Effect of different sand filter underdrain designs on emitter clogging using reclaimed effluents

• Published in: Agricultural water management 2019-08, Vol.223, p.105683, Article 105683
• Main Authors: Solé-Torres, Carles, Puig-Bargués, Jaume, Duran-Ros, Miquel, Arbat, Gerard, Pujol, Joan, Ramírez de Cartagena, Francisco
• Format: Article
• Language: English
• Subjects: Filtration; Media filter; Microirrigation; Plugging; Wastewater
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2019.105683

•The effect of three sand filter underdrain design on emitter clogging was studied.•The experiment used a chlorinated reclaimed effluent and lasted 1000 h.•Clogging depended on the interaction between filter, time and emitter location.•Collector arm design achieved higher emitter discharge at 1000 h.•Percentage of completely clogged emitters did not depend on filter design. Sand media filters are those that achieve a higher retention of organic and inorganic solids, which is why they are usually recommended when reclaimed effluents are used in drip irrigation systems. Sand filters usually differ on the design of their underdrain, where an important pressure drop is produced. However, the effect of the design of sand filter underdrain on emitter clogging has not been widely studied. Three sand media filters with different underdrain designs (collector arms, inserted domes and drainage with porous media) were used for filtering a reclaimed effluent in a surface drip irrigation system. Pressure-compensating emitters with 2.3 l/h nominal emitter discharge were placed every 40 cm in 4 irrigation laterals each measuring 90 m in length. Effluents were chlorinated after being filtered. The filters operated for 1000 h with sand media heights of 20 and 30 cm and filtration velocities of 30 and 60 m/h. At the beginning, after 500 h, and at the end of the experiment the emitter discharge of each one of the 2712 emitters that were installed was experimentally measured under field conditions. On average, there was a statistically significant reduction (p