The present work reports the performance of three types of polyethersulfone (PES) membrane in the removal of highly polluting and toxic lead Pb2+ and cadmium Cd2+ ions from a single salt. This study investigated the effect of operating variables, including pH, types of PES membrane, and feed concentration, on the separation process. The transport parameters and mass transfer coefficient (k) of the membranes were estimated using the combined film theory-solution-diffusion (CFSD), combined film theory-Spiegler-Kedem (CFSK), and combined film theory-finely-porous (CFFP) membrane transport models. Various parameters were used to estimate the enrichment factors, concentration polarization modulus, and Péclet number. The pH values significantly affected the permeation flux of the Pb2+ solution but only had a slight effect on the Cd2+ solution. However, Cd2+ rejection was highly improved by increasing the pH value. The rejection of the PES membranes increased greatly as the heavy metal concentration rose, while the heavy metal concentration moderately affected the permeation flux. The maximum rejection of Pb2+ in a single-salt solution was 99%, 97.5%, and 98% for a feed solution containing 10 mg Pb/L at pH 6, 6.2, and 5.7, for PES1, PES2, and PES3, respectively. The maximum rejection of Cd2+ in single-salt solutions was 78%, 50.2%, and 44% for a feed solution containing 10 mg Cd/L at pH 6.5, 6.2, and 6.5, for PES1, PES2, and PES3, respectively. The analysis of the experimental data using the CFSD, CFSK, and CFFP models showed a good agreement between the theoretical and experimental results. The effective membrane thickness and active skin layer thickness were evaluated using the CFFP model, indicating that the Péclet number is important for determining the mechanism of separation by diffusion.
This study deals with the conceptual rooting of the practical relationship between the practice of international public relations and popular diplomacy, as the latter sought - as a legitimate extension of traditional diplomacy - to involve foreign residents in international public relations capable of drawing a positive image of the state among people of other countries, by employing modern communication technology. Especially social media, which led to a shift from old diplomacy to digital public diplomacy. The research paper seeks to analyze the communicative content of the Facebook page (Israel in the Iraqi dialect), which a page is belonging to the "Israeli" Ministry of Foreign Affairs that aims, according to its messages, to encoura
... Show MorePseudomonas aeruginosa is an opportunistic pathogen. Quorum sensing (QS) is one of processes that are responsible for biofilm formation. P. aeruginosa can live in different environments, some of which are pathogenic (clinical isolates) and some that are found outside the body (environmental isolates). The present study aimed to determine the presence of a number of genes responsible for QS in clinical and environmental isolates of P. aeruginosa. In the present study full DNA was separated from all environmental and clinical isolates that contained seven genes (rhlA, rhlR, rhlI, lasR, lasI, lasB, phzA1) associated with QS occurrence. The tot
... Show MoreAbstract
This study is aim to :
- Put a standard to evaluate the altruistic behavior in kindergarten children.
- Know level of the altruistic behavior in the kindergarten children according to their mother "s points of view.
- Know the level of the altruistic behavior in the kindergarten children according to their teacher "s points of view.
- The differences in the level of altruistic behavior in kindergarten children between their mothers & teachers points of view.
The sample consists of (120) children of kindergarten children in Baghdad. The researcher has built a to
... Show MoreCloud computing is the new technological trend for future generations. It represents a new way to use IT resources more efficiently. Cloud computing is one of the most technological models for developing and exploiting infrastructure resources in the world. Under the cloud, the user no longer needs to look for major financing to purchase infrastructure equipment as companies, especially small and medium-sized ones, can get the equipment as a service, rather than buying it as a product. The idea of cloud computing dates back to the sixties of the last century, but this idea did not come into actual application until the beginning of the third millennium, at the hands of technology companies such as Apple, Hp, IBM, which had
... Show MoreThe conductance of solu ti ons of cysteine in water at different concentrations and temperatures has been measured. These solutions obey Onsagcr equation and give linear relations especially at low concentrations. In more concentrated solutions a deviation from the equation is observed.
The molar conductivity of these solutions decreases with t he increase in concen trations at constant temperature.
The values of the ionization constants and the conductivity at infin ite
dilution for each temperature have been calcu lated.
The purpose of the current research is to identify the most important problems that primary school students suffer from inside and outside the classroom from the point of view of their teachers. A sample of (100) male and female teachers was chosen from the Rusafa\ second Directorate for the academic year (2018-2019). The research tool was prepared after reviewing literature related to the issue of problems and difficulties facing students or students in the school stage and even at university. The researcher reached several results that were discussed in the fourth chapter, with a set of conclusions based on the results of the research, and come up with several recommendations and suggestions.
Absract
The letters of the Al-Safa Brothers contain many tales, in which each story is a literary text that is independent from the other texts, but it constitutes a unified entity in its entirety, because these stories contain recurring structural elements that go into building each one of them. The stories - the subject of the analysis - were not keen on something that was keen on adhering to the Sufi vision and its apparent effect on the tales of the messages, starting with the announcement of the narration to the narrator and his attempt to persuade the recipient of the truth of what is being told and its realism, and made him believe it. The stories correspond to the formal construction of the ideal style defined by th
... Show MoreUtilization of bacterial activity for decolorization of coloured products is one the most promising industrial strategy, as an eco-sustainable and cost-competitive alter-native to physicochemical methods. Laccase production from Bacillus sp. was stud-ied for its decolorization influences on different dyes (Indian ink, Brilliant green, Bromothymol blue, Crystal violet, Safranin, Bromophenol blue, Methelen blue, Giemsa stain, Nigrosin, Toluidin blue, Neutral red, Phenol red, Hanna, Blood, Ben-gal rose B, Bromkresol green, 4-Bromoaniline, Aniline blue, 2,6-Dichlorophenol in-vophenol, Curcumin, Acridine orange, Indigo carmine, Xylene cynol FF,10G, Aliza-rine yellow GG and Kongorose). After 5 days of incubation of the spore-bound lac-case wit
... Show MoreFive Saccharomyces cerevisiae isolated from the ability of chitinase production from the isolates were studied. Quantitative screening appeared that Saccharomyces cerevisiae S4 was the highest chitinase producer specific activity 1.9 unit/mg protein. The yeast was culture in liquid and solid state fermentation media (SSF). Different plant obstanases were used for (SSF) with the chitine, while liquid media contained chitine with the diffrented nitrogen source. The favorable condition for chitinase producers were incubated at 30 ºC at pH 6 and 1% colloidal chitine.
This study aims to identify the concepts of financial crisis and its reasons of creation , also explain the effects of the accounting disclosure and the International Accounting Standards in current financial crisis, In addition to, indicate the role of accounting in the reform of the financial system from the impact of financial crisis.
The methodology of this study orientied to two main aspects, the first is an identifying approach through exploring the opinion of financial experts, the second aspect is based on an analytical approach to satisfy the requirements of experts to get there opi
... Show More