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Go to Editorial ManagerShatt Al-Arab River is the main water source for all water treatment plants in Basrah governorate. In order to assess its suitability as a source for domestic water supply and the performance of some of main water treatment plants, water quality index (WQI) is obtained for both raw and treated water for 10 water treatment plants. Physic-chemical parameters were monitored for the calculation of WQI for Winter, Spring, Summer, and Autumn seasons from March- 2011 to March- 2012.The parameter which were taken into account for the present work are pH, turbidity, electric conductivity, total alkalinity, total hardness, Ca, Mg, Cl, SO4, TDS, Na, and K. The results indicate that Shatt Al Arab is very poor for domestic, industrial, and irrigation purposes during Winter, Spring, Summer, and Autumn seasons, while seven of ten of consider of water treatment plants produce water of poor quality.
Supplying drinking water in Al-Dewanyia city to meet Iraqi Drinking Water Guidelines is a challenge as source waters contain high concentrations of Natural Organic Matter (NOM) that often exceed 12 mg/L Dissolved Organic Carbon (DOC). The US EPA indicates that enhanced coagulation is the best available technology to control DOC in drinking water treatment plants. A water director of Al-Qadissiya has used enhanced coagulation at Al-Dewanyia Water Treatment Plants (WTP’s) in Iraq since 2004 to improve water quality in the distribution system. NOM reduction has led to treated water with a lower chlorine demand allowing a greater residual penetration enabling improved bacteriological compliance. Since the cost of DOC (and Disinfection by-product DBPs) determination was high, it was decided to study the traditional analysis of COD as a surrogate measure to detect the organic constituents in raw water and the extent to which optimized coagulation with ferric chloride can increase COD removal. The water samples studied belonged to Al-Dewanyia River. For samples the observed values of COD removal by coagulation at lower pH (about 1-1.5 pH values less than the regular pH (5.8 ~ 8.5)) were about 85-95 percent without making water turbidity unacceptable. In order to determine the effects of organic content on coagulation, The results indicated that a modified coagulation process without need to much increasing the amount of coagulant can be developed for these water samples.
A part of Basra water network which is near to Bradia water treatment plant is analyzed by using water cad program, water cad is also used for studying the water quality in the model by calculating the age and chlorine concentration for each pipe on the model. This model consist of (21)pipe ,(15)node or junction ,(6)loops, two water pumps one is operated and the second is stand by(each pump has a discharge equal to 0.6 mP3P/sec and a head of 60 m and an electrical control which related with the elevation of water in the tank),one elevated tank &one reservoir of water. The model studied hydraulically for two cases, the first case when the pump is power on and the second case when the pump is power off. Also the direction and discharge for each pipe are calculated. Different results are obtained in two cases. Also the results of water quality studies show that both the age of water and chlorine concentration at any pipe depended on its location with respect to the water treatment plant. Finally the calibration of the model is done in order to check the accuracy of the results.
The current approach to cooling water treatment is to use a multi – component inhibitors. Cooling water formulations containing mixtures of inhibitors usually offer better and increased protection to ferrous metals than similar concentrations of either of the individual components. Such mixtures are synergistic in their action .But; the synergistic effects between nitrites, molybdates and inorganic phosphate were not investigated until recently. A weight loss technique was used to investigate such mixture and to optimize the concentrations of the components in the blend.Consequently; an efficient and effective blend was developed as a corrosion inhibitor for carbon steel in aerated Al–Daura refinery re-circulating cooling water in the pH range 6.75 to 7.25. The preferred concentrations of components in the multi- component inhibitor blend (as ppm ) were: (SN + SM): SHMP = 800: 20 with SN: SM weight ratio =3:2.The reduction in corrosion rate was 97.6 % .
Failures in the steam tubes of boiler furnaces in Najebia power plant was studied experimentally. Visual examination, mechanical tests, microscopic test and chemical analyses were performed. Visual examination showed the types of failure in the tubes. Tensile and hardness tests were performed to estimate the variation in the mechanical properties of the tubes metal and compared with the new tubes. Microscopic test for the failed tubes used to recognize the difference in the microstructure to the metal of the tubes. Chemical analyses involved chemical composition of the tubes metal, river and feed water analyses, water treatment, fuel analyses and analysis of deposits and oxides on the external and internal sides. Overheating and wall thinning of the tubes resulted from oxygen escaping to the inner side of these tubes, and presence of deposits and oxides on the external and internal sides which led to failure was studied extensively. Engineering remedies were also given to confine the problem and to prevent it in future.
Flocculation process is used to agglomerate colloids to form large and heavy flocs. It is accomplished using mechanical or hydraulic slow mixing. The hydraulic mixing is usually achieved using baffles. The aim of this study is to conduct experimental work to study the effect of baffles shape and configuration on baffled flocculator performance. The work includes 304 experiments conducted in a pilot plant of baffled flocculator. Two arrangements of three baffle shapes (blind baffles, baffles of rectangular slot and baffles of circular slots) were adopted. During each experiment, water turbidity and temperature, influent flow rate and head loss were measured. The main outcomes of this study are; (1) for all baffle types and arrangements, flocculation efficiency (FE) increases with the increase of velocity gradient (G) till it reaches a maximum value, then, it decreases and the G value which produces the maximum FE varies with detention time (t), (2) within the applied range of Gt values (10231-25304), the correlation between FE and Gt is weak to moderate positive and varied according to baffles type and arrangement, (3) within the applied range of initial water turbidity (IWT) values (18.1-196) NTU, the correlation between FE and IWT is weak positive to good positive represented by logarithmic relationship, and (4) within the implemented baffle types, the blind baffles type gives the highest FE values for all the baffles number as compared with the other baffle types. Also, the most frequent head loss coefficient values were obtained.