PhD Degree Program in Environmental Science, Environmental Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand.
Sci Total Environ. 2020 Apr 20;714:136577. doi: 10.1016/j.scitotenv.2020.136577. Epub 2020 Jan 8.
Microalgal biomass is often used as a raw material in methane production. Some microalgae possess a complex cell-wall structure which has a low degradability of microorganisms in anaerobic digestion. However, some microalgae produce glycolate, which is excreted outside the cell and can be used to produce methane under anaerobic condition. This research aims to investigate microalgal cultivation using wastewater to reduce nutrients and efficiently create glycolate. Two strains of microalgae (Acutodesmus sp. AARL G023, Chlorella sp. AARL G049) and two microalgal consortia were cultivated at dilutions of 0.5-fold (W50), 0.75-fold (W75) and undiluted wastewater (W100). The results showed that the microalgal consortium with undiluted wastewater (WCW100) consisted of Leptolyngbya sp. (30.4%), Chlorella sp. (16.1%) and Chlamydomonas sp. (52.2%), revealed the highest biomass productivity at 64.38 ± 14.54 mg·L·d and the highest glycolate productivity at 5.12 ± 0.48 mmol·L·d. The cultivation of microalgae effectively reduced ammonium‑nitrogen (NH-N) and soluble reactive phosphorus (SRP) levels in the wastewater at 43.5 ± 1.3% and 49.6 ± 6.9%. Furthermore, WCW100 showed the highest biogas productivity at 1.44 ± 0.07 mL·g·d and the highest methane content at 58.3 ± 6.0% v/v. This study indicates that there is a definite potential of using undiluted wastewater for microalgal biomass production and glycolate production that can reduce the wastewater volume and be applied as a raw material for methane production.
微藻生物质通常被用作甲烷生产的原料。一些微藻具有复杂的细胞壁结构，其在厌氧消化中微生物的降解性较低。然而，一些微藻产生的丙二酸是可以分泌到细胞外的，并且可以在厌氧条件下用于生产甲烷。本研究旨在利用废水培养微藻，以减少营养物质并有效地产生丙二酸。培养了两种微藻（Acutodesmus sp. AARL G023、Chlorella sp. AARL G049）和两种微藻共生体，稀释度分别为 0.5 倍（W50）、0.75 倍（W75）和未稀释废水（W100）。结果表明，未稀释废水（WCW100）中的微藻共生体由 Leptolyngbya sp.（30.4%）、Chlorella sp.（16.1%）和 Chlamydomonas sp.（52.2%）组成，生物量生产率最高，为 64.38±14.54 mg·L·d，丙二酸生产率最高，为 5.12±0.48 mmol·L·d。微藻的培养有效地将废水中的铵氮（NH-N）和可溶解性活性磷（SRP）水平降低了 43.5±1.3%和 49.6±6.9%。此外，WCW100 的沼气生产率最高，为 1.44±0.07 mL·g·d，甲烷含量最高，为 58.3±6.0% v/v。本研究表明，利用未稀释废水进行微藻生物质生产和丙二酸生产具有一定的潜力，可以减少废水体积，并可作为生产甲烷的原料。
