Abstract
Reclaimed water (RW) is a reliable alternative water supply for irrigation in the agricultural sector, which is the predominant consumer of water in Iraq. A mixed-integer nonlinear programming reclaimed water allocation optimization model was developed to maximize the net benefit generated from the cultivation of different types of crops, comparing the use of reclaimed water type A (tertiary treated water), and reclaimed water type B (secondary treated water). The model was solved using the Algorithms for coNTinuous/Integer Global Optimization of Nonlinear Equations (ANTIGONE) optimizer in the general algebraic modeling system (GAMS). A total of 84 agricultural farms located on 5300 ha to the south of Baghdad, Iraq were available for irrigation with reclaimed water. Analysis considered varying quantities of available reclaimed water and different irrigation efficiencies (45–85%). The net benefits from using lower quantities of reclaimed water were similar for both types of reclaimed water, and the highest net benefit crop was cultivated on 384 ha. As the quantities of water increased, the amount of cultivated land increased and the net benefit per hectare decreased as the model required the cultivation of more crops with lower economic value. Irrigation with reclaimed water has potential to increase agricultural and economic activity adjacent to Baghdad.
Highlights
Mesopotamia, present day Iraq, has been proud of its abundance of water in the Tigris and the Euphrates Rivers which has historically enabled the development of a vibrant civilization and economy
Utilization of the treated wastewater for agricultural irrigation has the potential to improve water quality in the river and to further develop the local agricultural economy. Both the Karkh and the Rustumia wastewater treatment plants (WWTPs) provide secondary treatment for their influent and plans to implement tertiary treatment have been made, recognizing the need for further treatment for agricultural reuse. In this water allocation optimization model, reclaimed water type A (RWA ), and reclaimed water type B (RWB ) are to be allocated on a total of 84 farms with a total area of 5300 ha to the south of Baghdad allowing up to four crops to be cultivated in each farm
With an increase in irrigation efficiency using a specific quantity of water, the computed net benefit per cultivated hectare of crops increased until a limit was reached
Summary
Mesopotamia, present day Iraq, has been proud of its abundance of water in the Tigris and the Euphrates Rivers which has historically enabled the development of a vibrant civilization and economy. In Baghdad, there is secondary treated wastewater of more than 1.0 MCM that is discharged to the Tigris River These large quantities of treated wastewater contribute to the pollution of the receiving waters. Optimization Navigator (BARON) [4], the Basic Open-source Nonlinear Mixed Integer (BONMIN) [5], the Convex Over and Under ENvelopes for Nonlinear Estimation (COUENNE) [6], and the DIscrete and Continuous OPTimizer (DICOPT) [7], were investigated for solving the MINLP problem In this MINLP water allocation optimization model, reclaimed water was allocated proportionally on farms where each farm’s water share was equal to the ratio of its agricultural area to the total agricultural area of all farms. Reclaimed water availability and the cultivated area form the main constraints in this model in addition to the farm–crop connectivity, farm–RW connectivity, and minimum net benefit constraints
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
