Adsorptive removal of textile reactive dye using Posidonia oceanica (L.) fibrous biomass

The Mediterranean seagrass Posidonia oceanica (L.) leaf sheaths were used as low cost, available and renewable biological adsorbent for the removal of reactive textile dye from aqueous solutions. Batch experiments were carried out for sorption kinetics and isotherms. Operating variables studied were temperature, pH and chemical pretreatment. Biosorption capacity seems to be enhanced by increasing the temperature. Maximum colour removal was observed at pH 5. Pre-treating fibres with H3PO4 and HNO3 solutions increased the adsorption efficiency up to 80 %. Experimental sorption kinetic data were fitted to both Lagergren first-order and pseudo-second-order models and the data were found to follow first-order equation for raw fibres and pseudo-second-order for pre-treated ones. Equilibrium data were well represented by the Freundlich isotherm model for all tested adsorption systems. Besides, the thermodynamic study has showed that the dye adsorption phenomenon onto P. oceanica biomass was favourable, endothermic and spontaneous

Biosorption of metal dye from aqueous solution onto Agave americna (L.) fibres

In this research, a new low cost and abundant biosorbent; Agave americna (L.) fibres has been investigated in order to remove metal dye (Alpacide yellow) from aqueous solutions. In order to optimize the biosorption process, the effect of pH, temperature, contact time and initial solution concentration was investigated in batch system. The results indicated that acidic pH=2 was favourable for metal dye removal. The increase of temperature increases the velocity of the biosorption reaction. The biosorption kinetics of alpacide yellow were closer to the pseudo-second order than to the first order model for all concentrations and temperature. The calculated thermodynamic parameters such as ΔG0, ΔH0 and ΔS0 indicated a spontaneous and endothermic biosorption process of metal dye onto Agave americana fibres. The equilibrium data were analysed using the Langmuir and Freundlich isotherms and showed a good fit with Langmuir model at lower temperatures and with Freundlich model at 50 °C

Bio-Insecticidal Activity of Three Essential Oils against Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae)

Natural plant extracts, especially essential oils, are used largely against plant pests. The aim of this study was to investigate the bio-insecticidal effect of chemical extracts of three plants, Mentha pulegium L. (Lamiales: Lamiaceae), Lavandula stoechas L. (Lamiales: Lamiaceae) and Ruta chalepensis L. (Sapindales: Rutaceae) collected from Tunisia, on the lesser grain borer Rhyzopertha dominica (Fabricius, 1792) (Coleoptera: Bostrichidae), which is a primary pest of stored wheat. To reach this goal, we firstly did bio-assays to test the toxicity of these plant extracts on R. dominica adults using different concentrations of plant extracts on wheat seeds. Secondly, we analysed the chemical compounds of these plant extracts using GC-MS and GC-FID. Our results demonstrated that R. dominica mortality was significantly higher with increasing plant essential oils concentrations (CL95 values 45.68, 113.12 and 170.52 μl/l(air)) for M. pulegium, R. chalepensis and L. stoechas, respectively. The main chemical compounds identified of M. pulegium oils were: pulegone (76.9 %), isomenthone (12.0 %) and limonene (1.73 %), whereas those from L. stoechas were: camphor (23.8 %), 1,8-cineole (17.8 %) and camphene (7.69 %). Ruta chalepensis oil revealed high contents of undecanone (51.2 %), 2-nonanone (39.16 %) and 2-decanone (2.32 %). Our results also showed that M. pulegium essential oil has a significant effect against R. dominica with LC50 value of 13.51 μl/l(air) compared to R. chalepensis and L. stoechas corresponding to 39.11 and 42.9 μl/l(air), respectively

Poste de professeur-e en communication Tenure track position of Assistant Professor in Communication Studies

Le Département de communication sollicite des candidatures pour occuper un poste à temps plein de professeure ou de professeur de communication au rang d’adjoint (Université de Montréal)

Pilot-Scale Synthesis of Activated Carbons from Vetiver Roots and Sugar Cane Bagasse

International audienc

Flood Analysis Using HEC-RAS and HEC-HMS: A Case Study of Khazir River (Middle East—Northern Iraq)

