This 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, alkane, alcohol, and alkyl halides groups are responsible for the bio-sorption of phenol onto GDAS.
A 2D advection-dispersion, solved numerically by computer solutions (COMSOL) Multiphysics 3.5a software which is based on the finite element method, has been used to simulate the equilibrium transport of phenol within groundwater. This model is taking into account the pollutant sorption onto the GDAS and sandy soil which is represented by Langmuir equation. Numerical and experimental results proved that the barrier plays a potential role in the restriction of the contaminant plume migration. Also, the barrier starts to saturate with contaminant as a function of the travel time. A good agreement between the predicted and experimental results was recognized with root mean squared error not exceeded the 0.055.
The crude enzyme Nattokinase produced by Bacillus subtilis was used in ripening cheddar cheese by adding three concentration of enzyme 80, 160 and 320mg/Kg beside the control treatment without enzyme, the product was checked for three months to determine humidity, protein, fat, non-protein nitrogen, soluble nitrogen and pH, sensory evaluation was conducted, it was noticed that the variety in protein percentages and the soluble nitrogen percentage during second month of ripening for T2, T3 and T4 treatments were (11.2, 15.54 and 18.48) respectively, in comparison with control which was 7.6%, while in the third month it was (17.37, 20.67 and 22.26) respectively, in comparison with control which was only 10%, on the other hand, non-protein
... Show MoreThe availability of low- cost adsorbent namely Al-Khriet ( a substance found in the legs of Typha Domingensis) as an agricultural waste material, for the removal of lead and cadmium from aqueous solution was investigated. In the batch tests experimental parameters were studied, including adsorbent dosage between (0.2-1) g, initial metal ions concentration between (50-200) ppm (single and binary) and contact time (1/2-6) h. The removal percentage of each ion onto Al-Khriet reached equilibrium in about 4 hours. The highest adsorption capacity was for lead (96%) while for cadmium it was (90%) with 50 ppm ions concentration, 1 g dosage of adsorbent and pH 5.5. Adsorption capacity in the binary mixture were reduce at about 8% for lead a
... Show MoreThe species of Cr (III), Cr (VI) in biological samples and V(IV), V(V) in foods & plants samples were determined by spectrophotometric methods. Integrated spectral studies of complexes [Cr (III, VI)-DPC], [Cr (VI)-bipy], [VO-SH], [V (V)-8-HQ] which included a study of the optimum conditions for the complexes formation by the investigation of the chemical and physical variables affecting each complex formation, the nature of complexes, the preparation of calibration curves of the complexes and treated the resulted data by modern statistical methods and study the interfering species. Interferences were removed to explain the reactions thermodynamically by determining Ecell, Keq. and ∆G values and includes a study of
... Show MoreBackground: Dentin removed during root canal system instrumentation for creating adequate geometry for the canal and cleaning the canal. A new instrument had been marketed with the aim of optimum shaping of all parts of the canal system, however, no information present about the amount of dentin removal compared to conventional rotary system. This study investigated the amount of dentin removal when the canal instrumented by SAF compared with ProTaper by using high resolution computed tomography (micro CT). Materials and Methods: Twenty extracted single canalled teeth were utilized for this study; and randomly divided into 2 groups. In the first group, the root canals were prepared by using protaper rotary system till F2 and the root canal
... 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%.
The purpose of this research was to evaluate rice husk functionalized with Mg-Fe-layered double hydroxide (RH-Mg/Fe-LDH) as an adsorbent for the removal of meropenem antibiotic (MA) from an aqueous solution. Several batch experiments were undertaken using various conditions. Based on the results, the optimal Mg/Fe-LDH adsorbent with a pH of 9 and an M2+/M3+ ratio of 0.5 was associated with the lowest particle size (specifically. 11.1 nm). The Langmuir and Freundlich models were consistent with the experimental isotherm data (R2 was 0.984 and 0.993, respectively), and MA’s highest equilibrium adsorption capacity was 43.3 mg/g. Additionally, the second-order model was consistent with the adsorption kinetic results.
Background: Pain and the usage of local anesthetic agents are still real problem in pediatric dentistry, for these reasons, the use of minimal invasive dentistry (MID) in regard to the patient comfort is important especially for children, anxious and uncooperative patients. Chemomechanical caries removal (CMCR) methods involve the selective removal of the carious dentine hence it avoided the painful removal of the sound dentine and the anxiety resulted due to the vibration of the hand piece which is also decreased thus it appears to be more acceptable and comfortable to the patient. Aims of this study: This study was conducted among group of children to assess and compare the anxiety rating scale (during and after treatment) between the
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