scholarly journals AN EXPERIMENTAL STUDY FOR THE CHARACTERIZATION OF BIOGAS PRODUCTION FROM COW DUNG AND DROPPINGS

2019 ◽  
pp. 54-61 ◽  
Author(s):  
Younoussa Moussa Baldé ◽  
Cellou Kanté ◽  
Sette Diop ◽  
Sihem Tebbani

The present work is an account of an ongoing work on biogas production from animal wastes at LEREA (Laboratoire d’enseignement et de recherche en énergétique appliquée) in Mamou, Guinea. The work consists of biogas production from anaerobic digestion and co-digestion of cow dung and droppings. We focus in this report on the determination of the physico-chemical characteristics of the experimental setup. We have carried out three experiments of anaerobic digestion each one lasting 45 days at mesophilic temperature (temperature was maintained in the range 27°C - 28°C). Biogas - 28.4 liters have been obtained from droppings, 22.6 liters from cow dung and 38.7 liters from co-digestion of the previous two wastes. The following physico-chemical characteristcs were observed for cow dung: humidity 43%, dry matter 20.83%, organic matter 57%, density 625kg/m3, carbon content 31%, nitrogen content 1.46%, nitrogen-carbon ratio 21/30. For droppings we measured: humidity 35%, dry matter 65%, organic matter 62%, density 250 kg/m3, carbon content 36%, nitrogen level 1.83%. This characterization was carried out on a sample of 3 g of each type of substrate. These results agree with those of the literature that we were able to compare with. Keywords: anaerobic digestion; anaerobic co-digestion; physico-chimical characterization; cow dung weste; droppings weste; methanation; animal waste

2015 ◽  
Vol 787 ◽  
pp. 803-808 ◽  
Author(s):  
A. Deepanraj ◽  
S. Vijayalakshmi ◽  
J. Ranjitha

The present research paper describes about the anaerobic digestion of vegetable (Banana, Cauliflower, potato, and sweet potato) and flower wastes (Rose, sambangi, gulmohar, marigold, golden shower tree, silk tree mimosa) in a 1L capacity of anaerobic digestor using pig manure as an inoculums. The digester was operated in the ratio of 1:1 of substrate to inoculums at RT. The substrate concentrations are varied such as 5%, 7%, and 10% was used and amount of gas produced was analysed using digital pressure gauge. The results obtained showed that, marigold flower had given higher yield of biogas than vegetable wastes and the digestion period was less. The average biogas production potential of withered flowers was observed as 14.36 g/kg in 5 days, where in case of vegetable wastes it was 10.0234 g/kg in 6 days. The study showed that flowers which are available in abundant in India is thrown away within a day, in the environment. These feedstocks are good feed stock for the production of biogas. The generation of biogas from flowers and vegetable waste upholds the concept of waste to wealth in enhancing sustainability of development. The future research work is mainly focused on the characterization of the main component present in the bio-gas using sophisticated instruments.


2016 ◽  
Vol 257 ◽  
pp. 147-151 ◽  
Author(s):  
Yi Wang ◽  
Svilen Bobev

Single-crystals of the new compound Ca14NbxIn1–xAs11 have been obtained from a solid-state reaction in a sealed Nb ampoule. The initial experiment had been set up with the aim to investigate the effect of electron doping (via In) on the crystal structure and physical properties of Ca14MnAs11. Subsequent single-crystal X-ray diffraction and elemental analysis work suggested that instead of Ca14MnxIn1–xAs11, the major product of the reaction is the phase Ca14NbxIn1–xAs11. This supposition was corroborated when the title compound was synthesized from a reaction of Ca, In and As in a sealed Nb ampoule, proving that, 1) Mn metal is not included in the structure, and 2) that the inadvertent side reaction of As with the walls of the Nb container is the source of the niobium. The overall structure is isotypic with the tetragonal Ca14AlSb11 structure type (space group I41/acd), although some marked differences between the two must be noted. Current ongoing work is focused on the synthesis of phase pure polycrystalline samples and determination of the physical properties of this unusual transition metal Zintl phase.


2020 ◽  
pp. 0734242X2093961 ◽  
Author(s):  
Ning Du ◽  
Meng Li ◽  
Qian Zhang ◽  
Mihret Dananto Ulsido ◽  
Ruyi Xu ◽  
...  

The poorly controlled discharge of coffee husks in Ethiopia causes severe environmental pollution and is a waste of resources. The volatile solid and carbon content in coffee husks waste indicates that it is rich in organic matter and has huge potential to produce biogas. This study investigated the feasibility of coffee husks to produce biomass through anaerobic digestion, based on temperature, initial pH, inoculum/substrate (I/S) ratio and carbon/nitrogen (C/N) ratio. The study demonstrated that the maximum production of biogas and methane reached 3359.6 ml and 2127.30 ml, respectively, under the conditions of mesophilic temperature (35±1°C), an initial pH of 7, an I/S ratio of 0.75 and a C/N ratio of 30. Based on this result, the effects of trace elements (Fe2+, Ni2+, Co2+) on biogas production and methane content were also explored. Compared with the group with no addition of trace elements, the experiment adding trace elements had significant enhancement effects on the production of biogas and methane, in which Fe2+ played a leading role ( p<0.05). Fe2+ promoted the hydrolysis and acidification of coffee husks, resulting in the production of a series of intermediates such as volatile fatty acids and the other kinds of dissolved organic matter. Furthermore, the cooperation of Ni2+, Co2+ and Fe2+ enhanced the activity of the enzyme system in methanogens, promoting methane production. The results in this paper show that coffee husks have clear biogas potential through anaerobic digestion, and its effective utilization could fulfill the dual purpose of solid waste reclamation and local environmental protection in Ethiopia.