Floods frequently threaten villages near the Khazir River’s floodplains, causing crop losses and threatening residential areas. We used flood-related hydrological software, including WMS and HEC-HMS, to study this issue and determine how to reduce the recurrence of flooding. The software can be used to calculate a hydrograph of torrential flows in a river drainage basin and estimate the volume of torrential water and its flow rates on the Earth’s surface. The depth of rain has been evaluated and calculated in the SCS Unit Hydrograph for different return periods of 2, 5, 10, 20, 50, and 100 years. According to our study’s findings, the volume of the river’s drainage basin floods ranged between 29,680 and 2,229,200 m3, and the maximum flow value ranged between 10.4 and 66.4 m3/sec during various reference periods. To analyze and model the flood risks of the Khazir River, the HEC-RAS model was combined with the HEC-GeoRAS extension in ArcGIS. The floods were the focus of two study periods, 2013 and 2018, and were based on the digital elevation model and river discharge during the floods. According to the classification map of the flood depths, the areas of flood risk varied from low to very low (80.31%), medium (16.03%), and high to very high (3.8%). The analysis of the results revealed that the villages closest to the river’s mouth were more affected by the floods than other villages further downstream. HEC-HMS and HEC-RAS have been shown to have a strong correlation in evaluating flood risks and reliably forecasting future floods in the study area

Mapping groundwater recharge potential zones in arid region using remote sensing and GIS perspective, Central Tunisia

Given the semi-arid to arid climate in the Regueb region of Central Tunisia, groundwater is a crucial resource for meeting the escalating demands of socioeconomic development. Careful estimation of the current recharge amount and the delineation of potential zones of rainfall precipitation are required for an accurate evaluation of the regional water balance in order to ensure sustainable development and preserve water resources. The aim of this study was to define the prospective locations for phreatic aquifer recharge by doing a preliminary assessment of the groundwater recharge in the Regueb basin. In order to determine the lateral variation of the recharge zone, ArcGIS was utilized in conjunction with a geological and hydrogeological database that was acquired. The obtained results indicated that there are five recharge potential areas: 5% of the study area has very low, 9% has low, 20% has moderate, 28.5% has good, and 36.5% (located principally in the southern part of the study region) has very good recharge potential. This distribution is controlled principally by the geomorphological, geologic, and hydrogeological features of the region. Reasonable management strategies based on the perennial exploitation of these low-renewable resources are required to optimize water-dependent socio-economic development. The environmental risk from groundwater and/or soil pollution and salinization (total dissolved solids (TDS) in groundwater ranged between 1.19 and 16.92 g/L) is undoubtedly explained by the dual actions of climatic conditions and mismanagement of land resources, especially in the agricultural sector, as the study area is mainly devoted to irrigation of vegetation. In addition, this study is helpful in the establishing and managing sustainable groudwater. An isotopic analysis is recommended to aid the decision maker in establishing an adequate strategy

Hydrogeological and water quality analysis of thermal springs in the Guelma region of North-Eastern Algeria: A study using hydrochemical, statistical, and isotopic approaches

This study aimed to investigate the hydrogeological features of aquifers in the Guelma Basin using hydrochemical, statistical, and isotopic analyses. The hydrochemical facies of phreatic waters were determined by analyzing 13 parameters of 14 water samples, and correlations between mineralization and contributing elements were identified through statistical analysis. Isotopic analysis was utilized to establish the groundwater's origin. The results showed that water in the Guelma Basin is generally hard, with varying levels of mineralization ranging from significant to excessive. Water quality worsens progressively as it flows in the direction of groundwater flow, particularly in the post-nappe domain due to water/rock interaction. Furthermore, the hydrochemical facies of phreatic waters differed based on their location, with calcium bicarbonates in the upstream and calcium chlorides in the downstream. Through statistical analysis, the study found that mineralization is positively correlated with elements contributing to mineralization, such as Na+ and Cl-. Electrical conductivity (CE) and Residual Salt (RS) were also positively correlated with these ions. Isotopic analysis revealed that the groundwater in the area has an old origin, and the & delta;2H and & delta;18O relationship identified mixing effects in the multi-aquifer system. Additionally, the upward movement of thermal water from deep to shallow aquifers is likely due to the abundance of fractures and faults in the research area. This study provides valuable insights into the hydrogeological characteristics of aquifers in the Guelma Basin and can inform future planning related to water, agriculture, or industry in the region. By using hydrochemical, statistical, and isotopic approaches, the researchers were able to determine the origin and movement of groundwater in the area, which can be useful for future decision-making. Overall, the study highlights the importance of understanding the hydrogeological characteristics of aquifers to make informed decisions regarding water management and resource utilization