再生水滴灌条件下滴头堵塞特性评估

Evaluation of drip emitter clogging with reclaimed wastewater irrigation

针对再生水水质复杂,污染物众多,其在农业滴灌上的应用对滴灌系统的抗堵塞能力要求更高的特点,采用6种滴头进行约360h的再生水滴灌试验,测定了再生水滴灌条件下滴头堵塞规律,探讨了滴头流道尺寸参数对于堵塞规律的影响,并采用环境扫描电子显微镜技术分析了滴头堵塞物质的组成结构。试验结果表明:不同流道结构的滴头抗堵塞能力明显不同,各类滴头流量下降的幅度范围为14.4%～72.2%;流道水力直径、流道长度、锯齿高度和锯齿间距等参数都影响着堵塞的发生,其中以水力直径代表性最好,分区域地呈负相关关系;微生物、胞外多聚物以及颗粒物质混合形成的絮状结构,构成了滴头流道内的主要沉积物;堵塞过程的发生往往是以微生物富集开始的。试验结果有助于进一步提高再生水滴灌的应用水平。

With the growing utilization of drip irrigation with wastewater,emitter anti-clogging capability becomes a critical problem.Six representative type drip emitters were tested with 360 h reclaimed wastewater irrigation.The influence of emitter path dimensions in the clogging process was tested using statistics methods,and the sediments in the flow path were analyzed by environmental scanning electron microscope（ESEM） after the whole irrigation.The results indicated that the different type of emitter showed the different discharge decline process and the range of discharges reduction in this experiment is 14.4%-72.2%.Hydraulic diameter,length,dentation space,dentation height of flow path had the influences on the clogging process and the hydraulic diameter showed the inverse relationship on the plugging process in the respective regions.The particles in the matrix of the bacteria（biofilm） coupling extracellular polysaccharides and forming flocculation were found in the emitter flow path and the clogging process started from microorganism sediment in this experiment.The results were helpful to the emitter anti-clogging design for the reclaimed wastewater application on drip irrigation.