impact of digestates published in 56 articles reporting 23 microbial parameters. Half of the articles show neutral effects of biogas digestates and 7% showed negative effects. 25% of the articles show more stimulation of biogas digestates for the soil microbial quality, compared to …