DEVELOPMENT AND EVALUATION OF AN ALTERNATE MEDIA FILTER FOR DRIP IRRIGATION SYSTEM

Abstract

In areas where water is scarce, drip irrigation provides the most efficient way to conserve irrigation water. The performance of drip irrigation systems using waste water is mainly limited by emitter clogging and these discourages farmers from introducing it. Even though different filters such as screen filter, disc filters, hydro cyclone filter etc. are available in market, the deciding factor is the price at which it is available. Also, the farmers in rural areas can’t afford the high cost of these filters. So, this study focusses on development and evaluation of an alternate media filter for drip irrigation system. This study was conducted at an open field in front of hydraulics lab KCAET, Tavanur. The designed PVC filter system consist of two chambers, primary chamber and secondary chamber. Two experiments were done by changing the filter media. In first experiment, primary chamber was filled with clay roof tile, metal stone and gravel and secondary chamber was filled with charcoal, metal chips and gravel. In second experiment, the primary chamber was filled with gravel, silex sand and fine sand and secondary chamber media were kept same. The efficiency of filter increased from 50 - 63% to 75 - 88% when sand is incorporated as the media. The TSS removal varied from 0.12 to 0.2 g/l for the 1st experiment and 0.12 to 0.28 g/l for the 2nd experiment. Hence, second experiment filter was found more efficient than first experiment filter. From the evaluation of the filter, it was observed that the discharge from the filter increases as the time increases. Also, pressure drop and discharge increases linearly. Electrical conductivity and pH were at acceptable range (5.5 to 8.4). While testing of filter for emitter flow, it was observed that each emitter gave almost uniform discharge at various pressure. Hence this filter can be recommended to reduce cost of drip system and preferred for rural areas in small scale farm applications.