Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Campus Pampulha, 31270-901 Belo Horizonte, MG, Brazil; Group of Environmental Engineering and Microbiology, Department Civil and Environmental Engineering, Universitat Politècnica de Catalunya, c/ Jordi Girona 1-3, Barcelona 08034, Spain.
Department of Agricultural Engineering, Federal University of Viçosa, Av. Peter Henry Rolfs, s/n, Campus Universitario, 36570-900 Viçosa, MG, Brazil.
Sci Total Environ. 2024 Jul 15;934:173301. doi: 10.1016/j.scitotenv.2024.173301. Epub 2024 May 15.
The increase in food waste generation has resulted in significant challenges for its sustainable management. Anaerobic digestion coupled with microalgae-based ponds for digestate treatment can be used as a low-cost eco-friendly technology approach. In this case, microalgal biomass harvested from the ponds may be valorized into bioenergy (biogas) and soil conditioner and/or biofertilizers. The aim of the present study was to evaluate the microalgal biomass produced from a food waste digestate treatment ponds as agricultural fertilizer. For this purpose, microalgal biomass was tested before and after anaerobic digestion and co-digestion with food waste, exploring its potential for valorization. The inorganic fertilizer urea and soil with no fertilization were also used as treatments. The experimental design consisted of applying the treatments in pots cultivated with hybrid grass Brachiaria cv. Sabiá and distributed in randomized blocks in a controlled greenhouse. Microalgal biomass was mainly composed by Scenedesmus sp.. The assessed parameters showed comparable results on plant growth (i.e. number of tillers, fresh and dry matter and Chlorophyll content index) for fresh and digested microalgal biomass and inorganic fertilizer. Furthermore, it was observed that fresh microalgae provided the highest Phosphorus content in the leaf (21 %). Additionally, there were increases of 9 % in Nitrogen and 12 % in organic matter in the soil after applying digested microalgae compared to the control group without any fertilization. Finally, experimental data obtained suggests that microalgae-based biofertilizer holds the potential to replace inorganic fertilizer as a nutrient source. Moreover, it contributes to the valorization of by-products from organic waste treatment.
食物浪费产生的增加对其可持续管理带来了重大挑战。厌氧消化与基于微藻的池塘相结合，用于处理消化物，可以作为一种低成本的环保技术方法。在这种情况下，从池塘中收获的微藻生物质可以被增值为生物能源（沼气）和土壤调节剂和/或生物肥料。本研究的目的是评估从食物废物消化物处理池塘中产生的微藻生物质作为农业肥料的潜力。为此，在厌氧消化和与食物废物共消化之前和之后测试了微藻生物质，探索了其增值的潜力。无机肥料尿素和没有施肥的土壤也被用作处理方法。实验设计包括在装有杂交草 Brachiaria cv. Sabiá 的盆中应用处理方法，并在可控温室中的随机块中分布。微藻生物质主要由 Scenedesmus sp. 组成。评估的参数显示，新鲜和消化的微藻生物质以及无机肥料在植物生长（即分蘖数、鲜重和干重以及叶绿素含量指数）方面的结果相当。此外，观察到新鲜微藻在叶片中提供了最高的磷含量（21%）。此外，与没有任何施肥的对照组相比，施用消化后的微藻后，土壤中的氮增加了 9%，有机物质增加了 12%。最后，实验数据表明，基于微藻的生物肥料有可能替代无机肥料作为营养源。此外，它有助于有机废物处理的副产品的增值。
