Key Laboratory of Algal Biology of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Environ Sci Pollut Res Int. 2021 Aug;28(31):42082-42092. doi: 10.1007/s11356-021-13664-5. Epub 2021 Apr 1.
A mechanical harvesting technology based on coupling flocculation with a rotary drum filter (RDF, 35-μm) was applied to remove cyanobacterial blooms and produce clean water in Lake Caohai, a sub-lake of Lake Dianchi (Kunming, China). After treatment with a shipboard RDF and cationic polyacrylamide (CPAM, 0.5-2 mg/L) flocculation, > 95% of cyanobacterial biomass was removed. The chlorophyll-a (Chl-a) concentration and turbidity in the effluent were < 8 μg/L and < 3 NTU, respectively. Nutrient concentrations were also markedly reduced, with a permanganate index (PI) of < 2 mg/L and total phosphorus concentration of < 20 μg/L. The total nitrogen concentration was reduced from 2.75 to 1.65 mg/L, and most of the residual nitrogen was nitrate. Although powerful for the removal of suspended particles and an enhanced water transparency, the combined technology showed no significant reduction in inorganic nutrients and only a slight reduction in dissolved organic matter (DOM). The concentrations of protein and polysaccharide were significantly reduced, while that of humic matter did not change during the process. After flushing with the effluent of the RDF, a 20,000-m enclosure of lake water became clear when the volume of the effluent was 1.8 times that of the water enclosure. The electrical energy per order (EE/O) was calculated to be 0.053kWh/m, which is lower than that of transferring water from more than 10 km away (0.058 kWh/m). Thus, a shipboard RDF coupled with CPAM flocculation is a promising approach to remove harmful cyanobacterial blooms and improve the water environment of eutrophic lakes.
基于耦合絮凝与转鼓式过滤器（RDF，35μm）的机械收获技术被应用于去除滇池子湖草海的蓝藻水华并生产清洁水。经过船上 RDF 和阳离子聚丙烯酰胺（CPAM，0.5-2mg/L）絮凝处理后，超过 95%的蓝藻生物质被去除。出水的叶绿素-a（Chl-a）浓度和浊度分别<8μg/L 和<3NTU。营养物浓度也明显降低，高锰酸盐指数（PI）<2mg/L，总磷浓度<20μg/L。总氮浓度从 2.75 降低到 1.65mg/L，且大部分残留氮为硝酸盐。尽管该联合技术对悬浮颗粒物的去除和水透明度的提高具有强大作用，但对无机营养物的去除没有显著影响，对溶解有机物（DOM）的去除作用也很微弱。蛋白质和多糖的浓度显著降低，而腐殖质的浓度在处理过程中没有变化。在用 RDF 出水冲洗后，当出水体积是水围体积的 1.8 倍时，20000m3的湖水变得清澈。每级的电能（EE/O）计算为 0.053kWh/m，低于从 10 多公里以外调水的电能（0.058kWh/m）。因此，船上 RDF 与 CPAM 絮凝相结合是去除有害蓝藻水华和改善富营养化湖泊水环境的一种很有前景的方法。
