Emitter clogging in a reclaimed water irrigation scheme with controlled suspended load

Abstract

Emitter clogging in drip irrigation system is a very common problem when used with reclaimed water. The suspended solids from treated water are the major elements of clogging mechanism. Coupled with bacterial biofi lms, these particulates can reduce the fl ow of emitters by creating barriers in the fl ow path. This experimental study reports the performance of three types of pressure compensated emitters in a drip irrigation system. Reclaimed water with a sediment load of 10 mg/l was supplied in the system throughout the experiment. Four ranges of particle sizes (0-45, 45-90, 90-150, and 150-300 μm) were used during 770 h of intermittent irrigation. Low fl ow emitters (<2 l/h) were found to be clogged quicker than those with higher fl ow rates. Though fl ushing of the system did not help in discharge recovery of the partially clogged emitters, it helped regain the lateral fl ow. The interior geometry of biofi lms was found to be built only by the smaller particles. Larger particles (>50 μm) only appeared around the perimeters of matured biofi lms making the surface topography very coarse and undulating.