Search results for "Cow dung"
showing 10 items of 11 documents
Effects of temperature on post-methanation of digested dairy cow manure in a farm-scale biogas production system.
2003
A post-methanation process that could be adopted at farm-scale, operating at temperatures prevailing in farm manure digester post-storage tanks, was evaluated. Digested manure samples from a farm digester (35 degrees C) and post-storage tank (5-10 degrees C) were incubated in parallel batches at 5-20 degrees C and as reference at 35 and 55 degrees C. Specific methane yields (kg(-1) volatile solids (VS)(added waste)) were 0.20-0.26 m3 at 35-55 degrees C and 0.085-0.09 m3 at 10-20 degrees C for digester material (345 days of incubation) and 0.16-0.21 m3 at 35-55 degrees C, 0.053-0.087 kg(-1) VS(added waste) m3 at 15-20 degrees C and 0.026 m3 at 10 degrees C for post-storage tank material (250…
Biogas from energy crops--optimal pre-treatments and storage, co-digestion and energy balance in boreal conditions.
2008
The objective of this research was to evaluate the biogas production from crops in boreal conditions, focusing on the optimal pre-treatment and storage methods, co-digestion and energy balance of farm-scale crop based biogas plants. Alkaline treatments offered some potential for improving the methane yield from grass and sugar beet tops. The results show that the CH4 yield of energy crops can be maintained by appropriate ensiling conditions for even after 11 months in ambient conditions. The CH4 yield was best preserved with wet grass mixture without additives. Co-digestion of manure and crops was shown to be feasible with feedstock volatile solids (VS) containing up to 40% of crops. The hi…
Impact of crop species on bacterial community structure during anaerobic co-digestion of crops and cow manure
2008
The bacterial communities in three continuously stirred tank reactors co-digesting cow manure with grass silage, oat straw, and sugar beet tops, respectively, were investigated by 16S rRNA gene-based fingerprints and clone libraries. The analyses revealed both clearly distinct and similar phylotypes in the bacterial communities between the reactors. The major groups represented in the three reactors were Clostridia, unclassified Bacteria, and Bacteroidetes. Phylotypes affiliated with Bacilli or Deltaproteobacteria were unique to the sugar beet and straw reactor, respectively. Unclassified Bacteria dominated in sugar beet reactor while in the straw and grass reactor Clostridia was the domina…
Zinc removal in anaerobic sulphate-reducing liquid substrate process
2002
Abstract Zinc and sulphate removal from synthetic wastewater was investigated by using four laboratory parallel upflow-mode reactors (referred as R1 to R4; R1 contained carriers to retain biomass, whereas R2–R4 were operated as suspended reactors). All reactors were inoculated with anaerobically digested cow manure. R1 and R2 were first fed with glucose- and sulphate-containing feed for 48 days after which all four reactors were fed with wastewater containing 50 mg l−1 of zinc in R1–R3 and 200 mg l−1 in R4 and operated for 96 days. In all reactors, hydraulic retention time, organic loading rate, and sulphate load were 5–6 d, 0.2–0.4 kg COD m−3 d−1 and 3.3–3.8 g SO4 l−1 d−1, respectively, wh…
Laboratory investigations on co-digestion of energy crops and crop residues with cow manure for methane production: Effect of crop to manure ratio
2007
Abstract Anaerobic co-digestion of grass silage, sugar beet tops and oat straw with cow manure was evaluated in semi-continuously fed laboratory continuously stirred tank reactors (CSTRs). Co-digestion of manure and crops was shown to be feasible with feedstock volatile solids (VS) containing up to 40% of crops. The highest specific methane yields of 268, 229 and 213 l CH4 kg−1 VSadded in co-digestion of cow manure with grass, sugar beet tops and straw, respectively, were obtained with 30% of crop in the feedstock, corresponding to 85–105% of the methane potential in the substrates as determined by batch assays. Including 30% of crop in the feedstock increased methane production per digeste…
Effects of solid–liquid separation on recovering residual methane and nitrogen from digested dairy cow manure
2006
The feasibility of optimizing methane and nitrogen recovery of samples obtained from farm biogas digester (35 degrees C) and post-storage tank (where digested material is stored for 9-12 months) was studied by separating the materials into different fractions using 2, 1, 0.5 and 0.25 mm sieves. Mass-balances revealed that digested material mainly consists of0.25 mm (60-69%) and2 mm (18-27%) fractions, while fractions between 2 and 0.2 mm made the rest. Incubation of solid fractions0.25 mm of digester material at 35 degrees C resulted in specific methane yields of 0.060-0.085 m(3)kg(-1) volatile solids (VS) during initial 30-50 d and 0.16-0.18 m(3)kg(-1)VS at the end of 340 d incubation. Sim…
Screening of novel plants for biogas production in northern conditions.
2013
Abstract The objective of this study was to screen nine annual or perennial novel plants for biogas production cultivated in years 2007–2010 in Finland. The most promising novel plants for biogas production were found to be brown knapweed, giant goldenrod and Japanese millet producing 14–27 t total solids/ha and 4000–6100 Nm 3 CH 4 /ha. The specific methane yields of all studied plants varied from 170 to 381 Nm 3 CH 4 /t volatile solids (VS), depending on harvest time and plant species. Co-digestion of brown knapweed with cow manure in continuously stirred tank reactor was investigated and the highest methane yield was 254 NL CH 4 /kg VS, when the share of brown knapweed was 50% in the fe…
Co-digestion of energy crops and industrial confectionery by-products with cow manure: batch-scale and farm-scale evaluation.
2002
The possible co-digestion of energy crops and industrial confectionery by-products with cow manure was evaluated firstly, through long-term batch experiments and secondly, in a farm-scale digester. In batch assays, digestion with mesophilically digested cow manure as inoculum resulted in specific methane yields (m3 kg−1 VSadded waste) of 0.35 for grass hay (particle size <1.0 cm); 0.26 for oats (0.5 cm) and 0.21 for clover (2.0 cm) harvested at vegetative stage and 0.14 (2.0 cm) for clover harvested at flowering stage. Specific methane yields (m3 kg−1 VSadded waste) for confectionery by-products were 0.37 for chocolate, 0.39 for black candy and 0.32 for confectionery raw material. Ou…
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…
Bioindicators and nutrient availability through whole soil profile under orange groves after long-term different organic fertilizations
2019
We investigated long-term (18 years) effects of three organic (cow manure (CM), poultry manure (PM), compost from agro-industry orange wastes (OW)) and one inorganic fertilization (IF) on various soil biological indicators (microbial biomass C, soil respiration, total phospholipid fatty acids (PLFAs), total bacteria, Gram-positive and Gram-negative bacteria and fungi) and nutrient contents (total and extractable organic C, total and mineral N, available P and K) along the profile of a Typic Haplustept under orange Mediterranean orchards. All fertilizers were added on the same N content basis (190 kg N ha−1 per year). Variables related to carbon cycling gradually worsened with depth, regardl…