水保所知识产出(1956---)知识库

Emitter clogging negatively affects the performance of subsurface drip irrigation systems. The porous ceramic
emitters of a subsurface irrigation system were investigated to identify the reasons for emitters clogging. Using 2-
year operational data in an apple orchard, the soil water content and the emitters discharge were measured, the
position and composition of the clogging substance were investigated, and the thickness of the adhesion layer in
the channel of the emitter was calculated. Further, a flushing experiment using acid water with a pH of 6 was
carried out to assess emitter clogging. The primary reason for the emitter clogging was substances precipitated at
the inlet of the emitter, resulting in reducing the discharge of the emitter. At the same time, the water flow was
affected by the clogging substance inside the micropore close to the channels. The main compounds of the
clogging substances were SiO 2 , CaCO 3, and MgAl 2 O 4. Fe, Cl and K were also observed. Bacteria, fungus and
microalgae secreted PLFAs to form biofilm. We have tested 4 flushing times (3 min, 10 min, 15 min, 20 min) and
found that when the flushing time lasted 15 min, the corresponding emitter discharge were 0.046 L h −1 and
0.136 L h −1 under the working pressure of 2 kPa and 5 kPa, and discharge recovery rate were 51.11% and
75.56%, respectively. However, when the flushing time increased to 20 min, the discharge recovery was similar
to that of 15 min. Therefore, it is recommended to flush with an acid solution for 15 min at flushing pressure of
100 kPa pressure to minimize the emitter clogging.