Zhao Yang, Xin Hongwei, Zhao Deiling, Zheng Weichao, Tian Wei, Ma He, Liu Kai, Hu Hui, Wang Tong, Soupir Michelle
Department of Agricultural and Biosystems Engineering, Iowa State University, USA.
Department of Agricultural and Biosystems Engineering, Iowa State University, USA, Department of Mechanical Engineering, Nanjing Institute of Industry Technology, China.
Ann Agric Environ Med. 2014;21(2):249-55. doi: 10.5604/1232-1966.1108585.
Spray-application of membraneless acidic electrolyzed water (MLAEW) is a novel technique for disinfection in livestock houses. This study investigated the loss of free chlorine (FC - the major germicidal component in MLAEW) over distance during spraying, as affected by air temperature and initial FC concentration. The anti-microbial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined.
MLAEW was prepared at two FC concentrations: app. 15 and 60 mg L⁻¹, and sprayed at three air temperatures (18, 25, 32 °C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5, 2 and 5-min treatments.
MLAEW aerosols collected at 0 cm lost 11.7-13.2% FC, compared with the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = 0.57). The rate of FC loss during travelling was 0.79-0.87 % per cm of aerosol travel distance (% cm⁻¹) at 18 °C, 1.08-1.15 % cm⁻¹ at 25 °C, and 1.35-1.49% cm⁻¹ at 32 °C. This travelling loss was affected by air temperature (P = 0.02), but not by initial FC concentration (P = 0.38). Bacteria were completely inactivated at 0.5 min when treated with MLAEW samples with FC > 16.8 mg L⁻¹, in 2 min when FC > 13.8 mg L⁻¹, and in 5 min when FC > 7.2 mg L⁻¹.
Airborne bacteria from aviary hen house can be effectively inactivated by MLAEW with adequate FC concentration and contact time. During spraying, the anti-microbial efficacy of MLAEW aerosols decreased over distance due to FC loss which exacerbated at higher air temperatures.
无膜酸性电解水（MLAEW）喷雾应用是一种用于禽舍消毒的新技术。本研究调查了喷雾过程中游离氯（FC，MLAEW中的主要杀菌成分）随距离的损失情况，以及空气温度和初始FC浓度对其的影响。研究了MLAEW对蛋鸡舍空气中细菌的抗菌效果。
制备了两种FC浓度的MLAEW：约15和60 mg L⁻¹，并在三种空气温度（18、25、32°C）下进行喷雾。分析了距喷嘴0、25和50 cm处收集的原始MLAEW溶液和MLAEW气溶胶的FC浓度。将细菌浸入这些MLAEW样品中，处理0.5、2和5分钟后进行活菌计数。
与原始MLAEW溶液相比，在0 cm处收集的MLAEW气溶胶损失了11.7 - 13.2%的FC。这种初始损失不受初始FC浓度（P = 0.13）和空气温度（P = 0.57）的影响。在18°C时，FC在气溶胶传播过程中的损失率为每厘米传播距离0.79 - 0.87%（% cm⁻¹），在25°C时为1.08 - 1.15% cm⁻¹，在32°C时为1.35 - 1.49% cm⁻¹。这种传播损失受空气温度影响（P = 0.02），但不受初始FC浓度影响（P = 0.38）。当用FC > 16.8 mg L⁻¹的MLAEW样品处理时，细菌在0.5分钟内完全失活，当FC > 13.8 mg L⁻¹时在2分钟内完全失活，当FC > 7.2 mg L⁻¹时在5分钟内完全失活。
具有足够FC浓度和接触时间的MLAEW可有效灭活蛋鸡舍空气中的细菌。在喷雾过程中，由于FC损失，MLAEW气溶胶的抗菌效果随距离降低，且在较高空气温度下加剧。
