scholarly journals Evaluation of Hydrogen Sulfide Scrubbing Systems for Anaerobic Digesters on Two U.S. Dairy Farms

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4605 ◽  
Author(s):  
Abhinav Choudhury ◽  
Timothy Shelford ◽  
Gary Felton ◽  
Curt Gooch ◽  
Stephanie Lansing
Keyword(s):  
Hydrogen Sulfide ◽  
Iron Oxide ◽  
Dairy Farms ◽  
Trace Gas ◽  
Steel Wool ◽  
Anaerobic Digesters ◽  
Iron And Steel ◽  
Significant Difference ◽  
O2 Concentration ◽  
Scrap Iron

Hydrogen sulfide (H2S) is a corrosive trace gas present in biogas produced from anaerobic digestion systems that should be removed to reduce engine-generator set maintenance costs. This study was conducted to provide a more complete understanding of two H2S scrubbers in terms of efficiency, operational and maintenance parameters, capital and operational costs, and the effect of scrubber management on sustained H2S reduction potential. For this work, biogas H2S, CO2, O2, and CH4 concentrations were quantified for two existing H2S scrubbing systems (iron-oxide scrubber, and biological oxidation using air injection) located on two rural dairy farms. In the micro-aerated digester, the variability in biogas H2S concentration (average: 1938 ± 65 ppm) correlated with the O2 concentration (average: 0.030 ± 0.004%). For the iron-oxide scrubber, there was no significant difference in the H2S concentrations in the pre-scrubbed (450 ± 42 ppm) and post-scrubbed (430 ± 41 ppm) biogas due to the use of scrap iron and steel wool instead of proprietary iron oxide-based adsorbents often used for biogas desulfurization. Even though the capital and operating costs for the two scrubbing systems were low (<$1500/year), the lack of dedicated operators led to inefficient performance for the two scrubbing systems.

Programmed Iron Oxide Nanoparticles Disintegration in Anaerobic Digesters Boosts Biogas Production

Small ◽  
2014 ◽  
Vol 10 (14) ◽  
pp. 2801-2808 ◽  
Author(s):  
Eudald Casals ◽  
Raquel Barrena ◽  
Ana García ◽  
Edgar González ◽  
Lucía Delgado ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Biogas Production ◽  
Oxide Nanoparticles ◽  
Anaerobic Digesters

Occurrence of aflatoxin M1 in bovine milk and associated risk factors among dairy farms of Punjab, India

2021 ◽  
pp. 1-10
Author(s):  
H. Thukral ◽  
P. Dhaka ◽  
J. Singh Bedi ◽  
R. Singh Aulakh
Keyword(s):  
Risk Factors ◽  
European Union ◽  
Bovine Milk ◽  
Dairy Farms ◽  
Buffalo Milk ◽  
Cow Milk ◽  
Milk Samples ◽  
Significant Difference ◽  
Associated Risk Factors ◽  
Mean Concentration

Aflatoxin M1 (AFM1) contamination in milk and milk products may pose a major public health concern. The present cross-sectional study was aimed to estimate the prevalence of AFM1 in bovine milk across all districts of Punjab, India and to identify the associated animal and farm level risk factors. A total of 402 milk samples (266 cow milk and 136 buffalo milk) were analysed using commercial ELISA and representative samples were confirmed using HPLC-FLD. The results revealed that 56.2 and 13.4% of the milk samples exceeded the maximum levels of the European Union, i.e. 0.05 μg/l and Food Safety and Standards Authority of India (FSSAI), i.e. 0.5 μg/l for AFM1 in milk, respectively. On analysis of species variation, buffalo milk (prevalence: 56.6%; mean concentration: 0.42±0.9 μg/l) was found to have higher AFM1 levels than cow milk (prevalence: 56.0%; mean concentration: 0.19±0.3 μg/l), with statistically significant difference between mean concentrations (P<0.01) and non-significant difference between AFM1 prevalence (P=0.91). Furthermore, milk from commercial dairy farms (prevalence: 64.7%; mean concentration: 0.34±0.65 μg/l) was found to be more contaminated than from household dairy establishments (prevalence: 47.8%; mean concentration: 0.19±0.65 μg/l). The risk factors ‘above average milk yield/day’ (odds ratio (OR): 2.4) and ‘poor animal hygiene’ (OR: 1.9) were identified at animal level, and ‘intensive dairy farming’ (OR: 3.1) and ‘animal feed without aflatoxin binder’ (OR: 4.7) as farm level risk factors for AFM1 excretion above maximum levels of European Union in milk. Among cow breeds, the milk from ‘non-descript’ breed (OR: 11.5) was found to be most contaminated with AFM1 and the least from Jersey breed (OR: 1.0). The present study highlighted the presence of AFM1 in milk samples; therefore, regular monitoring of AFM1 in milk is required so that high risk regions and associated risk factors can be addressed appropriately.

