Influence of operating pressure on emitter anti-clogging performance of drip irrigation system with high-sediment water

Abstract

Reducing emitters operating pressure has been widely acknowledged as one of the most effective approach to reduce drip irrigation system maintenance and operation costs. However, utilization of low-quality water, such as high-sediment water, reclaimed water, and brackish water, inevitably increases the emitters clogging risks. To examine the influence of different pressure levels on emitter clogging behavior and regulation path, an in-situ accelerated experiment of emitter clogging with high-sediment water was conducted with five operating pressure levels. The experiment was conducted from July 15, 2016, to October 15, 2016 with a total running time of 720 h. The results showed that emitter anti-clogging capability was gradually decreased as the operating pressure decreased below 100 to 60 kPa and was significant decreased as the operating pressure decreased below 60 to 40 kPa or lower. Therefore, the operating pressure should be kept above 60 kPa to maintain the favorable emitter anti-clogging performance. The change of the operating pressure directly and indirectly influenced the formation of clogging substance in the emitters. In addition, at different operating pressures, the anti-clogging performance parameters discharge ratio variation (Dra), coefficient of uniformity (CU), statistical uniformity coefficient (Us), emitter discharge variation (qvar), clogging substance within emitters (CSE) and clogging substance within laterals (CSL) were linearly correlated with anti-clogging performance parameters (Dra, CU, Us, qvar, CSE, CSL) of 100 kPa. Therefore, basing the Dra, CU, Us, qvar, CSE and CSL at 100 kPa, a simple linear model was established to predict anti-clogging performance parameters at the different pressures e.g. 20, 40, 60 and 80 kPa. This study could provide technical support for the application and promotion of the drip irrigation system with high-sediment water.