Assessment of Flat Emitter Anti-Clogging Performance in Drip Irrigation Systems

Abstract. Selecting drip emitters with excellent anti-clogging performance (AP) is vital to ensure the safe operation of drip irrigation systems. However, previous researchers have not reached a consensus on emitter selection and evaluation standards based on emitter AP. In this study, eight types of flat emitters were selected as experimental objects, and high-sand surface water was used as the water source to test the AP of emitters with three experimental treatments. The emitter total coefficient of evaluation index (ETEI) was applied to analyze the relative differences in AP of the emitters, and then the mechanism leading to those differences was explored. The results indicated that there were significant variations in AP among different emitters, and four evaluation indices had good consistency in evaluating emitter AP. Small-discharge emitters showed good anti-clogging ability. Emitters with large cross-section average velocity (v), not just with high discharge (Q), should be identified as having excellent AP. The combination of emitter structural parameters, mainly width-depth ratio (W/D), relative radius (A1/2/L), and flow path length (L), made significant differences in the v of emitters under the same operating conditions. Higher v caused a significant linear decrease in key clogging components, solid particles (SD), CaCO3 and MgCO3 precipitates (C-MP), extracellular polymeric substances (EPS), and microbial activity (MA), of the clogging material inside the emitter. This study provides a reference for the selection and development of emitter products with high-efficiency AP. Keywords: Anti-clogging ability, Emitter discharge, Evaluation indices, Micro-irrigation, Uniformity.