Experimental study on the disinfection efficiencies of a continuous-flow ultrasound/ultraviolet baffled reactor

Abstract

A self-designed continuous-flow ultrasound/ultraviolet (US/UV) baffled reactor was tested in this work, and the disinfection efficiency of secondary effluent from a wastewater treatment plant (WWTP) was investigated in terms of the different locations of ultrasonic transducers inside the reactor under similar input power densities and specific energy consumptions. Results demonstrated that the two-stage simultaneous US/UV irradiation in both chambers 2 and 3 at a flow rate of 1200 L/h performed excellent disinfection efficiency. It achieved an average feacal coliforms concentration of 201±78 colony forming unit (CFU)/L in the effluent and an average of (4.24±0.26) log10 reduction. Thereafter, 8 days of continuous operation was performed under such a condition. A total of 31 samples were taken, and all the samples were analyzed in triplicate for feacal coliforms analysis. Experimental results showed that feacal coliforms concentrations remained at about 347±174 CFU/L under the selected optimum disinfection condition, even if the influent concentrations fluctuated from 3.97×10(5) to 3.57×10(6) CFU/L. This finding implied that all effluents of continuous-flow-baffled-reactor with simultaneous US/UV disinfection could meet the requirements of the discharge standard of pollutants for municipal WWTP (GB 18918-2002) Class 1-A (1000 CFU/L) with a specific energy consumption of 0.219 kWh/m(3). Therefore, the US/UV disinfection process has great potential for practical applications.

Disinfection effect of a continuous-flow ultrasound/ultraviolet baffled reactor at a pilot scale

“…Similar results were achieved when the reactor was previously operated at a WWTP with a biological oxidation ditch process. The average disinfection effluent and log reduction of fecal coliforms were 347 CFU/L and 3.78 log, respectively [16].…”

“…Experiments to find the optimal operation condition that could satisfy the national discharge standard of pollutants for municipal WWTP (GB 18918-2002) were conducted previously at a pilot scale. The suggested operation condition was US simultaneous disinfection with one UV lamp in both chamber 2 and chamber 3, respectively [16]. However, the comprehensive systematic evaluation of the disinfection process need to be investigated further before industrial application.…”

Adaptation of domestic effluent for agricultural reuse by biological, physical treatment and disinfection by ultraviolet radiation

“…In this sense, a disinfection as tertiary treatment becomes essential, considering the high burden of pathogens usually present in domestic effluents, in order to ensure the integrity of human health (Zhou et al, 2015).…”

Sonophotocatalytic degradation of trypan blue and vesuvine dyes in the presence of blue light active photocatalyst of Ag3PO4/Bi2S3-HKUST-1-MOF: Central composite optimization and synergistic effect study

“…In odder word, hybrid systems including of two or more individual AOPs have higher efficiency for degradation pollutants [17]. Combination of sonolysis and photocatalysis as sonophotodegradation methods is an efficient technique for degradation of organic compounds [18][19][20][21]. In sonophotocatalyst degradation process ultrasonic waves and light irradiation are applied simultaneously to a system containing a photocatalyst [22].…”