Author(s):  
M. Fernández ◽  
J.I. Carreto ◽  
J. Mora ◽  
A. Roux

The benthic system of the Golfo San Jorge was characterized from physico-chemical parameters based on samplings obtained during seasonal research cruises carried out on board the INIDEP vessels from springtime 1999 through wintertime 2000. Spatial and seasonal variations of temperature, salinity, density, oxygen content and chlorophyll-a in bottom water and concentration of total organic matter, total organic carbon, total nitrogen, chlorophyll-a and phaeopigments in sediments were analysed. The origin and nutritional value of the deposited organic matter were also assessed. The behaviour of the physico-chemical characteristics of the benthic habitat, studied applying statistical techniques, defined three sectors with particular characteristics and minimum seasonal variations: sector 1, the largest and deepest one, comprises the central area of the gulf and corresponds to a depositional environment; sector 2 comprises the areas next to the extremes of the gulf and corresponds to a flow or erosive environment; sector 3 includes the coastal area and south-east part of the gulf and belongs to a transitional environment.


2011 ◽  
Vol 697-698 ◽  
pp. 326-330 ◽  
Author(s):  
S.X. Zhou ◽  
Y.P. Dong ◽  
Y.L. Zhang

Microbial pretreatment was applied to enhance biogas production from corn stover through solid-state anaerobic digestion, but the price of microbial strains is high. The objective of this study was to find the effects on biogas production by the naturally microbial pretreatment method. The highest cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained in B group (the pretreated corn straws with cow dung), which was 19.6% higher than that of the untreated samples. The D group(the pretreated corn straws with the sludge)cumulative biogas yield for 60-day solid-state anaerobic digestion was obtained, which was 18.87% higher than that of the untreted samples. The biogas of D group increased to the range of 55%~60% methane content, while B group with the range of 75%~80%.The results indicated that the pretreated corn straws mixing cow manure can improve both the biogas production yield and the content of methane in CH4。


2014 ◽  
Vol 955-959 ◽  
pp. 2692-2696 ◽  
Author(s):  
Li Fan Liu ◽  
Yong Wei Liao ◽  
Jie Liang ◽  
Shu Ting Lai

The characteristics such as pH, dry matter, carbon concentration, the total solid and volatile solid of kitchen wastes produced by a canteen in Guangzhou were measured. The anaerobic digestion process performances were evaluated through the examination of operational conditions like activated sludge inoculation, temperature on SS, biogas production, COD concentration and pH in the reactor. When the proportion between kitchen wastes to seed sludge inoculation was 1:1, the biogas production reached the peak at 45 °C. The kitchen waste pH decreased at the first four days then increased adversely after 4 days digestion, but COD concentration showed the opposite variation.


2017 ◽  
Vol 35 (9) ◽  
pp. 967-977 ◽  
Author(s):  
Muzammil Anjum ◽  
Azeem Khalid ◽  
Samia Qadeer ◽  
Rashid Miandad

Catering waste and orange peel were co-digested using an anaerobic digestion process. Orange peel is difficult to degrade anaerobically due to the presence of antimicrobial agents such as limonene. The present study aimed to examine the feasibility of anaerobic co-digestion of catering waste with orange peel to provide the optimum nutrient balance with reduced inhibitory effects of orange peel. Batch experiments were conducted using catering waste as a potential substrate mixed in varying ratios (20–50%) with orange peel. Similar ratios were followed using green vegetable waste as co-substrate. The results showed that the highest organic matter degradation (49%) was achieved with co-digestion of catering waste and orange peel at a 50% mixing ratio (CF4). Similarly, the soluble chemical oxygen demand (sCOD) was increased by 51% and reached its maximum value (9040 mg l-1) due to conversion of organic matter from insoluble to soluble form. Biogas production was increased by 1.5 times in CF4 where accumulative biogas was 89.61 m3 t-1substrate compared with 57.35 m3 t-1substrate in the control after 80 days. The main reason behind the improved biogas production and degradation is the dilution of inhibitory factors (limonene), with subsequent provision of balanced nutrients in the co-digestion system. The tCOD of the final digestate was decreased by 79.9% in CF4, which was quite high as compared with 68.3% for the control. Overall, this study revealed that orange peel waste is a highly feasible co-substrate for anaerobic digestion with catering waste for enhanced biogas production.


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