ASABE Technical Library - Abstract

Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, view access and subscription options

CLOGGING INCIDENCE OF DRIP IRRIGATION EMITTERS DISTRIBUTING EFFLUENTS OF DIFFERING LEVELS OF TREATMENT

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org

Citation:  Paper number  701P0104,  . (doi: 10.13031/2013.15764)
Authors:   M. Rowan, K. Mancl, O. H. Tuovinen
Keywords:   Biofilms, Clogging, Drip/Trickle irrigation, Emitter, On-site wastewater treatment, Sand bioreactor, Septic tank, Sewage sludge

Four types of drip irrigation emitters from three manufacturers were used to distribute effluents of different qualities. The control emitters were embedded in commercial grade landscape dripline, which was not designed for use with treated wastewater. The experimental emitters included one non-pressure compensating, turbulent flow emitter and two pressure compensating diaphragm regulated emitters. The experimental emitters were specifically designed for use with treated wastewater and contained antimicrobial agents to prevent emitter clogging. The emitters distributed tap water, primary septic tank effluent and secondary sand bioreactor effluent. All three effluents were run through a 100-micron filter. Each effluent was distributed through each emitter type for ten minutes every six hours, seven days a week for twelve months. Emitter flow rates were measured each month to evaluate system performance and identify clogged emitters. The control emitters exhibited the greatest reduction in flow rates with an average reduction of 16% for septic tank effluent and 3% for sand bioreactor effluent. With experimental emitters, the average flow rates were reduced by as much as 11% for septic tank effluent and 2% for sand bioreactor effluent. By the end of the experiment, many of the clogged emitters had recovered to near their original flow rates. The emitters distributing the septic tank effluent exhibited the most significant reduction in flow, with a maximum of 80% in the most severely restricted experimental emitter. The sand bioreactor, which reduced the effluent 5-day biochemical oxygen demand from 147 mg/l to 0.5 mg/l and total suspended solids from 55 mg/l to 3 mg/l, also reduced the degree of clogging in all four types of emitters. After one year of use, the control emitters distributing primary septic tank effluent showed the greatest amount of clogging. The three driplines designed for irrigating wastewater were functioning as designed.

(Download PDF)    (Export to EndNotes)