In this study, low cost biosorbent ̶inactive biomass (IB) granules (dp=0.433mm) taken from drying beds of Al-Rustomia Wastewater Treatment Plant, Baghdad-Iraq were used for investigating the optimum conditions of Pb(II), Cu(II), and Ni(II) biosorption from aqueous solutions. Various physico-chemical parameters such as initial metal ion concentration (50 to 200 mg/l), equilibrium time (0-180 min), pH (2-9), agitation speed (50-200 rpm), particles size (0.433 mm), and adsorbent dosage (0.05-1 g/100 ml) were studied. Six mathematical models describing the biosorption equilibrium and isotherm constants were tested to find the maximum uptake capacities: Langmuir, Freundlich, Redlich–Peterson, Sips, Khan, and Toth models. The best fit to the Pb(II) and Ni(II) biosorption results was obtained by Langmuir model with maximum uptake capacities of 52.76 and 36.97 mg/g for these two ions respectively. While for Cu(II) the corresponding value was 38.07 mg/g obtained with Khan model. The kinetic study demonstrated that the optimum agitation speed was 400 rpm, at which the best removal efficiency and/or minimum surface mass transfer resistance (MSMTR) was achieved. A pseudosecond-order rate kinetic model gave the best fit to the experimental data (R 2 = 0.99), resulting in mass transfer coefficient values of 42.84×10−5, 1.57×10−5 , and 2.85×10−5 m/s for Pb(II), Cu(II), and Ni(II) respectively. The thermodynamic study showed that the biosorption process was spontaneous and exothermic in nature.
إن موضوع الشرق الأوسط بشكل عام اتخذ أهمية كبيرة في الكتابات والمؤلفات التي صدرت منذ بداية النصف الأول من عقد التسعينات من القرن المنصرم مع بدايات مشاريع السلام التي أعقبت انهيار الاتحاد السوفيتي وتغير الخارطة السياسية والاقتصادية والايديولوجية للعالم .وعلى الرغم ان المصطلح ليس بجديد الا ان تعابير المصطلح وددلالاته تتغير مع تغير موازين القوى واتجاهات المصالح. إذ انتقل من مصطلح جغرافي الى
... Show More
Soil is the cardinal resource for agricultural crops. Healthy soil will produce healthy plants. Since healthy soil is the important goal for the farmers, they need to select the best tillage system to achieve that goal. There are two main types of tillage systems. Conservation tillage (no-tillage farming) uses agricultural machinery that performs a double function; tillage and seed farming simultaneously. In contrast, conventional tillage farming uses multiple agricultural machines to till and seed the soil. The farmers in the northern governorates of Iraq have used the conservation farming system for a long time. However, the farmers who live in the middle and southern governorates in Iraq use conventional tillage farming. Because most of
... Show More
(3)
(14)
(3)
(13)
(12)
(13)
(1)
The study of these selected traces shows that what Imam Mardini did on Imam al-Zayla'i and enabled him to graduate the hadiths of the book (guidance and conclusions) as well as in choosing the novel closest to Murad the work and not as described by al-Zayla'i .... never deserves descriptions.
In this article we study a single stochastic process model for the evaluate the assets pricing and stock.,On of the models le'vy . depending on the so –called Brownian subordinate as it has been depending on the so-called Normal Inverse Gaussian (NIG). this article aims as the estimate that the parameters of his model using my way (MME,MLE) and then employ those estimate of the parameters is the study of stock returns and evaluate asset pricing for both the united Bank and Bank of North which their data were taken from the Iraq stock Exchange.
which showed the results to a preference MLE on MME based on the standard of comparison the average square e
... Show More
The study examines Julia Alvarez's role as a Dominican American author, poet, and essayist. Despite being born in New York City in 1950, she was raised in the Dominican Republic by a family with Dominican heritage. Her residence in her ancestral homeland significantly influenced her subsequent literary works. Upon her father's implication in a conspiracy against Dominican President, he departed from the Dominican Republic. Alvarez encountered the challenge of the English language. They were compelled to acquire proficiency in English due to the prevailing perception that anyone who spoke a language other than English were deemed "un-American" during that period. Alvarez recounted her initial encounters in the United States and the subseque
... Show MoreTHE ACTUAL SOCIETY MODEL
Our society model has been showing signs of exhaustion since the end of the XX century. The recent appearance of the Covid-19 virus is another consequence of humanity's distance from Nature and the environment it inhabits. Also, climate change, environmental deterioration, loss of biodiversity, overexploitation of natural resources, and social inequality are some of the consequences derived from this separation between society and Nature. We must change our operating habits. Inevitably from a society based on the market, hyper consumption, fossil energy and individual enrichment at all costs, we will have to change to another
... Show More