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.
The present paper concerns with the problem of estimating the reliability system in the stress – strength model under the consideration non identical and independent of stress and strength and follows Lomax Distribution. Various shrinkage estimation methods were employed in this context depend on Maximum likelihood, Moment Method and shrinkage weight factors based on Monte Carlo Simulation. Comparisons among the suggested estimation methods have been made using the mean absolute percentage error criteria depend on MATLAB program.
Arabic language the timeless language of the Qur'an ((I made it read Arabic you may understand)) (Al-Zukhruf No 3). It is a way to express his thoughts and feelings and capable of giving constant absorbed the needs of the times and meet the General requirements and interactive needs of life to achieve social and intellectual aspects.
The aim of current research to identify what teaching the contemporary trends in teaching, what the nature of knowledge and teaching methods, how do you rate the modern Arabic language teaching methods, the criteria for evaluating the effectiveness of teaching where the researcher has reached some recommendations: 1. establish the basics of environmental ed
... Show MoreThis review focuses on conservation agriculture (CA) and its effects on increasing the soil’s resistance to erosion. CA involves minimum soil disturbance (minimum tillage/ no-till), diversified crop rotation, and maintenance of the soil cover to increase soil fertility and reduce erosion. CA reduces soil loss by up to 90% and water erosion by approximately 50 to 70% from runoff as it increases the health of the soil, yield of crops, and water-retention capacity of the soil by incorporating soil organic matter and promoting biodiversity. Crop rotation prevents the replenishment and depletion of soil nutrients by atmospheric fixation of nitrogen/biological nitrogen fixation. Controlled traffic farming (CTF) is a new strategy in which travel
... Show MoreThe current study tackles how slavery and racial segregation, which have obviously made an enormous impact in the United States of America for many years, can be defeated through optimism. The study opens with an introduction that clarifies some background about Langston Hughes as a poet who writes against slavery and oppression done to the American Blacks during an era which was known for racial segregation in the United States of America. The poet sheds light , in his poetry, upon the role of African Americans in activating hope and optimism to get freedom which has been reached at the end. The first section of the study analyzes the meaning of slavery and segregation as reflected in some selected poems, showing the oppressive face of
... Show MoreDiabetes mellitus is a multifaceted, chronic disease that happens either when the pancreas does not produce enough insulin or when the human body cannot competently use the insulin it produces. The study was aimed to determine and show the ultrastructural changes of cells in the placenta of women suffering from diabetes mellitus disease. In this study, a total of 102 placentas were investigated by transmission electron microscopy, which includes 34 placentas with gestational diabetes, 34 placentas with pregestational diabetes, and 34 placentas with normal pregnancy as a control group. Placental vascular-syncytial membrane, trophoblastic basement membrane, villous stroma, and fetal vessel were investigated for their thickening basement membr
... Show MoreBackground: Brucellosis (Malta fever) is one of the zoonotic diseases that endemic in all the world, this disease has a history from 1937 in Iraq when the microorganism was first isolated via an Iraqi clinician.Objective: To demonstrate brucellosis infection among Iraqi provinces and reveal relationship between Brucellosis with seasons, residence place, gender and age of the patients. In addition to diagnosis of brucellosis from patients in Baghdad province suspects of infection by serological methods (Rose Bengal test) and culture method in diagnosis of brucellosis in human.Patients and Methods: This cross sectional study was conducted at Iraqi hospitals in different Iraqi provinces. The blood sample (serum) was obtained from 1825
... Show MoreIn this study, 191 specimens of insects that infect species of the Fabaceae family, including: