Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan.
Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan.
Chemosphere. 2022 Mar;291(Pt 1):133057. doi: 10.1016/j.chemosphere.2021.133057. Epub 2021 Nov 25.
Utilizing wastewaters as feedstock for microalgal cultivation has the dual benefits of water-saving and low nutrient costs, with simultaneous remediation of pollutants and generation of value-added biochemical products. This study employed two different strategies to treat raw dairy wastewaters with moderate and high chemical oxygen demand (COD) levels. For moderate-COD dairy wastewater, the wastewater was directly utilized as feedstock for algal cultivation, in which the effects of wastewater dilution ratios and algal inoculum sizes were investigated. The results show that the microalga strain used (Chlorella sorokiniana SU-1) was capable of obtaining a high biomass concentration of 3.2 ± 0.1 g/L, accompanied by 86.8 ± 6%, 94.6 ± 3%, and 80.7 ± 1%, removal of COD, total phosphorus (TP) and total nitrogen (TN), respectively. Meanwhile, the obtained microalgal biomass has lipids content of up to 12.0 ± 0.7% at a wastewater dilution ratio of 50% and an inoculum size of 2 g/L. For high-COD dairy wastewater, an integrated process of anaerobic digestion and microalgal phycoremediation was employed, and the effect of inoculum sizes was also studied. The inoculum size of 2 g/L gave highest biomass production of 4.25 ± 0.10 g/L with over 93.0 ± 2.0% removal of COD, TP, and TN. The harvested microalgal biomass has lipids and protein content of 12.5 ± 2.2% and 18.0 ± 2.2%, respectively. The present study demonstrated potential microalgal phycoremediation strategies for the efficient COD removal and nutrients recovery from dairy wastewater of different COD levels with simultaneous production of microalgal biomass which contains valuable components, such as protein and lipids.
利用废水作为微藻培养的原料具有节水和低营养成本的双重好处，同时还可以修复污染物并产生增值的生化产品。本研究采用两种不同的策略来处理中高化学需氧量（COD）水平的原奶废水。对于中 COD 牛奶废水，直接将废水用作藻类培养的原料，研究了废水稀释比和藻类接种量的影响。结果表明，所使用的微藻菌株（Chlorella sorokiniana SU-1）能够获得 3.2±0.1g/L 的高生物量浓度，同时 COD、总磷（TP）和总氮（TN）的去除率分别为 86.8±6%、94.6±3%和 80.7±1%。同时，在废水稀释比为 50%和接种量为 2g/L 的条件下，所得微藻生物质的脂质含量高达 12.0±0.7%。对于高 COD 牛奶废水，采用厌氧消化和微藻光修复集成工艺，并研究了接种量的影响。接种量为 2g/L 时，生物量产量最高，为 4.25±0.10g/L，COD、TP 和 TN 的去除率均超过 93.0±2.0%。收获的微藻生物质的脂质和蛋白质含量分别为 12.5±2.2%和 18.0±2.2%。本研究为不同 COD 水平的牛奶废水的高效 COD 去除和养分回收提供了潜在的微藻光修复策略，同时还生产了含有蛋白质和脂质等有价值成分的微藻生物质。
