Optimal conditions for olive mill wastewater treatment using ultrasound and advanced oxidation processes

© 2019 Elsevier B.V. The treatment of olive mill wastewater (OMW) in Jordan was investigated in this work using ultrasound oxidation (sonolysis) combined with other advanced oxidation processes such as ultraviolet radiation, hydrogen peroxide (H2O2) and titanium oxide (TiO2) catalyst. The efficiency of the combined oxidation process was evaluated based on the changes in the chemical oxygen demand (COD). The results showed that 59% COD removal was achieved within 90 min in the ultrasound /UV/TiO2 system. A more significant synergistic effect was observed on the COD removal efficiency when a combination of US/UV/TiO2 (sonophotocatalytic) processes was used at low ultrasound frequency. The results were then compared with the COD values obtained when each of these processes was used individually. The effects of different operating conditions such as, ultrasound power, initial COD concentration, the concentration of TiO2, frequency of ultrasound, and temperature on the OMW oxidation efficiency were studied and evaluated. The effect of adding a radical scavenger (sodium carbonate) on the OMW oxidation efficiency was investigated. The results showed that the sonophotocatalytic oxidation of OMW was affected by the initial COD, acoustic power, temperature and TiO2 concentration. The sonophotocatalytic oxidation of OMW increased with increasing the ultrasound power, temperature and H2O2 concentration. Sonolysis at frequency of 40 kHz combined with photocatalysis was not observed to have a significant effect on the OMW oxidation compared to sonication at frequency of 20 kHz. It was also found that the OMW oxidation was suppressed by the presence of the radical scavenger. The COD removal efficiency increased slightly with the increase of TiO2 concentration up to certain point due to the formation of oxidizing species. At ultrasound frequency of 20 kHz, considerable COD reduction of OMW was reported, indicating the effectiveness of the combined US/UV/TiO2 process for the OMW treatment

Efficient removal of phenol compounds from water environment using Ziziphus leaves adsorbent

© 2020 Elsevier B.V. Industrial processes generate toxic organic molecules that pollute environment water. Phenol and its derivative are classified among the major pollutant compounds found in water. They are naturally found in some industrial wastewater effluents. The removal of phenol compounds is therefore essential because they are responsible for severe organ damage if they exist above certain limits. In this study, ground Ziziphus leaves were utilized as adsorbents for phenolic compounds from synthetic wastewater samples. Several experiments were performed to study the effect of several conditions on the capacity of the Ziziphus leaves adsorbent, namely: the initial phenol concentration, the adsorbent concentration, temperature, pH value, and the presence of foreign salts (NaCl and KCl). The experimental results indicated that the adsorption process reached equilibrium in about 4 h. A drop in the amount of phenol removal, especially at higher initial concentration, was noticed upon increasing the temperature from 25 to 45 °C. This reflects the exothermic nature of the adsorption process. This was also confirmed by the calculated negative enthalpy of adsorption (−64.8 kJ/mol). A pH of 6 was found to be the optimum value at which the highest phenol removal occurred with around 15 mg/g at 25 °C for an initial concentration of 200 ppm. The presence of foreign salts has negatively affected the phenol adsorption process. The fitting of the experimental data, using different adsorption isotherms, indicated that the Harkins-Jura isotherm model was the best fit, evident by the high square of the correlation coefficient (R2) values greater than 0.96. The kinetic study revealed that the adsorption was represented by a pseudo-second-order reaction. The results of this study offer a basis to use Ziziphus leaves as promising adsorbents for efficient phenol removal from wastewater

Evaluation of the gulf of aqaba coastal water, Jordan

© 2020 by the authors. (1) Background: The Gulf of Aqaba (GoA) supports unique and diverse marine ecosystems. It is one of the highest anthropogenically impacted coasts in the Middle East region, where rapid human activities are likely to degrade these naturally diverse but stressed ecosystems. (2) Methods: Various water quality parameters were measured to assess the current status and conditions of GoA seawater including pH, total dissolved solids (TDS), total alkalinity (TA), Cl-, NO3-, SO42-, PO43-, NH4+, Ca2+, Mg2+, Na+, K+, Sr, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn. (3) Results: The pH values indicated basic coastal waters. The elevated levels of TDS with an average of about 42 g/L indicated highly saline conditions. Relatively low levels of inorganic nutrients were observed consistent with the prevalence of oligotrophic conditions in GoA seawater. The concentrations of Ca2+, Mg2+, Na+, K+, Sr, Cl-, and SO42- in surface layer varied spatially from about 423-487, 2246-2356, 9542-12,647, 513-713, 9.2-10.4, 22,173-25,992, and 317-407 mg/L, respectively. The average levels of Cd, Co, Cr, Cu, Fe, Mn, Pb and Zn ranged from 0.51, 0.38, 1.44, 1.29, 0.88, 0.38, and 6.05 μg/L, respectively. (4) Conclusions: The prevailing saline conditions of high temperatures, high evaporation rates, the water stratification and intense dust storms are major contributing factors to the observed seawater chemistry. The surface distribution of water quality variables showed spatial variations with no specific patterns, except for metal contents which exhibited southward increasing trends, closed to the industrial complex. The vast majority of these quality parameters showed relatively higher values compared to those of other regions

