Shayesteh Hajar, Vadiveloo Ashiwin, Bahri Parisa A, Moheimani Navid R
Algae R&D Centre, Discipline of Environmental and Conservation Sciences, Murdoch University, WA, 6150, Australia.
Algae R&D Centre, Discipline of Environmental and Conservation Sciences, Murdoch University, WA, 6150, Australia; Centre for Water, Energy and Waste, Harry Butler Institute, Murdoch University, Murdoch, WA, 6150, Australia.
J Environ Manage. 2022 Dec 1;323:116322. doi: 10.1016/j.jenvman.2022.116322. Epub 2022 Sep 22.
Sufficient and reliable long-term field data on the growth, productivity and nutrient removal rates of microalgal based wastewater treatment system is essential to validate its overall techno-economic feasibility. Here, we investigated the semi-continuous microalgal cultivation of Scenedesmus sp. in anaerobically digested abattoir effluent (ADAE) for 13 months in outdoor raceway ponds operated at 20 cm depth. This study was initiated with three different cultures consisting of 1) monocultures of Chlorella sp., 2) Scenedesmus sp., and 3) an equal mixed concentration of both microalgae species. However, after 15 weeks, Scenedesmus sp. was found to be the most dominant microalgae species in all the different cultures, even completely taking over the Chlorella sp. monoculture. Over the course of summer and early autumn, the average weekly biomass productivity of Scenedesmus sp. cultures was 12.5 ± 0.6 g m d which was 16% and 30% higher than productivities recorded in spring and winter, respectively. All available ammoniacal nitrogen (NH-N) was found to be exhausted during each growth period with an average 33.6% nitrogen assimilation rate. The average rate of phosphate and COD (chemical oxygen demand) removals were 85.2% and 37.5% throughout the cultivation period. No significant differences were found in carbohydrate, lipid and protein content of Scenedesmus sp. during different seasons of the year. Over 53% increase in biomass productivity can be achieved if CO is added to control culture pH at pH 6.5. Here, we successfully demonstrated reliability of continuous long-term cultivation of microalgae in ADAE for simultaneous wastewater treatment and algal biomass production.
关于基于微藻的废水处理系统的生长、生产力和养分去除率的充分且可靠的长期实地数据对于验证其整体技术经济可行性至关重要。在此，我们在深度为20厘米的室外跑道池中对绿藻在厌氧消化的屠宰场废水（ADAE）中进行了13个月的半连续微藻培养研究。本研究起始于三种不同的培养物，分别为：1）小球藻单培养物；2）绿藻；3）两种微藻的等混合浓度培养物。然而，15周后，发现绿藻是所有不同培养物中最占优势的微藻物种，甚至完全取代了小球藻单培养物。在夏季和初秋期间，绿藻培养物的平均每周生物量生产力为12.5±0.6克/平方米·天，分别比春季和冬季记录的生产力高16%和30%。在每个生长周期中，所有可用的氨氮（NH-N）都被耗尽，平均氮同化率为33.6%。在整个培养期间，磷酸盐和COD（化学需氧量）的平均去除率分别为85.2%和37.5%。在一年的不同季节中，绿藻的碳水化合物、脂质和蛋白质含量未发现显著差异。如果添加二氧化碳将对照培养物的pH值控制在6.5，生物量生产力可提高超过53%。在此，我们成功证明了在ADAE中连续长期培养微藻以同时进行废水处理和藻类生物质生产的可靠性。
