Civil and Environmental Engineering, University of Science and Technology (UST), Daejeon 34113, Korea.
Department of Environmental Research, Korea Institute of Civil Engineering and Building Technology (KICT), Goyang 10223, Korea.
Int J Environ Res Public Health. 2022 Oct 20;19(20):13577. doi: 10.3390/ijerph192013577.
The abundant growth in cyanobacterial blooms poses severe ecological threats with a high risk to aquatic organisms and global public health. Control of cyanobacterial blooms involves spraying cyanobacteria removal materials, including coagulants. However, little is known about the fate of the coagulated-cyanobacteria-laden water. Here, we examined long-term changes in water quality following treatment with various coagulants and minerals for cyanobacterial removal when the coagulated cyanobacterial cells were not removed from the water. An experiment in a controlled water system tested the effects of six different compounds, one conventional coagulant, two natural inorganic coagulants, and three minerals. All tested coagulants and minerals exhibited >75% of cyanobacterial removal efficiency. However, compared to the control, higher concentrations of nitrogen were observed from some samples treated during the experimental period. After 20 months, the final total phosphorus concentration of the raw water increased 20-fold compared to the initial concentration to 11.82 mg/L, indicating significant nutrient release over time. Moreover, we observed that the decomposition of sedimented cyanobacterial cells caused the release of intracellular contents into the supernatant, increasing phosphorous concentration over time. Therefore, cyanobacterial cells should be removed from water after treatment to prevent eutrophication and maintain water quality.
蓝藻水华的大量繁殖对水生生物和全球公共健康构成了严重的生态威胁。控制蓝藻水华的方法包括喷洒蓝藻去除材料，包括混凝剂。然而，对于凝结的含蓝藻水的去向知之甚少。在这里，我们研究了在不将凝结的蓝藻细胞从水中去除的情况下，用各种混凝剂和矿物去除蓝藻时，处理后水质的长期变化。在一个受控的水系统中进行的实验测试了六种不同化合物的效果，一种常规混凝剂、两种天然无机混凝剂和三种矿物质。所有测试的混凝剂和矿物质对蓝藻的去除效率都超过 75%。然而，与对照组相比，一些在实验期间处理的样品中观察到的氮浓度更高。20 个月后，与初始浓度相比，原水的最终总磷浓度增加了 20 倍，达到 11.82 毫克/升，表明随着时间的推移，营养物质释放显著增加。此外，我们观察到沉淀的蓝藻细胞分解会导致细胞内物质释放到上清液中，从而使磷浓度随着时间的推移而增加。因此，处理后应将蓝藻细胞从水中去除，以防止富营养化并保持水质。
