The inhibition of cyanobacteria growth by allelochemicals, which controls harmful algal blooms has been examined in many studies. The objective of this work was to compare the efficiencies of different allelochemicals and determine a mixing proportion corresponding to the highest algae inhibiting activity and smallest adverse effect. The obtained results demonstrated that artemisinin, nonanoic acid, malonic acid, and ethyl acetate inhibited algal growth more efficiently than D-menthol and lactic acid. Synergies were observed in five groups of allelochemical combinations with inhibition ratios exceeding 80%, and the concentrations of extracellular microcystin-LR in the groups with high algal inhibition ratios were lower than that in the control group on the 7th day. No changes in extracellular polymeric substances compositions were detected after treatment. The permanganate indices of the treated groups were higher than that of the control group; however, this disparity gradually decreased with time. In addition, a sharp decrease in the concentration of dissolved inorganic phosphorus was observed for all treated groups. From the obtained data, the optimal proportion of mixed allelochemicals corresponding to 3.94 mg L−1 of artemisinin, 6.27 mg L−1 of nonanoic acid, 8.2 mg L−1 of malonic acid, and 6.38 mg L−1 of ethyl acetate was suggested.

中文翻译：

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混合化感物质对铜绿微囊藻生长、微囊藻毒素产生、胞外聚合物和水质的影响

许多研究已经研究了控制有害藻华的化感化学物质对蓝藻生长的抑制作用。这项工作的目的是比较不同化感物质的效率，并确定与最高藻类抑制活性和最小不利影响相对应的混合比例。所得结果表明青蒿素、壬酸、丙二酸和乙酸乙酯比D-薄荷醇和乳酸更有效地抑制藻类生长。抑制率超过80%的5组化感化学组合均观察到协同作用，第7天，高抑制率组胞外微囊藻毒素-LR浓度低于对照组。治疗后未检测到细胞外聚合物成分的变化。治疗组高锰酸盐指数高于对照组；然而，随着时间的推移，这种差距逐渐缩小。此外，观察到所有处理组的溶解无机磷浓度急剧下降。从获得的数据中，建议了对应于青蒿素 3.94 mg L-1、壬酸 6.27 mg L-1、丙二酸 8.2 mg L-1 和乙酸乙酯 6.38 mg L-1 的混合化感物质的最佳比例.