| Title: | Biomass pre-treatments of the N(2)-fixing cyanobacterium Tolypothrix for co-production of methane |
| Author(s): | Velu C; Karthikeyan OP; Brinkman DL; Cires S; Heimann K; |
| Address: | "College of Science Engineering, James Cook University, Townsville, 4811, Queensland, Australia. Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, 48109, MI, USA. Electronic address: opkens@gmail.com. Australian Institute of Marine Science, Townsville, Australia. Department of Biology Autonoma de Madrid University, Madrid, ES-28049, Spain. Centre for Marine Bioproduct Development, Flinders University, Bedford Park, SA, 5042, Australia. Electronic address: kirsten.heimann@flinders.edu.au" |
| DOI: | 10.1016/j.chemosphere.2021.131246 |
| ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
| Abstract: | "Tolypothrix, a self-flocculating, fast growing, CO(2) and nitrogen-fixing cyanobacterium, can be cultivated in nutrient-poor ash dam waters of coal-fired power stations, converting CO(2) emissions into organic biomass. Therefore, the biomass of Tolypothrix sp. is a promising source for bio-fertiliser production, providing micro- and macronutrients. Energy requirements for production could potentially be offset via anaerobic digestion (AD) of the produced biomass, which may further improve the efficiency of the resulting biofertilizer. The aim of this study was to evaluate the effectiveness of pre-treatment conditions and subsequent methane (CH(4)) production of Tolypothrix under out-door cultivation conditions. Pre-treatments on biogas and methane production for Tolypothrix sp. biomass investigated were: (1) thermal at 95 degrees C for 10 h, (2) hydrothermal by autoclave at 121 degrees C at 1013.25 hPa for 20 min, using a standard moisture-heat procedure, (3) microwave at an output power of 900 W and an exposure time of 3 min, (4) sonication at an output power of 10 W for 3.5 h at 10 min intervals with 20 s breaks and (5) freeze-thaw cycles at -80 degrees C for 24 h followed by thawing at room temperature. Thermal, hydrothermal and sonication pre-treatments supported high solubilization of organic compounds up to 24.40 g L(-1). However, higher specific CH(4) production of 0.012 and 0.01 L CH(4) g(-1) volatile solids(added.) was achieved for thermal and sonic pre-treatments, respectively. High N- and low C-content of the Tolypothrix biomass affected CH(4) recovery, while pre-treatment accelerated production of volatile acids (15.90 g L(-1)) and ammonia-N-accumulation (1.41 g L(-1)), leading to poor CH(4) yields. Calculated theoretical CH(4) yields based on the elemental composition of the biomass were ~55% higher than actual yields. This highlights the complexity of interactions during AD which are not adequately represented by elemental composition" |
| Keywords: | Anaerobiosis Biofuels Biomass *Cyanobacteria *Methane Anaerobic co-digestion Ash dam water Horizontal algal turf scrubbers Methane Volatile organics; |
| Notes: | "MedlineVelu, Chinnathambi Karthikeyan, Obulisamy Parthiba Brinkman, Diane L Cires, Samuel Heimann, Kirsten eng England 2021/09/03 Chemosphere. 2021 Nov; 283:131246. doi: 10.1016/j.chemosphere.2021.131246. Epub 2021 Jun 19" |
