Search

Recent concerns about environmental pollution have highlighted the need for effective treatment of tannery effluents, which often carry high loads of malachite green oxalate (MGO), a harmful micro-pollutant in aquatic ecosystems. This study explores the use of argan nut shells (ANSs) as an adsorbent for MGO, aiming to develop an efficient method for mitigate its spread in water bodies. The adsorption process parameters were thoroughly examined to optimize ANS usage for maximum efficiency. Results showed that 0.08 g of ANS could effectively adsorb MGO and demonstrate that a small quantity of ANS, just 0.08 g, is capable of effectively adsorbing MGO, achieving a maximum adsorption capacity of 7.22 mg/g and the equilibrium time for the adsorption of MGO onto ANS was 40 min at both 35 °C and 45 °C and 50 min at 25 °C, indicating slight temperature dependence. The increase in temperature positively affected adsorption, confirming the endothermic nature of the process. Kinetic analysis revealed that the adsorption follows pseudo-second-order kinetics, with intraparticle diffusion not being the sole rate-controlling step. The adsorption behavior aligned with the Freundlich isotherm model, with significant adsorption occurring at pH 4–8. Thermodynamic parameters indicated a spontaneous (ΔG° < 0) and endothermic (ΔH° > 0) process, with a pHpzcvalue of 3.6. surface characterization using FTIR, XRD, SEM, and EDS confirmed the interactions between MGO and ANS, establishing confirming the efficacy of argan nut shells as a promising material for removing malachite green oxalate from aqueous solutions.

Despite its widespread use in many industrial applications, phenol is a hazardous pollutant that needs proper treatment before its discharge into the environment. Herein, a new activated carbon (AC) from Atlas oak wood was reported as adsorbent for phenol removal from aqueous solutions. The charcoal was activated with different acidic and basic solutions and characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption measurements to determine the structural and textural properties of the solids. The iodine number test and the pH at zero charge point were also determined and discussed. Its iodine number test and pH at zero charge point were also determined and discussed. Then, the phenol adsorption capacity of prepared activated carbons was evaluated under several operating conditions. The H3PO4-activated carbon had the highest adsorption capacity, which outperformed that of a commercially activated carbon. Optimum results were achieved at 2 h equilibrium time, a mass of adsorbent of 100 mg, and an initial concentration of 10−2mol/L at a pH = 4. The phenol elimination using acid-treated carbons gave extraction yields up to 98.77%, higher than that of the commercially activated carbon (91.48%) and base-treated carbons that showed unfavorable adsorption. An adsorbed quantity of the phenol of the order with a yield of 99% for the carbon was activated by H3PO4. The adsorption of phenol on activated carbon followed the second-order rate equation and Langmuir adsorption isotherm model. However, it should be noted that the adsorbed amount by activated carbon using H3PO4(Qm= 250 mg/g) exceeds that adsorbed by commercial carbon (Qm= 200 mg/g). Outcomes of this work can open a gate for the development of efficient natural-based adsorbents for the removal of pollutants from wastewater.

Agricultural wastes (AWs) are available abundantly at no or low costs; however, in most cases, not used reasonably. Despite their interesting chemical properties, coconut shells (CS), almond shells (AS), walnut shells (WS), and peanut shells (PS) are usually burned in the fields or discharged without any valorization. These AWs were investigated as low-cost bio-adsorbents to remove copper ions (Cu2+) from aqueous solutions. The four adsorbents were characterized using X-ray diffraction (XRD), the Fourier transform infrared spectra (FTIR), nitrogen adsorption/desorption measurements, scanning electron microscopy, and energy-dispersion X-ray spectroscopy (SEM–EDS). Characterization results revealed that the materials under investigation had porous surfaces, rich in fibers, and several potential adsorption sites. Therefore, their adsorption capacity for Cu2+removal was evaluated under different operating conditions. Results showed that the CS had the best adsorption capacity among tested AWs. Under optimized parameters, the highest adsorption capacity was found 25, 18, 10, and 5 mg/g for WS, CS, PS, and AS, respectively. The adsorption of Cu2+on the four adsorbents followed the second-order rate equation and the Langmuir adsorption isotherm model. After the adsorption process, the characterization of studied materials revealed no structural changes, proving the physical adsorption of Cu2+on shells through long-range interactions between Cu2+and reactive sites of adsorbents. The high adsorption capacity of the selected adsorbent was attributed to the presence of high content of cellulose compared to lignin.

