Effect of drip irrigation with reclaimed water on emitter clogging

A laboratory experiment was conducted to investigate the mean discharge, distribution uniformity coefficient and clogging pattern of the single wing labyrinth emitter, the integral labyrinth emitter and the pressure-compensation emitter with the application of tape water and reclaimed water. Main reasons of emitter clogging were analyzed. Results indicated that the mean discharge and Christiansen uniformity coefficient of the three types of emitters were obviously lower for reclaimed water in comparison with those for tap water. The reduction percentages of the mean discharge and distribution uniformity coefficient were the greatest for the single wing labyrinth emitter, while the least were for the pressure-compensation emitter. Chemical precipitation (main parts: CaCO3 and MgCO3) was the main reason for emitter clogging, which was partially due to higher ions concentration and pH value for the reclaimed water in comparison with the tap water. Emitters with low discharge, small flow-path dimension and higher emitter discharge exponent were also subject to clogging. The pressure-compensation emitter is recommended for drip irrigation system with the application of reclaimed water.