Liu Bo-Dong, Dong Hao-Tao, Rong Hong-Wei, Zhang Rui-Jian
Research Center, Guangzhou Municipal Engineering Design & Research Institute, Guangzhou, 510060, China.
International Department, The Affiliated High School of South China Normal University, Guangzhou, 510630, China.
Environ Sci Pollut Res Int. 2022 Dec;29(56):85482-85491. doi: 10.1007/s11356-022-21856-w. Epub 2022 Jul 7.
Chironomids are abundant insects in freshwater ecosystems and lay in still or slow-moving water. The walls of sedimentation tanks in drinking water treatment plants (DWTP) provide such laying habitat, which can lead to larval outbreaks in plant effluent. While chironomid larvae are often associated with poor hygiene, effective methods to control outbreaks are needed. Here, we assessed the effect of ultrasound treatment on Chironomus kiiensis' eggs. The mortality rate of eggs was examined after ultrasound treatment, and the protein content (heat shock protein 70 and hemoglobin) and enzymatic activities of acetylcholinesterase, cytochrome P, and glutathione S-transferases involved in the ultrasound-induced stress response were analyzed before and after treatment. COMSOL software was also used to examine the characteristics of the ultrasonic field, including frequency, power, exposure distance, and time. Higher egg mortality was observed at lower frequencies. At 28 kHz, 450 W, 15-mm exposure distance, and 75-s exposure time, 72.4% of eggs showed apoptosis after exposure. At higher frequencies (68 kHz), mortality decreased to 50.9%. Exposure time and distance also significantly affected egg mortality. From the geometric models, it could be seen that C. kiiensis' eggs sustained much greater acoustic pressure (2379 Pa) with 28-kHz exposure than that with 68-kHz exposure (422 Pa); however, the propagation distance was greater at the higher frequency. The hydraulic shear force effect of the ultrasonic radiation appeared to be the primary factor in egg mortality. We expected that array of ultrasonic transducers embedded in the walls of water treatment plants could be effective in killing Chironomus' eggs and highlight the potential for ultrasound as an effective treatment for the prevention of Chironomus outbreaks in treatment plant effluents.
摇蚊是淡水生态系统中数量众多的昆虫，它们在静止或流动缓慢的水中产卵。饮用水处理厂（DWTP）沉淀池的池壁提供了这样的产卵栖息地，这可能导致工厂排放水中幼虫大量爆发。虽然摇蚊幼虫通常与卫生条件差有关，但仍需要有效的方法来控制其爆发。在此，我们评估了超声处理对基氏摇蚊卵的影响。超声处理后检测卵的死亡率，并分析处理前后参与超声诱导应激反应的乙酰胆碱酯酶、细胞色素P和谷胱甘肽S -转移酶的蛋白质含量（热休克蛋白7 和血红蛋白）及酶活性。还使用COMSOL软件研究超声场的特性，包括频率、功率、暴露距离和时间。在较低频率下观察到较高的卵死亡率。在28kHz、450W、15mm暴露距离和75s暴露时间下，72.4%的卵在暴露后出现凋亡。在较高频率（68kHz）下，死亡率降至50.9%。暴露时间和距离也显著影响卵的死亡率。从几何模型可以看出，与68kHz暴露（422Pa）相比，28kHz暴露时基氏摇蚊的卵承受的声压（2379Pa）要大得多；然而，较高频率下的传播距离更大。超声辐射的水力剪切力效应似乎是导致卵死亡的主要因素。我们期望嵌入水处理厂池壁的超声换能器阵列能有效杀死摇蚊卵，并突出超声作为预防处理厂排放水中摇蚊爆发的有效处理方法的潜力。
