Severe Shortage and bad quality of Surface water in the area of Diyala Bridge , added to the growing demand for drinking , irrigation and sanitary waters , leads to study and qualify the under ground water in this area , Six shallow wells has been selected to the east of Diyala river , five of them where on shore and the sixth was far away from river about ( 3 km) .The depth of these wells was (10- 14)m . Tests of ( Ph , TDS , BOD , Turbidity , Conductivity ,----etc) where performed during March , June, Aug. in 2008. Heavy metals such as ( Pd , Zn , Cd , Fe , Mn ) has been examined as well . Results of physical , chemical and bacteriological tests show that the water quality of these wells were not comply with WHO requirements ,as well as results show considerable increased concentrations in TDS,BOD and heavy metals which indicates that underground waters were highly polluted with the sanitary waste waters . On the other hand the on shore wells' water quality was very close to the river water quality in comparison with the well in the middle of the town.
The current study includes application of QUAL2K model to predict the dissolved oxygen (DO) and Biochemical Oxygen Demand (BOD5) of lower reach of the Diyala River in a stretch of 16.90km using hydraulic and water quality data collected from Ministry of Water Resources for the period (January-April 2014). Google Earth and Arc-GIS technique were used in this study as supported tools to provide some QUAL2K input hydro-geometric data. The model parameters were calibrated for the dry flow period by trial and error until the simulated results agreed well with the observed data. The model performance was measured using different statistical criteria such as mean absolute error (MAE), root mean square error (RMSE) and relative error (RE). The results showed that the simulated values were in good agreement with the observed values. Model output for calibration showed that DO and CBOD concentration were not within the allowable limits for preserving the ecological health of the river with range values (2.51 - 4.80 mg/L) and (18.75 – 25.10 mg/L) respectively. Moreover, QUAL2K was used to simulate different scenarios (pollution loads modification, flow augmentation and local oxygenation) in order to manage the water quality during critical period (low flow), and to preserve the minimum requirement of DO concentration in the river. The scenarios results showed the pollution loads modification and local oxygenation are effective in raising DO levels. While flow augmentation does not give significant results in which the level of DO decrease even with reduction in the BOD5 for point sources. The combination of wastewater modification and local oxygenation (BOD5 of the discharged effluent from point sources should not exceed 15 mg/L and weir construction at critical positions 6.67km from the beginning of the study region with 1m height) is necessary to ensure minimum DO concentrations.
The present research focuses on the evaluation of the Tigris river water quality within the city of Baghdad. Thirty samples were collected monthly from ten sites (each site contains three positions center of river, Rasafa side, Karkh side) on the Tigris river within Baghdad city along one year (from Feb.2010 to Feb. 2011). Samples were analyzed for eleven water quality variables including physical, chemical, and biological parameters. The results showed increases in pH, TDS, TSS, Cl-1, SO4-2, and BOD values in some of the sites through study area, but all values remain within the allowable Iraqi and WHO limits except of SO4-2, it was exceeded the allowable limits in multiple sites.
In this paper three material with equal amount have been chosen to make a mixture, these materials are sand (passing sieve no. 1.18, porosity 0.41), activated carbon (passing sieve no. 4.75, porosity 0.51), crushed bricks (passing sieve no. 20, porosity 0.47), the mixture was used as a bio-filtering media , placed to a height of (1.15) m in a cylindrical filter with diameter of (300)mm and a height of (2)m which is designed and constructed from (PVC). The filter is equipped with three piezometers fixed at three point along the height of the cylindrical filter, in addition to three overflows at different height, and an outlet with control valve. On May 2010 the filter was operated with a synthetic wastewater similar to domestic sewage in order to determine the hydraulic and sanitary characteristics of the filter. Then the feeding of waste water was continued for 3 weeks in order to stimulate the growth of bio-film. On June 2010 the filter was operated with gray water to determine the change in filter characteristics after the bio-film growth, and to evaluate filter efficiency to treat this water for the purpose of reuse. The outcome of this work showed that the mixed media bio-filter, to a certain extent, is similar in hydraulic characteristics (pressure drop and hydraulic load) to granular activated carbon bio-filter, head loss at (1000) mm depth is (59%) of initial pressure, the growth of bio-film leads to increase in head loss by (43%), decrease in flow by (25|%), decrease in pressure by (16%). According to removal efficiency of pollutants, the results shows an efficient removal of BOD5 (86%), turbidity (96%), TDS (81%) at a retention time (60 minute).