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THE THEORETICAL DESCRIPTION FOR THE ELECTROCHEMICAL PYROGALLOL AND HYDROXYQUINOL ELECTROCHEMICAL DETERMINATION OVER CoO(OH)-MODIFIED ELECTRODE
2024
Tkach, Volodymyr Valentynovych
The theoretical description for hydroxyquinol and pyrogallol electrochemical determination in food and wastewater has been made in this work. The efficiency of the cobalt (III) oxyhydroxide for this determination is verified from either electroanalytical and electrosynthetical point of view, as it also provides the assisted electro(co)polymerization. The stable steady-state is easy to obtain and maintain, which confirms the efficiency of the electrode modifier and the easy interpretation of analytical signal.
Mostrar más [+] Menos [-]THE THEORETICAL ASPECTS OF THE ELECTROSYNTHESIS AND ELECTROPOLYMERIZATION OF SOME NAPHTHOQUINONIC DERIVATIVES IN NEUTRAL AND ACIDIC MEDIA
2024
Tkach, Volodymyr Valentynovych
For the first time, the possibility of the electrochemical synthesis and polymerization of some novel modified naphthoquinonic compounds has been described. The correspondent mathematical model has been analyzed by means of linear stability theory and bifurcation analysis. It has been shown that the electroorganic synthesis may serve as an interesting substitution for Suzuki reaction for the synthesis of ferrocenyl naphthoquinone and its polymer. The oscillatory and monotonic instability in this case will be more probable than in the general electropolymerization case.
Mostrar más [+] Menos [-]Study of the effect of the weather factors on the mechanical properties of the composite material of foam polystyrene and natural wool: Study of the effect of the weather factors on the mechanical properties of the composite material of foam polystyrene and natural wool
2024
montajb
This study investigates the utilization of natural wool as a natural additive to foam styrene, aiming to assess its influence on the mechanical properties of the resulting composite material. Previous research on wool processing was utilized before adding it, our research concluded that 15% wool treaded wool yielded the best rate in terms of water absorption and combustion time. However, it was observed that compression resistance increased with higher additive ratios. The effect of weather factors on the resulting material was investigated by subjecting it to external atmospheric conditions for four months. Repeated tests were conducted to distinguish any variations in the properties of the composite material before and after exposure to these weather factors
Mostrar más [+] Menos [-]Microfiltration ceramic membranes from Cameroonian in Allophane rich soils and husked rice: physico-mechanical, chemical characterization and application to the treatment of drinking water
2024
paul nestor, djomou djonga
The presence of particles in drinking water and their resistance to several disposal methods is a major problem in Cameroon. The work presented in this manuscript focused on the synthesis of a ceramic membrane based on allophane rich soils for effective microfiltration in the clarification of drinking water. This work focused on the assessment of the suitability of allophane rich soils and rice hulls for the domestic treatment of drinking water. Rice hulls from the city of Yagoua have been used as a blowing agent. Several formulations have been produced with different allophane and husk rice proportions (60-40, 70-30, 80-20 and 90-10%) and at a sintering temperature of 1200 °C. The originality of this membrane lies in its monolayer structure which is at the same time the support layer and the active layer for microfiltration. The filters were characterized, the filtration tests were carried out. Chemical analysis of the raw materials revealed a high level of essential minerals. The thermal analysis made it possible to stop the heat treatment at 1200°C. Textural analysis of the membranes revealed that the formulated membranes had pore volumes between 30 and 43%. These characteristics are consistent with microfiltration. SEM carried out on the surface and in cross section of the membranes revealed that the pores are uniformly distributed over the entire surface and interconnected in depth. The membranes have been subjected to good mechanical and chemical resistance. These membranes can therefore be used effectively for microfiltration assisted by transmembrane pressure. We obtain a minimum flow rate of 17.43 mL/hour and a final turbidity of 7.65 NTU. This value is close to the quality limits of drinking water according to the standard of the French government which fixes the turbidity of tap water less than or equal to 2 NTU while UNICEF fixes this standard at 5 NTU.
