Modeling selected water quality parameters at Jebel Ali Harbour, Dubai- UAE

Jebel Ali Free Zone in Dubai has the largest man-made harbour in the world. Several factors may affect water quality in the harbour, including discharge of treated wastewater, navigational activities, and nearby projects in the Arabian Gulf. The main objective of this study was to simulate the level of BOD and some nutrients in the harbour water under existing and potential future conditions. Modeling of water quality was carried out using the ECO Lab coupled with the advection-dispersion modules in the MIKE21 modeling system. The results showed that the input rates of BOD, ammonia, nitrate and phosphate associated with the discharged treated wastewater are not sufficient to simulate the observed levels of these parameters in the harbour water. Additional input rates of 600 times for BOD and 144 times for nitrate are needed to adequately describe the observed levels of these parameters. An assimilation capacity analysis of BOD in the harbour water revealed that the BOD starts to build up when the BOD loading rate reaches 2.88 g/m²/d, which is about 20% higher than the estimated loading rate under the current conditions. Simulations further showed that increasing the organic loading into the harbour will reduce DO and increase ammonia, but will not significantly affect nitrate and phosphate levels in the harbour water.