https://cyberleninka.org/article/n/1316165.pdf

Nanocellulose in biomedicine: Current status and future prospect

With the rising demand for renewable energy and environmental protection, anaerobic digestion of biogas technology has attracted considerable attention within the scientific community. This paper presents a comprehensive review of research achievements on anaerobic digestion developments for biogas production. The review includes a discussion of factors affecting efficiency (temperature, pH, C/N ratio, OLR and retention time), accelerants (greenery biomass, biological pure culture and inorganic additives), reactors (conventional anaerobic reactors, sludge retention reactors and anaerobic membrane reactors) and biogas AD processes (lignocellulose waste, municipal solid waste, food waste, livestock manure and waste activated sludge) based on substrate characteristics and discusses the application of each forementioned aspect. The factors affecting efficiency are crucial to anaerobic digestion, because they play a major role in biogas production and determine the metabolic conditions for microorganism growth. As an additive, an accelerant is not only regarded as a nutrient resource, but can also improve biodegradability. The focus of reactor design is the sufficient utilization of a substrate by changing the feeding method and enhancing the attachment to biomass. The optimal digestion process balances the optimal digest conditions with the cost-optimal input/output ratio. Additionally, establishment of theoretical and technological studies should emphasize practicality based on laboratory-scale experiments because further development of biogas plants would allow for a transition from household to medium- and large-scale projects; therefore, improving stability and efficiency are recommended for advancing AD research.

Review on research achievements of biogas from anaerobic digestion

Anaerobic digestion is a commercial reality for several kinds of waste. Nonetheless, anaerobic digestion of single substrates presents some drawbacks linked to substrate characteristics. Anaerobic co-digestion, the simultaneous digestion of two or more substrates, is a feasible option to overcome the drawbacks of mono-digestion and to improve plants economic feasibility. At present, since 50% of the publication has been published in the last two years, anaerobic co-digestion can be considered the most relevant topic within anaerobic digestion research. The aim of this paper is to present a review of the achievements and perspectives of anaerobic co-digestion within the period 2010-2013, which represents a continuation of the previous review made by the authors [3]. In the present review, the publications have been classified as for the main substrate, i.e., animal manures, sewage sludge and biowaste. Animal manures stand as the most reported substrate, agro-industrial waste and the organic fraction of the municipal solid waste being the most reported co-substrate. Special emphasis has been made to the effect of the co-digestion over digestate quality, since land application seems to be the best option for digestate recycling. Traditionally, anaerobic co-digestion between sewage sludge and the organic fraction of the municipal solid waste has been the most reported co-digestion mixture. However, between 2010 and 2013 the publications dealing with fats, oils and greases and algae as sludge co-substrate have increased. This is because both co-substrates can be obtained at the same wastewater treatment plant. In contrast, biowaste as a main substrate has not been as studied as manures or sewage sludge. Finally, three interdisciplinary sections have been written for addressing novelty aspects in anaerobic co-digestion, i.e., pre-treatments, microbial dynamics and modeling. However, much effort needs to be done in these later aspects to better understand and predict anaerobic co-digestion.

A critical review on anaerobic co-digestion achievements between 2010 and 2013

Recent advances in lactic acid production by microbial fermentation processes

A review on dark fermentative biohydrogen production from organic biomass: Process parameters and use of by-products

Biogas and CH4 productivity by co-digesting swine manure with three crop residues as an external carbon source.

States and challenges for high-value biohythane production from waste biomass by dark fermentation technology

Co-digesting swine manure with three agricultural residues, i.e., corn stalks, oat straw, and wheat straw, to enhance biogas productivity was investigated in this study. A 3 × 3 experimental design with duplicates was adopted (3 crop residues × 3 carbon/nitrogen ratios) to examine the improvement of batch digestion in terms of biogas volume produced, CH4 content in the biogas, and net CH4 volume. The crop residues were first cut into small sections and then ground into fine particles smaller than 40 mesh size (0.422 mm) before being added to digesters. All the digesters were run simultaneously under controlled temperature at 37 ± 0.1 °C. The length of experiment was 25 days. The results showed that all crop residues significantly increased biogas production and net CH4 volume at all C/N ratios, among which corn stalks performed the best with increase in daily maximum biogas volume by 11.4-fold as compared to the control, followed by oat straw (8.45-fold) and wheat straw (6.12-fold) at the C/N ratio of 20/1, which was found to be the optimal C/N ratio for co-digestion in the present study. In addition, corn stalks achieved the highest CH4 content in the biogas (~68%), which was about 11% higher than that of oat straw (~57%), whereas wheat straw and the control both had produced biogas with ~47% CH4 content. Wheat straw demonstrated a lower biogas productivity than corn stalks and oat straw even it had a higher carbon content (46%) than the latter two residues (39%).

Xiao Wu

Papers

Biogas and CH4 productivity by co-digesting swine manure with three crop residues as an external carbon source.

States and challenges for high-value biohythane production from waste biomass by dark fermentation technology

Biogas and CH4 Productivity by Co-Digesting Swine Manure with Three Crop Residues as an External Carbon Source

Continuous biohydrogen production from liquid swine manure supplemented with glucose using an anaerobic sequencing batch reactor

Effect of pH on continuous biohydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor