Effect of different water quality on the performance of pressure compensating emitter in drip irrigation systems

Pressure-compensating emitters (PCE) ensure consistent flow rates and uniform irrigation in drip irrigation systems across varying pressures. However, the performance of PCE can be significantly compromised by marginal water, characterized by impurities like particulate matter, salt ions, microorganisms and organic substances. To date, research elucidating the factors contributing to PCE performance reduction with marginal water sources has been limited. This study investigated the effects of tour types of marginal waters on PCE performances, specifically saline water (rich in salt ions), high-sediment water, biogas slurry (rich in organics) and reclaimed water (containing microorganisms), under three operational pressures (0.1 MPa, 0.2 MPa, 0.3 MPa). Variations in clogging substances and diaphragm performance within the PCE flow channel were analysed. Results indicated that PCE performance declined most rapidly in saline water, followed by high-sediment water, biogas slurry and reclaimed water. Compared to clogging substances within the flow channel in reclaimed water conditions, those in biogas slurry, high-sediment water and saline water increased by 3.4%, 17.5% and 93.1%, respectively. The flow coefficient decreased by 21.1%, 32.2% and 18.0%, respectively, while the flow index increased by 5.8%, 12.5% and 50.2%, respectively. Furthermore, the elastic modulus of the diaphragm decreased by 1.8%, 13.6% and 44.1%, respectively. These results underscored that chemical ions in the water source are the most critical factor influencing PCE performance, followed by sediment and organic matter, while microorganisms have a comparatively lesser impact. Furthermore, higher pressure levels were found to contribute to improvements in PCE performance. This study offers insights into the influence of various marginal waters on PCE performance, with implications for the broader adoption and implementation of pressure-compensating drip irrigation technology in conditions involving marginal water.