Electrochemical and In Situ FTIR Study of o-Cresol on Platinum Electrode in Acid Medium

The electrochemical behaviour of o-cresol in acidic medium on platinum electrode has been studied by cyclic voltammetry and in situ Fourier transform infrared spectroscopy. The o-cresol suffers hydrolysis during oxidation giving rise to the formation of methyl-p-benzoquinone. In situ FTIR spectroscopic studies also reveal the presence of CO2, formed as a consequence of the rupture of the aromatic ring. Moreover, the oxidation of o-cresol in acidic medium produces a polymeric film on the platinum surface that precludes further oxidation of o-cresol. The reduction of o-cresol at potentials below 0 V produces in the first step the partial reduction of the aromatic ring and when the potential goes to values below 0 V, methyl-cyclohexanone.Ministerio de Economía y Competitividad and FEDER (MAT2010-15273) and Generalitat Valenciana (PROMETEO/2013/038) projects

Algerian natural montmorillonites for arsenic(III) removal in aqueous solution

The adsorption of As(III) from aqueous solutions using naturally occurring and modified Algerian montmorillonites has been investigated as a function of contact time, pH, and temperature. Kinetic studies reveal that uptake of As(III) ions is rapid within the first 3 h, and it slows down thereafter. Equilibrium studies show that As(III) shows the highest affinity toward acidic montmorillonite even at very low concentration of arsenic. The kinetics of As(III) adsorption on all montmorillonites used is well described by a pseudo-second-order chemical reaction model, which indicates that the adsorption process of these species is likely to be chemisorption. Adsorption isotherms of As(III) fitted the Langmuir and Freundlich isotherm models well. The adsorption of As(III) is pH-dependent obtaining an optimal adsorption at pH 5. From the thermodynamic parameters, it is concluded that the process is exothermic, spontaneous, and favorable. The results suggest that M1, M2, and acidic-M2 could be used as low-cost and effective filtering materials for removal of arsenic from water.This work has been financed by the Ministerio de Economía y Competitividad and FEDER (project MAT2010-15273). The National Agency for the Development of University Research (CRSTRA), the Directorate General of Scientific Research and Technological Development (DGRSDT) of Algeria

Catalytic degradation of O‐cresol using H2O2 onto Algerian Clay‐Na

Clay material is used as a catalyst to degrade an organic pollutant,. This study focused on the O‐cresol oxidative degradation in aqueous solution by adding H2O2 and Mont‐Na. The catalytic tests showed a high catalytic activity of Mont‐Na, which made it possible to achieve more than 84.6% conversion after 90 minutes of reaction time at 55 °C in 23.2 mM H2O2. The pH value was found to be negatively correlated with the degradation rate of O‐cresol. UV‐Vis spectrophotometry revealed that the increase of degradation rate at low pH is related to the formation of 2‐Methylbenzoquinone as intermediate product. In addition, the content of iron in Mont‐Na decreased after the catalytic test, bringing further evidence about the O‐cresol catalytic oxidation. The mineralization of O‐cresol is also confirmed by the different methods of characterization of Mont‐Na after the catalytic oxidation test. The effect of the O‐cresol oxidation catalyzed by natural clay is significant.Financial support for this work by the Algerian Directorate General of Scientific Research and Technological Development (DGRSDT) and the Ministry for Higher Education and Scientific Research is gratefully appreciated

Residue Analysis of Some PAHs in Some Algerian Soil: A Preliminary Environmental Impact Assessment

AbstractPolycyclic Aromatic Hydrocarbons are among the most persistent pollutants in various environmental matrices including soil. Because of their considerable toxicity even at low concentrations, it is essential to detect them at such very low levels (about ng/Kg) and to quantify them with precision and reliability. The objective of the present work is to determine residues of some PAHs in samples of superficial soil collected from a number of sites including the vicinity of an industrial park of a cement factory, rural soil, surrounding this industrial park, cereal grown soil close to the industrial park and also from urban ground in the north west of Algeria. A high resolution gas liquid chromatorgraph, coupled with high resolution mass spectroscopy (HRGC / HRMS) was used to measure PAH residues and their distribution in the soil. Results show that all investigated soil samples are highly contaminated with PAH. The concentration of the PAHs varies between 24, 62704.104 and 1072, 45064. 104 ng/kg. Residues of the potentially carcinogenic PAH benzo [a] pyrene, were also detected in some of the soil samples. Residues detected in the present study vary between 2,189.103 ng/kg and 506, 4848.103 whereas the value of Hazardous Substances Data Bank (HSDB) is approximately 2.103 ng/Kg. The present results indicated that soil samples examined in the present study are highly contaminated with PAHs compounds, posing potential toxicological risk, considering their carcinogenic and/or mutagenic properties

