| 1. |
- Mukesh Kumar, Awasthi, et al.
(författare)
-
A critical review of organic manure biorefinery models toward sustainable circular bioeconomy: Technological challenges, advancements, innovations, and future perspectives
- 2019
-
Ingår i: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; , s. 115-131
-
Tidskriftsartikel (refereegranskat)abstract
- Total livestock emissions account for up to 14.5% of man-made greenhouse gas emissions. Counteractive measures, such as circular economy concepts and negative emission technologies are necessary to limit global warming below 1.5 °C. Possible treatment options for organic manure include anaerobic digestion, combustion, gasification, hydrothermal liquefaction and composting. The choice of treatment varies depending on the economics, the requirement of a specific product, and sociocultural factors. Commercialization of these treatments needs a blend of appropriate technology, feasible economics, policy support and agreeable socio-cultural conditions. Key findings of this study include the following: 1. Increasing scientific awareness about manure management and treatment; 2. Building a sustainable cooperative model to commercialize technologies; 3. Creating a market for manure recycling products; 4. The role of policy in supporting technologies and consumers; and 5. The codigestion of substrates for better efficacy. Current trends show minimal actions in place as opposed to the high-rate of acceleration that is necessary.
|
|
| 2. |
- Duan, Y., et al.
(författare)
-
Dynamics of fungal diversity and interactions with environmental elements in response to wheat straw biochar amended poultry manure composting
- 2019
-
Ingår i: Bioresource Technology. - : Elsevier Ltd. - 0960-8524 .- 1873-2976. ; , s. 410-417
-
Tidskriftsartikel (refereegranskat)abstract
- The fungal dynamics and its correlation with physicochemical and gaseous emission were investigated using metagenomics and Heat map illustrator (HEMI). Five different concentrations of wheat straw biochar (WSB) were applied to poultry manure (PM) and composted for 50 days; those without the WSB treatment were used as a control. The results revealed the dominant phyla to be Chytridiomycota, Mucoromycota, Ascomycota and Basidiomycota, while Batrachochytrium, Rhizophagus, Mucor, and Puccinia were the superior genera. In particular, the diversity of Chytridiomycota and Ascomycota was more abundant among all of the treatments. Overall, the diversity of the fungal species was correspondent, but relative abundance varied significantly among all of the composts. Principle Coordinate Analysis (PCoA) and Non-Metric Multi- Dimensional Scaling (NMDS) indicated that different concentrations of WSB applied treatments have significantly distinct fungal communities. In addition, correlation analyses of fungal interactions with environmental elements via HEMI also indicate a clear difference among the treatments. Ultimately, the relative abundance of fungal composition significantly influenced the PM compost treated by the WSB.
|
|
| 3. |
- Wainaina, Steven, et al.
(författare)
-
Bioengineering of anaerobic digestion for volatile fatty acids, hydrogen or methane production: A critical review
- 2019
-
Ingår i: Bioengineered. - : Taylor & Francis Group. - 2165-5979 .- 2165-5987.
-
Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion (AD) is a well-established technology used for producing biogas or biomethane alongside the slurry used as biofertilizer. However, using a variety of wastes and residuals as substrate and mixed cultures in the bioreactor makes AD as one of the most complicated biochemical processes employing hydrolytic, acidogenic, hydrogen-producing, acetate-forming bacteria as well as acetoclastic and hydrogenoclastic methanogens. Hydrogen and volatile fatty acids (VFAs) including acetic, propionic, isobutyric, butyric, isovaleric, valeric and caproic acid and other carboxylic acids such as succinic and lactic acids are formed as intermediate products. As these acids are important precursors for various industries as mixed or purified chemicals, the AD process can be bioengineered to produce VFAs alongside hydrogen and therefore biogas plants can become biorefineries. The current critical review paper provides the theory and means to produce and accumulate VFAs and hydrogen, inhibit their conversion to methane and to extract them as the final products. The effects of pretreatment, pH, temperature, hydraulic retention time (HRT), organic loading rate (OLR), chemical methane inhibitions, and heat shocking of the inoculum on VFAs accumulation, hydrogen production, VFAs composition, and the microbial community were discussed. Furthermore, this paper highlights the possible techniques for recovery of VFAs from the fermentation media in order to minimize product inhibition as well as to supply the carboxylates for downstream procedures.
|
|