Argania spinosais a well-known evergreen tree in Morocco and worldwide due to its significant ecological value, economic potential, and therapeutic uses. In this study, native and introduced Argan trees from two locations in Morocco (Oujda and Chouihiya) were compared for their chemical composition and in vitro antimicrobial activity. The sensitivity of different bacterial and fungal strains to Argan extracts was tested using the agar diffusion, agar well, and microdilution methods. The findings of the present study indicate that each extract from the different studied parts of the Argan tree contained a distinct amount of several compounds of considerable interest, including rutin, catechin, quercetin, and cinnamic acid, the major compound was Quercetin with a value of 18.12 mg/100g DW while the minor was trans Chalcon with a concentration of 0.01 mg/100G DW. The lowest MIC values and MBC value against bacterial strains were recorded by leaf extracts from Oujda against K. pneumoniaewith a value of 2.5 mg/mL. The lowest MIC observed for fungal strains was registered against Geotrichum spwith a value of 5 mg/ml. The outcomes from this work further support that Argan and its derivatives have a promising future in combating microbial problems.

The efficient utilization of biomass as a renewable energy source is critical for sustainable development and environmental conservation. This study aims to explore the influence of heating rate and fuel type on the kinetics and combustion behavior of peanut shell (PS) and sugarcane bagasse (SC), along with their respective solid biofuels, PS400and SC400. These biofuels were synthesized through pyrolysis at 400 °C for a duration of 2 h. Thermo-gravimetric analysis was employed to examine various combustion characteristics, including the combustion process, combustion index, and ignition index. Additionally, kinetic parameters for each sample were determined using the Coats-Redfern method. Our findings indicate that the raw biomass exhibits higher reactivity and a more significant combustibility index compared to the solid biofuels. Furthermore, these characteristics were observed to enhance with an increase in the heating rate. Regarding kinetic parameters, a decrease in activation energies was noted with an elevated heating rate for the biofuels. For the raw biomass, the activation energies diminished with an increased heating rate during the initial stage. However, during the second phase of the biomass analysis for both samples, the activation energies were found to escalate with the heating rate increment. These insights contribute significantly to the optimization of biomass utilization strategies, paving the way for more sustainable and efficient energy solutions.

By the example of 4-fluorobenzene-1-thiolate (p-FTP) films on Au(111), we show that a long-term post-preparation storage can improve significantly the quality of fluorinated aromatic self-assembled monolayers (SAMs). Whereas the freshly prepared p-FTP films exhibit a polymorphism, with a dominance of a disordered phase, the post-preparation storage triggers a gradual phase transition to a single-phase SAM of exceptional quality. This phase is characterized by the commensurate (16 × √3) structure, a molecular footprint of 23.1 Å2, high orientational order, and hardly perceptible borders between individual domains, with sizes exceeding 80 nm. Significantly, the phase transition is accompanied by morphological transformation of the substrate: whereas the freshly prepared films exhibit comparably large Au adatom islands, typical of aromatic SAMs, the long-storage samples rather reveal etch-pits, typical of alkanethiolate SAMs on Au(111), which generally have a high structural order immediately after the preparation. The above results suggest a deep interrelation between the structural order in the SAMs and surface morphology. A further implication is the importance of both thermodynamic and kinetic factors, a delicate interplay of which is presumably responsible for the observed evolution of p-FTP/Au in the present case.