Alireza Zahraei Ramazani; Majid Kababian; Hasan Vatandoost; Mozhgan Baniardalani; Seyed Hassan Musa Kazemi; Saideh Yousefi; Amir Hossein Mahvi; Amrullah Azarm; Soudebeh Hamedi Shahraki; Shahrokh Izadi; Zahra Hajivand; Hamed Zahraei Ramazani
Abstract
Background and purpose: Mosquito-borne diseases are serious health problems in many countries around the world, and the widespread distribution of their vectors has a major impact on the transmission and spread of these diseases. Mosquitoes play a key role in transmitting arboviruses such as West Nile, ...
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Background and purpose: Mosquito-borne diseases are serious health problems in many countries around the world, and the widespread distribution of their vectors has a major impact on the transmission and spread of these diseases. Mosquitoes play a key role in transmitting arboviruses such as West Nile, Dengue Fever, Chikungunya, Sindbis, Zika, Rift Valley Fever, Batai virus, Usutu virus, East Horse Encephalitis (EEE), and West Nile Virus (WNV), and also some suspected emerging viral agents, such as SARS-CoV-2 (causative agent of COVID-190) and the Zika Virus in the world.There are several methods for mosquitoes larval control. An important challenge in mosquitoes control programs is their resistance to different groups of insecticides. The ultrasonic device is a novel and natural friendly approach for controlling insecticide resistance mosquitoes.Materials and methods: In this study, Ultrasonic TI-H5 device of Elma Company were used against 4th instar larvae of Culex pipiens under laboratory condition. Different variables including; Electrical power (50,100,200, 250 watts), exposure times (1, 2.5, 5, 10, 15 minutes) at two frequencies of 35, and 130 Kilohertz were employed.Results: Mortality of 4th instar larvae at 35 KH and different exposure time with specific Electronic power was 100%. In 130 KH with increasing exposure time, the mortality was increased.Conclusion: Insecticides are one of the causes of environmental and water pollution. Also, due to the resistance of mosquitoes to insecticides, the new safe, cost-effective and effective method in integrated pest management programs is the control of mosquito larvae using ultrasonic waves.
Farshad Golbabei Kootenaei; Nasser Mehrdadi; Gholamreza Nabi Bidhendi; Hasan Aminirad; Mahdi Asadi Ghalhari; Farima Saeedi
Abstract
Abstract Background and purpose: Reducing the amount of sludge produced by the biological treatment of active sludge is of great importance. The main task of dewatering unit is to separate water from excess sludge. The aim of this study is to determine the effect of ultrasonic waves on coagulants in ...
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Abstract Background and purpose: Reducing the amount of sludge produced by the biological treatment of active sludge is of great importance. The main task of dewatering unit is to separate water from excess sludge. The aim of this study is to determine the effect of ultrasonic waves on coagulants in improving the sludge dewatering process and increasing solid content of sludge cake. Materials and methods:This is an experimental study performed in batch laboratory scale. During the two seasons, 12 samples were taken at 15 days’ intervals. Variables include ultrasound density (0.375, 0.75, 1, 1.3 and 2.5) in watts per ml, Time (1, 5, 10, 15 and 30) in minute, and specific energy input (208, 1041, 2083, 3124 and 6249) in kilojoule on kilo total suspended solids. The effects of ultrasonic waves on coagulants were investigated by using Particle Size Analizer (PSA). Results:The optimum amount of solid content of sludge and capillary suction time (CST) was equal to 26.4 percent and 86 seconds in sonification time of 5 minutes and specific energy input of 1041 kj/kg TS. By applying ultrasonic waves, d10, d50, d90 and average particle size amount were equal to 6.3, 44.2, 24.4 and 28.84 micrometers respectively. Conclusion:Ultrasound waves create pores in the physical structure of the polymers and the increase of cationic surface charge increases the adsorption of particles and made larger flocs and can increase the solid content of sludge and improve sludge dewatering process.