The Effect Of Controlling Hyperglycemia On The Morbidity And Mortality Of Intensive Care Unit (ICU) Patients

Introduction: Hyperglycemia and insulin resistance are common in critically ill patients, even if they have not previously had diabetes, and the risk of mortality or significant morbidity is high among those who are treated in the intensive care unit (ICU) for more than 5 days. Objective: To assess the effect of glucose management protocol on mortality and morbidity in a heterogeneous population of critically ill adult patients. Design: A randomized controlled trial. Setting: A 24-bed medical-surgical intensive care unit (ICU) for adult patients at King Hussein Medical Center, the Royal Medical Services. Methods: A total of 50 patients who were considered to need intensive care for at least three days, were randomly assigned into two groups. The intervention group subjects were to undergo a glucose control protocol with insulin infusion titrated to maintain blood glucose level in a target range of 120-160 mg/dL; except septic patients, in whom the target was higher, 160- 180 mg/dL. Patients in the second group (control group) were treated by a conventional approach with reduction of blood glucose level only if the level was markedly elevated (>200 mg/dL) to maintain blood glucose level in a target range of 180-200 mg/dL. Results: After adjustment for baseline characteristics the 2 groups of patients were well matched, for age, sex, prevalence of diabetes mellitus, HbA1c value and distribution of diagnoses; the only significant difference was in the percentage of cardiovascular dysfunction, which was higher in the intervention group (p=0.047). After institution of the protocol, the mean blood glucose levels differed significantly between the two treatment groups during the study period (143.70±12.78 mg/dL in the intervention group versus 175.56±14.07 mg/dL in the control group (p<0.001). And patients in the intervention group received a larger mean insulin dose 28.32 ±16.38 units per day, vs. 14.60±12.26 in the control group (p=0.001). The difference in mortality between the two treatment groups was not significant at 28 days (p=0.370) and at 60 days (p=0.555). No significant increase in hypoglycemia episodes was reported in our blood glucose level target. Conclusion: The glucose management protocol resulted in significantly improved glycemic control and was not associated with increased rate of death or hypoglycemia

Metal composition and contamination assessment of urban roadway dusts on the Abu Dhabi-Liwa Highway, UAE

The metal composition of road-deposited dust along the Abu Dhabi-Liwa Highway was investigated to provide insight into the contamination profile and levels of road dust. The average concentrations of metals decreased in the order Al (28668 ± 4631 mg/kg)\u3e Fe (21461 ± 2594 mg/kg) \u3e Mn (711.8 ± 76.3 mg/kg) \u3e Zn (210.6 ± 51.6 mg/kg) \u3e Cu (94.9 ± 15.8 mg/kg) \u3e Pb (83.6 ± 5.3 mg/kg) \u3e Cd (75.1 ± 1.6 mg/kg) \u3e Co (62.6 ± 6.4 mg/kg) \u3e As (4.7 ± 2.9 mg/kg) \u3e Ni (0.10 ± 0.19 mg/kg) \u3e Cr (0.08 ± 0.06 mg/kg). The spatial variations of metals suggest different sources and contributing factors for these metals, with most dust metals having mixed traffic and non-traffic origins. The contamination factor (CF) and enrichment factor (EF) showed identically the same order, Cd\u3e Pb\u3e As\u3e Zn\u3e Co\u3e Cu\u3e Mn\u3e Ni\u3e Cr, whereas the geoaccumulation index (Igeo) follows a slightly different ranking, Cd\u3e Pb\u3e Zn\u3e Co\u3e As\u3e Cu\u3e Mn\u3e Ni\u3e Cr. Based on EF and CF levels, roadway dusts are enriched in all metals, except for Ni and Cr. Similarly, the average Igeo values show differing rates of pollution for all metals except for Mn, Ni, and Cr. All pollution indicators suggest extreme pollution with Cd. The pollution loading index values showed sites 1–10 are generally polluted, while sampling sites from 11 to 19 are unpolluted with decreasing pollution loadings. Dusts collected from both sides of highway were higher in metal content than those obtained from the central reservation area. This may be due to the prevailing southeast wind direction, resuspension of road dust, and farmlands, among others. Soils bordering the highway showed high metal contents with potential consequences on the agricultural products