AGGEZI AND KORONEIKI OLIVE TREES AS AFFECTED BY ORGANIC AND BIO – FERTILIZERS, CALCIUM CITRATE AND POTASSEINE

The present study was carried out in an olive orchard at 6th of October city, Giza Governorate, Egypt during 2002 and 2003 growing seasons on “Aggezi” and “Koroneiki” olive cultivars for table and oil purposes, respectively. The objective of this study was to investigate the effect of organic farmyard manure (FYM), compost (COM) manure and biofertilizers (Bio) as the combination between phosphorene and nitrobeine, calcium citrate (Cac) and potasseine (K). Besides, the fertilization program adopted in the farm [N (750g/tree), P2O5 (600g/tree) & K2O (500g/tree)] was used as control. The results revealed that, the application of different aforemen-tioned treatments increased significantly shoot growth (length and diameter, number of leaves shoot and area/leaf) compared to the control in both cultivars (Aggezi and Koroneiki) during the two growing seasons. In this concern, the application of FYM+Cac influenced significantly shoot length & diameter, number of leaves/shoot and area/leaf of Koroneiki cv. and shoot diameter of Aggezi cv. Meantime the area /leaf of both cvs.increased when fertilized by FYM+COM+Cac. Whereas, the com-bination of FYM, COM, Cac, Bio, and K improved significantly blooming charac-teristics (number of flowers/inflorescence, inflorescence length and perfect flowers %) of Aggezi and Koroneiki olive cvs. However, number of fruits/shoot and yield of both cultivars increased significantly when treated by the combination of organic and biofertilizers, especially FYM+COM+Bio. Moreover, pulp/seed ratio was in-creased when treated with FYM+Bio (especially in 1st season). In addition, Koro-neiki cv. when provided with FYM+COM+Bio treatment produced the richest fruits in their oil content. Aggezi cv. trees when fertilized with the combination of organic manure & calcium, gave higher contents of chlorophyll (A), (B) & total chlorophyll, however, in Koroneiki cv. chlorophyll B didn't affect. Eventually, nutrient elements (NPK) contents didn't take a definite trend except for N which was affected signifi-cantly with the different combinations, while P & K in Aggezi leaves were influ-enced by FYM only. On the other hand, Koroneiki trees treated with COM+Bio had the highest leaf N content. Leaf P content was positively affected by FYM+Cac in 2002 and FYM+COM+Bio in 2003. Meantime, FYM+K followed by COM+Bio in-duced the highest stimulative effect on leaf K content

Kinetic and thermodynamic study of the adsorption of As(III) from aqueous solutions by naturally occurring and modified montmorillonites

[EN] Adsorption of As(III) from aqueous solutions using naturally occurring and modified Algerian montmorillonites was investigated as a function of contact time, pH and temperature. Kinetic studies reveal that uptake of As(III) ions is rapid within the first 3 hours and it slows down thereafter. Equilibrium studies show that As(III) shows the highest affinity towards Acidic-montmorillonite even at very low concentration of arsenic. A pseudo-second-order chemical reaction model was obtained for As(III). Adsorption isotherms of As(III) fitted the Langmuir and Freundlich isotherm models well. From the thermodynamic parameters, it is concluded that adsorption is exothermic, spontaneous and favorable. The results suggest that M1, M2 and Acidic-M2 could be used as effective filtering materials for removal of arsenic from water.This work has been financed by the AECID (projects AECID-PCI A/019533/08, A/023858/09 and C/031332/10) and Ministerio de Ciencia e Innovación (project MAT2010-15273). The National Agency for the Development of University Research (CRSTRA), the Directorate General of Scientific Research and Technological Development (DGRSDT) of Algeria.Zehhaf, A.; Benyouncef, A.; Quijada Tomás, C.; Taleb, S.; Morallón, E. (2012). Kinetic and thermodynamic study of the adsorption of As(III) from aqueous solutions by naturally occurring and modified montmorillonites. Biointerface Research in Applied Chemistry. 2(3):350-359. http://hdl.handle.net/10251/51537S3503592

Defying role of specific microorganisms on efficiency of organic materials (olive pomace) on the growth and productivity of olive trees

This study has been carried out through three successive seasons (2012, 2013 and 2014) on 12 years old Manzanillo olive trees in a private orchard located at 50 km of Cairo – Alexandria road in north-west of Egypt. The main objective of this study was to improve the physical and chemical properties of olive pomace by adding microorganisms specific to phenolic substances, which leads to their disposal and suitability for cultivation. Two microorganisms (Trichoderma virdi and Pseudomonas fluorescens) were evaluated to determine their promoting effect on the growth and productivity of olive trees. The experiment consisted of 9 treatments, 2 trees per treatment replicated 3 times in a randomized block design. Data exerted that, the treatment with compost 50 % + Pomace 50 % + Pseudomonas fluorescens gave the highest fruit set (%), yield, remaining fruits and leaf nitrogen and potassium. While, using the compost 75% + pomace 25 % + Trichoderma virdi + Pseudomonas fluorescens recorded the highest number of leaves and inflorescence/meter.Conclusively, it could be recommended under the same conditions of this study, using pomace (olive mill wastes) at the rate of compost (Comp.) 50 % + Pomce (Pom.) 50 % + Pseudomonas fluorescens (Pseu.) to increase the productivity of Manzanillo olive trees

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries