Evaluation of Drip Irrigation Emitters Distributing Primary and Secondary Wastewater Effluents (original) (raw)

Emitters and filters performance for sewage water reuse with drip irrigation

2010

Increasing urbanization in India is generating huge quantities of wastewater resulting in several environmental problems. Thus, use and dispose approach has to be dispensed with for use and reuse approach. Agriculture, a major consumer of good quality water, could be one sector to consume such marginal quality waters. Although surface irrigation is widely used for irrigation with waste water, drip irrigation could be suitable for sewage water reuse as it minimises the health risk to the farmers (avoids direct contact both of the person and the produce) and consumers. Since emitters and filter clogging would limit the performance of drip irrigation system, it might discourage the farmers from lapping up this technology. This paper gives a brief overview of the results of experimental trials for using sewage water on the behaviour of two kinds of filters i.e. sand and screen filters attached in series and using labyrinth type of emitters, considered most suitable against clogging. The performance of the filters recommended for clean water was inadequate for sewage water (suspended solid 100 mg l-1 and BOD ranging from 45-200 mg l-1). The operating time of the filters between cleaning operations in the case of screen filter was less than one hour causing inconvenience in operations while in the case of sand filter head losses increased from 3.1 m to 7.9 m. Clogging of the filters caused inconvenience in irrigation and energy loss went up to 100%, thus increasing input cost. The results also revealed that reduction in flow rate of the emitters was only 0.5% in the case of surface drippers, which increased to 12% in the case of subsurface drip irrigation. The coefficient of variation increased from an initial value of 0.08 to 0.16 for surface and from 0.08 to 0.23 for subsurface drip irrigation. As it is expected, clogging resulted in reduced application efficiency and reduction was from its initial value of 92 to 85% and 72% in the case of surface and subsurface drip irrigation, respectively.

Dripper clogging: emphasis on the problem and how to minimize impact

Revista Brasileira de Engenharia de Biossistemas

Irrigation is a useful tool to achieve a better productivity and quality foods, which contributes to a higher efficient use of agriculture land. Drip irrigation is characterized by higher application efficiency, providing an efficient control of the irrigation depth required. Moreover, it has advantages such as lower evaporation loss and higher crop yields when associated with fertigation. However, dripper clogging is pointed out by several authors as the main limiting factor for a rapid adoption of drip irrigation on a larger scale. Emitter clogging susceptibility depends basically on five parameters: water quality, filtration system, fertilizer quality, labyrinth architectural layout and maintenance procedures. The adoption of chemical treatments helps to control biological agents and precipitates, making it possible to minimize the risk of clogging. This paper aims to understand how drip clogging process occurs, providing scientific arguments and support on the development of a s...

Effect of flushing frequency on emitter clogging in surface and subsurface drip irrigation

2010

The effect of three dripline flushing frequency treatments (no flushing, one flushing at the end of each irrigation period, and a monthly flushing during the irrigation period) was studied in surface and subsurface drip irrigation systems that operated using an effluent for three irrigation periods of 540 h each. The irrigation systems had two different emitters, one pressure compensating and the other not, placed in laterals 87 metres long. Dripline flow of the pressure compensating emitter increased 8% over time, while in the nonpressure compensating emitter, dripline flow increased 25% in the surface driplines and decreased 3% in the subsurface driplines by the emitter clogging. Emitter clogging was affected primarily by the interactions between emitter location, emitter type, and flushing frequency treatment. The number of completely clogged emitters was affected by the interaction between irrigation system and emitter type. There was an average of 3.7% less totally clogged emit...