The present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) process for water recovery from electroplating wastewater and study the factors affecting the performance of two membrane processes. Nanofiltration and reverse osmosis membranes are made from polyamide as spiral wound module. The inorganic materials ZnCl2, CuCl2.2H2O, NiCl2.6H2O and CrCl3.6H2O were used as feed solutions. The operating parameters studied were: operating time, feed concentrations for heavy metal ions, operating pressure, feed flow rate, feed temperature and feed pH. The experimental results showed, the permeate concentration increased and water flux decreased with increase in time from 0 to 70 min. The permeate concentrations increased and flux decreased with increase in feed concentrations from 10 to 300 mg/l. Raising of pressure from 1 to 4 bar, permeate concentration decreased for RO, for NF decreased and then increased at high pressure and increase the flux. The rises of flow rate from 20 to 50 l/h decreased permeate concentration and the flux increase. The rises of temperature from 26 to 40 °C, increased permeate concentration and increased the flux. The rise in pH from 4 to 7, decreased the flux as the pH goes from acidic side towards alkaline. The polyamide nanofiltration membrane had allowed permeation of chromium and copper ions to lower than permissible limits. Nanofiltration membrane had allowed permeation of nickel and zinc ions at low concentration of these ions. The polyamide RO membrane gave a high efficiency for removal of chromium, copper, nickel and zinc and it had allowed permeation of these ions to the lower than permissible limits. The rejection at first three minutes when the feed concentration approximately was constant for chromium in NF and RO, was 99.7% and 99.93%, for copper was 98.43% and 99.33%, for zinc was 97.96% and 99.49%, and for nickel was 97.18% and 99.49% respectively. The maximum recovery for chromium in NF and RO was 71.75% and 48.5%, for copper was 75.62% and 50.68%, for zinc was 80.87% and 54.56%, for nickel was 60.06% and 46.18% respectively. For a mixture of synthetic electroplating wastewater, nanofiltration and reverse osmosis membranes have a high rejection percentage for heavy metal ions. It was obtained pure water and concentrations of less than allowable limits for heavy metals in the case of the mixture.
The Prophet Muhammed () is distinguished in the history of mankind by the fact that he came with a law that combined these two opposing sides, reality and ideals, a wonderful and amazing collection, and he created a wonderful composition between them, and they used together a wise comprehension to ensure the treatment of its ills, and the reform of their delusions together, and uses both Both of them are in the necessary position of the needs of life, and the contradictions and separation of this collection and the wise harness in this research from his law, may God bless him and grant him peace, which shows us this balance in the system of Islam, the most sincere representation, where it is one of the honors of morality, good appreci
... Show MoreThe child realize that the meals time provide golden opportunities to get the attention the child needs. However, many difficulties that may appear about eating food can be avoided, if the family used the right way in dealing with this problem. The study aims, in this case, at searching for the reasons that lies behind the child's obstinacy in eating his food and the attempt to study some variables that is related to the research topic.
The results are summed up as follows:
- The number of the sample children is 3 of both sexes between the ages of 3 to 6 years
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Police play an important role in any society. Where they maintain public order by stopping and deterring crime and bringing criminals to justice. In order to achieve these objectives, they have certain means of law (search, arrest, use of force that may be lethal in some cases). However, such means may be misused in a way that harms members of society such as (Exceeding the Scope of a search warrant, violation of privacy of individuals, False Imprisonment, Excessive use of force, Sudden Deaths in custody, Sexual Assault and Harassment, Failure to respond for Domestic violence calls), which raises the civil liability of police officers and their agencies for such damage. Police officers may even abuse their characteristics even outside offic
... Show MoreBackground: Presence of maxillary sinus septa has been known to be a complicating factor for sinus elevation procedure and implant placement in posterior maxilla. The maxillary sinuses septa are thin walls of cortical bone inside the sinus. They vary in number, location, and height. This study aimed to discover the accuracy of Spiral Computed Tomographic Scan in evaluation the maxillary sinus septa (prevalence, location, height) in subjects with dentate, partially edentulous and completely edentulous maxilla. Material and method: This study included (267) subjects ranged from (20-70 years), (132) male and (135) female divided into three groups, (97) fully dentate group, (102) partially edentulous group and (68) completely edentulous group w
... Show MoreLaser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each.
... Show MoreBackground: The association between periodontal diseases incidence and development and the metabolic diseases as Diabetes Mellitus and Obesity are recently have attract great deal of researchers attention and investigation. The periodontal health proved to reduce the systemic inflammatory reactions and positively improve the glycemic control of diabetes Type2 patients. The aim of the study was to investigate the influence of oral hygiene control on the glycemic control of obese and normal weight moderately controlled Diabetic Type 2 patients, in addition to study the association of obesity with the gingival inflammation. Materials and Methods: Cross sectional study of three months duration. Included 30 moderately controlled diabetic type2 p
... Show MoreBackground: Generally, genetic disorders are a leading cause of spontaneous abortion, neonatal death, increased morbidity and mortality in children and adults as well. They a significant health care and psychosocial burden for the patient, the family, the healthcare system and the community as a whole. Chromosomal abnormalities occur much more frequently than is generally appreciated. It is estimated that approximately 1 of 200 newborn infants had some form of chromosomal abnormality. The figure is much higher in fetuses that do not survive to term. It is estimated that in 50% of first trimester abortions, the fetus has a chromosomal abnormality. Aim of the study: This study aims to shed some light on the results of chromosomal studies per
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The factorial analysis method consider a advanced statistical way concern in different ways like physical education field and the purpose to analyze the results that we want to test it or measure or for knowing the dimensions of some correlations between common variables that formed the phenomenon in less number of factors that effect on explanation , so we must depend use the self consistent that achieved for reaching that basic request. The goal of this search that depending on techntion of self consistent degree guessing for choosing perfect way from different methods for (orthogonal & oblique) kinds in physical education factor studies and we select some of references for ( master & doctoral) and also the scientific magazine and confere
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