Selective oxidation of hydrogen sulfide to elemental sulfur using iron oxide catalysts on various supports

1993 ◽  
Vol 17 (1-2) ◽  
pp. 217-224 ◽  
Author(s):  
R.J.A.M. Terörde ◽  
P.J. van den Brink ◽  
L.M. Visser ◽  
A.J. van Dillen ◽  
J.W. Geus
Keyword(s):  
Hydrogen Sulfide ◽  
Iron Oxide ◽  
Selective Oxidation ◽  
Elemental Sulfur ◽  
Oxide Catalysts ◽  
Oxidation Of Hydrogen

scholarly journals Comparison of Defined Course Doses (DCDvet) for Blanket and Selective Antimicrobial Dry Cow Therapy on Conventional and Organic Farms

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 707 ◽  
Author(s):  
Clair Firth ◽  
Annemarie Käsbohrer ◽  
Christa Egger-Danner ◽  
Klemens Fuchs ◽  
Beate Pinior ◽  
...  
Keyword(s):  
Animal Health ◽  
Dairy Farms ◽  
Point Of View ◽  
Antimicrobial Use ◽  
Organic Farms ◽  
Controversial Subject ◽  
Dry Cow Therapy ◽  
Significant Difference ◽  
History Of ◽  
The Difference

Antimicrobial use in livestock production is a controversial subject. While antimicrobials should be used as little as possible, it is still necessary, from both an animal health and welfare point of view, to treat infected animals. The study presented here aimed to analyse antimicrobial use on Austrian dairy farms by calculating the number of Defined Course Doses (DCDvet) administered per cow and year for dry cow therapy. Antimicrobial use was analysed by production system and whether farmers stated that they used blanket dry cow therapy (i.e., all cows in the herd were treated) or selective dry cow therapy (i.e., only cows with a positive bacteriological culture or current/recent history of udder disease were treated). A statistically significant difference (p < 0.001) was determined between antimicrobial use for blanket (median DCDvet/cow/year: 0.88) and selective dry cow therapy (median DCDvet/cow/year: 0.41). The difference between antimicrobial use on conventional and organic farms for dry cow therapy as a whole, however, was not statistically significant (p = 0.22) (median DCDvet/cow/year: 0.68 for conventional; 0.53 for organic farms). This analysis demonstrates that selective dry cow therapy leads to a lower overall use of antimicrobials and can assist in a more prudent use of antimicrobials on dairy farms.

scholarly journals Hydrogen sulfide-mediated cardioprotection against ischemia reperfusion is linked to KATP channel for mitochondrial preservation but not for its distinct preference on interfibrillar mitochondria

2019 ◽  
Vol 14 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Priyadharshini Chandrasekaran ◽  
Sriram Ravindran ◽  
Sri Rahavi Boovarahan ◽  
Gino A. Kurian
Keyword(s):  
Hydrogen Sulfide ◽  
Reperfusion Injury ◽  
Katp Channel ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Rat Hearts ◽  
Significant Difference ◽  
Interfibrillar Mitochondria ◽  
Subsarcolemmal Mitochondria

Hydrogen sulfide has been shown to protect  myocardium against ischemia-reperfusion injury by preserving interfibrillar mitochondria functional activi-ties than subsarcolemmal mitochondria. In this study, the role of the KATP channel in modulating the mitochondrial subpopulations during the cardioprotection mediated by NaSH (H2S donor) was investigated. Isolated rat hearts were treated with mitochondrial KATP channel closer glibenclamide (10 μM)/opener diazoxide (0.8 mM) via Langendorff perfusion apparatus before ischemia-reperfusion. The results showed that NaSH pre-conditioning in presence of glibenclamide significantly improved cardiac recovery without any significant difference between interfibrillar mitochondria and subsarcolemmal mitochondria.  In conclusion, targeting KATP channel may not be good option to target interfibrillar mitochondria/subsarcolemmal mitochondria against ischemia-reperfusion injury.

233. Oxygen concentration during in vitro maturation of murine oocytes affects blastocyst cell lineage

2005 ◽  
Vol 17 (9) ◽  
pp. 91
Author(s):  
K. M. Banwell ◽  
M. Lane ◽  
D. L. Russell ◽  
K. L. Kind ◽  
J. G. Thompson
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Cell Lineage ◽  
Developmental Competence ◽  
Embryo Viability ◽  
Blastocyst Development ◽  
Treatment Groups ◽  
Significant Difference ◽  
O2 Concentration

Follicular antral oxygen tension is thought to influence subsequent oocyte developmental competence. Despite this, in vitro maturation (IVM) is routinely performed in either 5 or 20% O2 and while low O2 has been shown to be beneficial to embryo development in many species, the effect of altering O2 concentration during IVM has not been adequately investigated. Here we investigated the effects of a range of O2 concentrations during IVM on meiotic maturation and subsequent embryo development after IVF. Ovaries from eCG-stimulated CBA F1 female mice (21 days) were collected and intact cumulus oocyte complexes (COCs) cultured for 17–18 h under 2, 5, 10 or 20% O2 (6% CO2 and balance of N2). Matured COCs were denuded of cumulus cells, fixed and stained (1% aceto-orcein) for visualisation of maturation status. No significant difference in maturation rates between treatment groups was observed. Following IVF (performed under 5% O2, 6% CO2 and balance of N2), no difference in fertilisation rates between treatment groups was observed in a randomly selected cohort 7 h post-fertilisation. There was also no significant difference in cleavage rates after 24 h or ability to reach blastocyst stage after 96 h, with a tendency (P = 0.079) for more blastocysts in 2% O2. However there was a significant increase in the number of trophectoderm cells present in the resulting blastocysts (P < 0.05) in the 2% O2 group (35 ± 2.1) compared to 20% O2 (25 ± 2.8). Our data suggests that O2 concentration during IVM does not influence nuclear maturation or subsequent fertilisation, cleavage and blastocyst development rates. However, maturation in 2% O2 significantly alters subsequent cell lineage within blastocysts to favour trophectoderm development. Such skewed trophectoderm cell number may influence embryo viability. Funded by NHMRC and NIH.

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