The clogging of drippers due to the development of biofilms reduces the benefits and is an obstacle to the implementation of drip irrigation technology. The geometry of the dripper channel has an impact on the flow behaviours and head loss. The objective of this study was to analyse the influence of hydrodynamic parameters of three types of drippers (flow rates of 1, 2 and 4 l.h-1) fed by reclaimed wastewater on biofilm development kinetics and on the bacterial community. Using optical coherence tomography, we demonstrated that the inlet of the drippers (mainly the first baffle) and vortex zones are the most sensitive area for biofouling. Drippers with the lowest flow rate (1 l.h-1) and the smallest channel section were the favourable areas to biofouling. The low inlet velocity (0.34 m.s-1) in this type of dripper compared to 2 l.h-1 (0.61 25 m.s-1) and 4 l.h-1 (0.78 m.s-1) drippers can favour the deposition and development of biofilms. In addition, the water velocity influenced the structure of the bacterial communities in the biofilm. Low velocity (0.34 m.s-1) favoured the presence of Hydrogenophaga and Pseudoxanthomonas genera at the early stage of biofilm formation and filamentous bacteria belonging to Chloroflexi phylum at the end. So, maintaining a high flow rate and using drippers with a large flow cross-section is an effective way to control the development of biofilms by limiting the presence of filamentous bacteria.

中文翻译：

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流速的增加减少了由再生废水喂养的滴头中的丝状细菌引起的生物结垢和定殖

由于生物膜的发展而导致的滴头堵塞降低了其效益，并成为实施滴灌技术的障碍。滴头通道的几何形状会影响流动性能和压头损失。这项研究的目的是分析再生废水给水的三种类型的滴头（流速分别为1、2和4 lh-1）的流体力学参数对生物膜发育动力学和细菌群落的影响。使用光学相干断层扫描，我们证明了滴头（主要是第一个挡板）的入口和涡流区是生物污垢最敏感的区域。具有最低流速（1 lh-1）和最小通道截面的滴头是生物污垢的有利区域。与2 lh-1（0.61 25 m。）相比，这种滴头的入口速度低（0.34 ms-1）。s-1）和4 lh-1（0.78 ms-1）滴头可以促进生物膜的沉积和显影。另外，水流速影响生物膜中细菌群落的结构。低速（0.34 ms-1）有利于在生物膜形成的早期存在Hydrogenophaga和Pseudoxanthomonas属，而在末期则有利于属于绿叶弯曲杆菌的丝状细菌。因此，保持高流速并使用具有大流动横截面的滴头是通过限制丝状细菌的存在来控制生物膜发育的有效方法。s-1）赞成在生物膜形成的早期存在Hydrogenophaga和Pseudoxanthomonas属，而在末期则有利于属于叶绿藻的丝状细菌。因此，保持高流速并使用具有大流动横截面的滴头是通过限制丝状细菌的存在来控制生物膜发育的有效方法。s-1）赞成在生物膜形成的早期存在Hydrogenophaga和Pseudoxanthomonas属，而在末尾则支持属于叶绿单胞菌的丝状细菌。因此，保持高流速并使用具有大流动横截面的滴头是通过限制丝状细菌的存在来控制生物膜发育的有效方法。