MEtRICs, Mechanical Engineering and Resource Sustainability Center, Department of Science and Technology of Biomass, FCT-NOVA, Campus de Caparica, 2829-516, Caparica, Portugal.
LNEG - Laboratório Nacional de Energia e Geologia, I.P./Bioenergy and Bioerefineries Unit, Estrada do Paço do Lumiar 22, 1649-038, Lisbon, Portugal; GreenCoLab - Green Ocean Technologies and Products Collaborative Laboratory, CCMAR, Algarve University, Portugal.
J Environ Manage. 2021 May 15;286:112187. doi: 10.1016/j.jenvman.2021.112187. Epub 2021 Feb 17.
The use of microalgae to remediate raw effluent from brown crab aquaculture was evaluated by performing batch mode growth tests using separately the microalgae Chlorella vulgaris (Cv), Scenedesmus obliquus (Sc), Isochrysis galbana (Ig), Nannocloropsis salina (Ns), and Spirulina major (Sp). Removal efficiencies in batch growth were 100% for total nitrogen and total phosphorus for all microalgae. Chemical oxygen demand (COD) remediations were all above 72%. Biomass productivity varied from 20.9 mg L day (N. salina) to 146.4 mg L day (C. vulgaris). The two best performing algae were C. vulgaris and S. obliquus and they were tested in semi-continuous growth, reaching productivities of 879.8 mg L day and 811.7 mg L day, respectively. The bioremediation of the effluent was tested with a transfer system consisting of three independent containers and compared with the use of a single container. The single container had the same capacity and received weekly the same volume of effluent as the three containers together. The remediation capacity of the 3 containers was much higher than the single one. The supplementation with NaNO was tested to improve the nutrient removal microalgae' capacity, with positive results. The removal efficiencies were 100% for total nitrogen and total phosphorus and higher than 96% for COD. The obtained C. vulgaris and S. obliquus biomass were composed of 31 and 35% proteins, 6 and 8% lipids, 39 and 30% carbohydrates, respectively. The composition of these biomass suggest that it can be used as novel and sustainable ingredients in aquaculture feeds. The algal biomass of Cv and Sc were used as biostimulants in the germination of wheat and watercress, and very promising results were attained, with increases in the germination index for Cv and Sc of 175% and 48% in watercress and 84% and 98% in wheat, respectively. The biomasses of Cv and Sc were also subjected to a torrefaction process with 72.5 ± 1.7% char yields. The obtained biochars were tested as biostimulants for germination seeds (wheat and watercress) and as bio-adsorbent of dye solutions.
采用分批培养模式，分别用小球藻（Cv）、斜生栅藻（Sc）、盐藻（Ig）、盐生杜氏藻（Ns）和钝顶螺旋藻（Sp）对褐蟹养殖原水进行修复效果评估。所有微藻对总氮和总磷的去除率均达到 100%。化学需氧量（COD）的去除率均在 72%以上。生物量生产力从 20.9mg/L·d（N. salina）到 146.4mg/L·d（C. vulgaris）不等。两种表现最好的藻类是 C. vulgaris 和 S. obliquus，它们在半连续培养中进行了测试，分别达到 879.8mg/L·d 和 811.7mg/L·d 的生产力。通过由三个独立容器组成的转移系统对废水的生物修复进行了测试，并与使用单个容器进行了比较。单个容器的容量相同，每周接收的废水量与三个容器相同。三个容器的修复能力远高于单个容器。测试了添加 NaNO 以提高微藻去除营养物的能力，结果为正。总氮和总磷的去除率均达到 100%，COD 的去除率高于 96%。获得的 C. vulgaris 和 S. obliquus 生物质分别由 31%和 35%的蛋白质、6%和 8%的脂质、39%和 30%的碳水化合物组成。这些生物质的组成表明，它可以作为水产养殖饲料的新型可持续成分。将 Cv 和 Sc 的藻生物质用作小麦和豆瓣菜种子萌发的生物刺激剂，取得了非常有前景的结果，豆瓣菜的 Cv 和 Sc 的萌发指数分别增加了 175%和 48%，小麦的萌发指数分别增加了 84%和 98%。将 Cv 和 Sc 的生物质进行了 72.5±1.7%产率的热解。所得生物炭用作种子萌发（小麦和豆瓣菜）的生物刺激剂和染料溶液的生物吸附剂进行了测试。
