Response surface design for the optimization of the removal of chlorella pyrenoidosa low frequency ultrasonic irradiation

Abstract

Water blooms caused by blue and greet cyanobacteria has been shown to be hazardous to both animals and humans. Ultrasonic algae removal technology can be good for controlling algae growth by appropriate power, frequency and irradiation time. First of all, the approximate ranges of the ultrasonic parameters, frequency, power and irradiation time, were estimated with single factor experiments. Then the optimized values of the three parameters were determined by central composite design of response surface design. Results showed that the removal rate of chlorophyll-a reached to 64.1 % after the irradiation for 7 min by ultrasonic of 77 kHz and 100 W. Ultrasonic technology can remove Chlorella pyrenoidosa in water quickly and effectively, so as to achieve the purpose of water purification.