The Value of a Constructed Wetland in Southern Iraq to Sustainably Enhance Water Quality

摘要

To enhance the living conditions of Southern Iraq, the efficient use of water resources is critical. Large and unsustainable irrigation projects have reallocated water resources and infrastructure has been developed without consideration of the serious damage to the ecological health of the Mesopotamian wetlands. Agricultural, environmental, and domestic pressures not only consumed fresh water resources, but they also released contaminated waters back to drainage systems. Reuse of this water would have great value to the region. In coordination with Nature Iraq, an Iraqi nongovernmental organization focused on the protection and restoration of the environment of Iraq, we have designed and proposed to build a 0.45 km~2-constructed wetland to effectively improve and sustain water quality in the region. The constructed wetland, which is designed to address water quality problems in Iraq's Main Outfall Drain (MOD), will be engineered to imitate and enhance the natural cleansing functions performed by natural wetland ecosystems. We have developed a model to predict the efficacy of chemical removal for a variety of chemical contaminants. This model predicts that we can remove approximately 90% of biochemical oxygen demand (BOD), 75% of the total nitrogen, and approximately 50% of the total phosphorous. The constructed wetland will allow the reuse of approximately 10-20 m~3/s of the MOD water. This diversion will reduce electricity requirements for the three large pumps that were built to bypass water at the MOD-Euphrates River intersection by 10-20%.