Assessing dripper clogging and filtering performance using municipal wastewater

The paper discusses some drip irrigation system management problems according to the performance of emitters
and filters shown in six trials conducted in Sicily (Italy) using six kinds of municipal wastewater that has not
undergone previous advanced treatment. Nine types of filters (gravel media, disk and screen) and five types of drip
emitters (vortex, labyrinth and long-path) were tested. The performance of the emitters and filters tested depends
on the quality of the wastewater. Total suspended solids, BOD5 and pH are the water characteristics best correlated
to emitter and filter performance.
The vortex emitters tested were more sensitive to clogging than labyrinth emitters. The optimal performance of
the subsurface emitters shows the feasibility of drip subirrigation. The gravel media filters guaranteed the best
performance. The disk filters, which are cheaper and simpler to manage, assured satisfactory performance in most
trials. Screen filters were shown to be unsuitable for use with wastewater of poor quality. The need for frequent
cleanings leads to short operating times for the filters, which may cause management problems. An empirical
equation is proposed to estimate the frequency of filter cleaning operations depending on the solid discharge.