ABSTRACT
Water and Well Water ........................................................114 4.2.3 Specifications of Drip Irrigation System ...........................114 4.2.4 Criteria for Assessment of Emitter Performance ..............116 4.2.4.1 The Reduction of Main Discharge
Qreduction Percent .............................................116 4.2.4.2 Manufacturer’s Coefficient of
Emitter Variation (CV) .......................................118 4.2.4.3 Field Emission Uniformity
Coefficient, EU (%) ............................................118 4.2.4.4 Dripper Exponent (x) .........................................119 4.2.4.5 Emitter Flow Variation (qvar) ............................119 4.3 Results and Discussion ................................................................ 120 4.3.1 Water Quality ................................................................... 120 4.3.2 Mean Discharge Reduction .............................................. 121
4.3.3 Effects of DTSW and WW Treatments and Emitter Type on Partial and Total Clogging of Emitters ............... 121
4.3.4 Effects of DTSW and WW Treatments on Partial Filter Clogging Percentage ............................................... 121
4.3.5 Mean Discharge Reduction Percentage for Different Types of Filters ................................................. 123
4.3.6 Field Emission Uniformity Coefficient ............................ 124 4.3.7 Influence of the DTSW and WW Characteristic
on Performance of Emitters and Filters ........................... 124 4.4 Conclusions .................................................................................. 125 4.5 Summary ...................................................................................... 125 Keywords .............................................................................................. 126 References ............................................................................................. 127
4.1 INTRODUCTION
Agricultural water demand with conventional resources, using treated waste water represents a viable option [6, 9]. Emitter clogging hazards are major considerations in selecting drip irrigation systems for use with water from open reservoirs, and particularly from that storing secondary treated sewage water. Most clogging factors and agents can be found in these waters [5, 12]. Reservoir water contains a variety of phytoplankton and zooplankton that develop during storage according to the specific conditions prevailing in the reservoir. Suspended particles, which can agglomerate with filaments, slimy or otherwise sticky by-products of microbial activity, are also abundant, especially in earthen reservoirs [14]. There are also aquatic organisms that can grow and proliferate within the pipeline system and, in certain circumstances can develop into a biomass that can clog almost any component of the drip irrigation system [12, 14]. Such problems might be intensified by longer supply lines and slower stream velocities. The nutrients and organic matter brought into the reservoir with wastewater effluent will enhance algae bloom, particularly the slimy blue algae species. Microbial activity in deeper layers increases in reservoirs storing sewage effluent.