Safeguarding children in dentistry: 1. Child protection training, experience and practice of dental professionals with an interest in paediatric dentistry

* Few dental professionals with child protection training have experience of making referrals. * There is a wide gap in practice between recognising signs of child abuse and neglect and responding effectively. * This may indicate missed opportunities to save children from continuing abuse. * There is a need for improved child protection information, support and training for dental professionals. Abstract Following several highly publicised inquiries into the deaths of children from abuse and neglect, there has been much recent interest in the role and responsibility of all health professionals to protect children at risk of maltreatment. The findings of a postal questionnaire, sent in March 2005 to 789 dentists and dental care professionals with an interest in paediatric dentistry working in varied settings in the UK, are presented in a two-part report and discussed in the context of current multi-agency good practice in safeguarding and promoting the welfare of children. This first part explores reported child protection training, experience and practice. There was a significant gap between recognising signs of abuse and responding effectively: 67% of respondents had suspected abuse or neglect of a child patient at some time in their career but only 29% had ever made a child protection referral. The dental profession is alerted to the need to ensure necessary appropriate action to safeguard children is always taken when child abuse or neglect are suspected

Kinetic and thermodynamic study of phosphate removal from water by adsorption onto () reeds

The adsorption of phosphate ion onto natural reed ( Arundo donax ) was studied in this work. The effect of phosphate initial concentration, adsorbent dose, pH, temperature, and salt addition on adsorption uptake was investigated. The results showed that the adsorption uptake is directly proportional to the phosphate ion initial concentration and inversely proportional to the adsorbent's dose and temperature. A maximum adsorption capacity of 16.2 mg/g was observed at neutral pH. The addition of sodium and potassium chlorides has decreased the adsorption uptake. The adsorption isotherms agree better with the Langmuir model. The negative values of (ΔG) and (ΔH) obtained from the thermodynamic study, indicted that the adsorption process is spontaneous and exothermic. The experimental adsorption data were analyzed using three kinetic models: pseudo-first order, pseudo-second order, and intra-particle diffusion model. The pseudo-second-order model presented the best fit with a determination coefficient ( R 2 ) higher than 0.99 and a minimum normalized standard deviation

Investigation of Magnetic Properties of γ-Fe2O3 NP-Decorated Carbon Nanostructured Mats

Abstract It has been experimentally demonstrated that a carbon nanostructure (CNS)-based structure, called CNS mats, can yield superior magnetic properties. The structure is obtained by decorating CNS with γ-Fe2O3 nanoparticles (NPs) in a three-dimensional (3D) network structure. γ-Fe2O3 NPs are coated on the CNS, resulting in enhanced magnetic properties. The experimental characterization and theoretical analysis reveal that CNS mats decorated with γ-Fe2O3 NPs show superior magnetic properties compared with pristine CNS, as a result of the homogeneous dispersion of γ-Fe2O3 NPs and the highly aligned structure of the CNS. The coercive field (Hc), saturation magnetization (Ms), and remanent magnetization (Mr) were found to be 126 Oe, 22.3 emu/g, and 7.15 emu/g, respectively. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) characterization showed that the carbon nanotubes (CNTs) in each CNS flake within the CNS mat remained well aligned and formed an interconnected 3D network structure. This results in a robust porous structure with high electrical conductivity. Thermogravimetric analysis (TGA) revealed that the presence of the γ-Fe2O3 NPs provides a protective layer for the CNS and results in good thermal stability. The fabricated ultrathin CNS mat offers superior magnetic and electrical performance, making it an attractive candidate for microwave absorption, along with other applications such as electromagnetic shielding, sensors, lithium-ion batteries, and polymer composites

Models for using internet technology to support flexible e-learning

Information and Communication Technologies (ICTs) have been diffused in higher education slower than it has been expected. Especially for developing countries, using ICT in the most efficient and effective ways has crucial importance for the sustainable development and effective use of resources. This paper presents a theory-based design framework for e-learning that emphasises the transformative interaction between technology readiness and innovativeness. This study is a theory-building investigation and offers a theory-into-practice framework that characterises the implications of innovativeness and motivation in the recent trend of the higher education use of internet technology to facilitate its own operations, in the form of e-learning. Copyright © 2013 Inderscience Enterprises Ltd