This study focused on treatment of real wastewater rejected from leather industry in Al-Nahrawan city in Iraq by Electrocoagulation (EC) process followed by Reverse Osmosis (RO) process. The successive treatment was applied due to high concentration of Cr3+ ions (about 1600 ppm) rejected in wastewater of this industry and for applying EC with moderate power consumption and better results of produced water. In Electrocoagulation process (EC), the effect of NaCl concentration (1.5, 3 g/l), current density (C.D.) (15-25 mA/cm2), electrolysis time (1-2 h), and distance between electrodes (E.D.) (1-2 cm) were examined in a batch cell by implementing Taguchi experimental design. According to the results obtained from multiple regression and signal to noise ratio (S/N), the optimum conditions for the best removal of Cr3+ ions were, 1.5 g/l of NaCl, 25 mA/cm2 of C.D., 2 h of electrolysis time, and 1.5 cm of distance between electrodes. Also, the analysis of variance (ANOVA) indicates that the percentage of contribution followed the order: C.D. (47.26 %), time (15.56 %), NaCl conc. (13.81 %), and E.D. (5.67%). The results of multiple regression model gave R2= 88.41 % which can be considered as an acceptable agreement between predicted and experimental values. Results of confirmation test revealed that the removal efficiency of Cr3+ ions at optimum conditions was 88.80 %. The final collected solution from EC process was treated with RO process in which the effect of applied pressure and feed flowrate were investigated. Experimental results revealed that the highest values of Cr3+ Re% in permeate was 99.89 %.
Background: The main purpose of this study is to find if there is any correlation between the level of C-reactive protein (CRP) in gingival crevicular fluid with its serum level in chronic periodontitis patients and to explore the differences between them according to the probing depth. Materials and methods: Forty seven male subjects enrolled in this study. Thirty males with chronic periodontitis considered as study group whom further subdivided according to probing depth into subgroup 1 with pocket depth ≤6mm, subgroup 2 with pocket depth >6mm. The other 17 subjects considered as controls. For all subjects, clinical examination where done for periodontal parameters plaque index (PLI), gingival index (GI), bleeding on probing (BOP),
... Show MoreThis study investigates the performance of granular dead anaerobic sludge (GDAS) bio-sorbent as permeable reactive barrier in removing phenol from a simulated contaminated shallow groundwater. Batch tests have been performed to characterize the equilibrium sorption properties of the GDAS and sandy soil in phenol-containing aqueous solutions. The results of GDAS tests proved that the best values of operating parameters, which achieve the maximum removal efficiency of phenol (=85%), at equilibrium contact time (=3 hr), initial pH of the solution (=5), initial phenol concentration (=50 mg/l), GDAS dosage (=0.5 g/100 ml), and agitation speed (=250 rpm). Fourier transform infrared (FTIR) analysis proved that the carboxylic acid, aromatic, alk
... Show MoreCadmium element is one of the group IIB and classified as heavy metal and effects on human health and environment. The present work concerns with the biosorption of Cd(II) ions from aqueous solution using the outer layer of onions. Adsorption of the used ions was found to be pH dependent and maximum removal of the ions by outer layer of onions and was found to be 99.7%.
Abstract
The Non - Homogeneous Poisson process is considered as one of the statistical subjects which had an importance in other sciences and a large application in different areas as waiting raws and rectifiable systems method , computer and communication systems and the theory of reliability and many other, also it used in modeling the phenomenon that occurred by unfixed way over time (all events that changed by time).
This research deals with some of the basic concepts that are related to the Non - Homogeneous Poisson process , This research carried out two models of the Non - Homogeneous Poisson process which are the power law model , and Musa –okumto , to estimate th
... Show MoreIn this study involves removing of Brilliant Dyes, were which (Brilliant Green {BG} and Brilliant Cresyl Blue {BCB}) by using Iraqi Siliceous Rocks Powder (SRP). Adsorption isotherms were studied and the factors which prefer it, like temperature and salt effect, Adsorption isotherms of dyes, Brilliant Cresyl Blue {BCB} was found to be comparable to Langmuir equation according to Giles classification, isotherms dye Brilliant Green {BG} was found to be comparable to Freundlich equation more than dye Brilliant Blue {BCB} according to Giles classification. The adsorption process on this surface (SRP) studied at different temperatures, the results showed that the adsorption of dyes (BCB, BG) on the surface increased with increased temperature (E
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