Mostrar más [+] Menos [-]EFFECTIVENESS OF CHITOSAN AND NANO–CHITOSAN FOR PHENOL REMOVAL FROM REFINERY EFFLUENT
2024
Ibrahim, Abubakar Abubakar | Abdulfatai , Jimoh
Water is fundamental to all living creatures but unfortunately, it is the most poorly managed resource on the earth.Refinery discharges are parts of ways water sources are contaminated and prominent water contaminants include phenol which are more often discharged without treatment.Phenol is considered to be a very toxic pollutant in refinery wastewater which poses danger to man and its environment. In the present study, the goal was to establish the effectiveness of phenol removal using chitosan and nano – chitosan obtained from crab shells. The experiments were conducted at various conditions for both chitosan, nano – chitosan to achieve basic polysaccharide of low molecular weight chitosan (LMWC) and low molecular weight nano – chitosan (LMWNC) for removal of phenol from the refinery wastewater. Various techniques were used to characterize both chitosan, nano -chitosan and refinery wastewater, such as Double beam UV- spectrophotometer, Fourier Transforms Infrared Spectroscopy (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Dynamic Light Scattering (DLS), Shaking Water Bath and Viscometer.The characterization of obtained chitosan and nano-chitosan absorbents showed good surface area, high pore sizes, effective size reduction yield of over 80 %, effective demineralization with good content of macro elements and good molecular weight and viscosity relationships. The values of calcium were 6.6972, 5.6422 for CTS and NCTS respectively. The results of interaction revealed at factors of 35 % sodium hydroxide, 3 h and 75 oC gives the degree of deacetylation (DD) to be 81.75 %. Phenol removal was compared with both chitosan and nano – chitosan respectively. The modified chitosan known as nano – chitosan enhancesthe adsorption capacity due to higher surface areas.
Mostrar más [+] Menos [-]Determination of Pesticide Residues in cocoyam (Colocasia esculenta) from Selected Local Government Areas of Plateau State, Nigeria
2024
Kutshak, Panpe Iliya | Tukura, Bitrus W | Madu, Pascal Chima
This study was conducted to determine the level of pesticide residues in cocoyam (Colocasiaesculenta) from Mangu, Bokkos and BarkinLadi Local Government Areas of Plateau State, Nigeria.Cocoyam and soil samples were collected from two (2) farms each, from the study areas and analyzed for pesticides residues by gas chromatography equipped with electron capture detector.Fourteen (14) different pesticide residues were detected; HCB, p,p’-DDE, Endosulfans, p,p’-DDD, Glyphosphate, Dichlorvos, aldrin, Emamectin, Lindane, t-Nonachlor, 4,4-bypyridinium, Isopropylamine, g-chlordane, heptachlor. The concentrations of pesticide residues are in the range 0.0003-0.3579 mg/kg in cocoyam and 0.0001-1.1377 mg/kg in soil. Cocoyam samples, HCB (0.3579 mg/kg) had the highest concentration while t-nonachlor (0.0003 mg/kg) had the lowest concentration. In the soil samples analyzed, HCB (1.1377 mg/kg) was detected with the highest level while glyphosphate (0.0001 mg/kg) was found to have the lowest level. Cocoyam was found to contained the highest level of residues with HCB (0.3579 mg/kg) in BarkinLadi. Endosulfan, Lindane, t-nonachlor, Aldrin, glyphosphate and g-chlordane showed concentrations below the EU maximum residue limit (MRL), while HCB, p,p’-DDE, p,p’-DDD, Dichlorvos, Emamectin, 4,4-bypyridinium, Isopropylamine, and heptachlor showed concentrations above the EU maximum residue limit (MLR).The continuous consumption of such foods with high pesticide levels can accumulate and could result in detrimental chronic effects in the health of consumers. The statistical analysis showed that there is no significant difference between the individual concentrations and the concentrations at the different sample locations at P≤0.05.
Mostrar más [+] Menos [-]A CORROSION INHIBITION OF MILD STEEL IN HCL MEDIA USING GREEN INHIBITORS: A REVIEW: CORROSION INHIBITION OF MILD STEEL IN HCL MEDIA USING GREEN INHIBITORS: A REVIEW
2024
IORHUNA, Fater | Ayuba, Abdullahi Muhammad | Nyijime, Thomas Aondofa
Using corrosion inhibitors is a reasonably priced way to reduce corrosion in mild steel. Inhibitors that are affordable, biodegradable, and environmentally benign are being created and put to use. Various characterization techniques and electrochemical approaches have been applied in numerous studies to evaluate plant-based extracts. Although plant extracts appear to be a good alternative to commercially manufactured inhibitor formulations, extensive tuning is required. The majority of plant extract research investigations do not explain other synergistic combinations found in commercial inhibitor formulations. Consequently, it would be ideal to continue studying plant extracts as corrosion inhibitors while making use of the most recent developments in technology, such as optimization through quantum and molecular simulation and an emphasis on producing outcomes with fewer errors.
Mostrar más [+] Menos [-]Carbon-Based Adsorbent for Remediation of Per-And Polyfluoroalkyl Substances from Industrial Wastewater
2024
Samuel, Humphrey | Okibe, Gideon | Undie, David | Ochepo, Esther
Per- and polyfluoroalkyl substances (PFAS) have emerged as a significant environmental concern due to their persistence, bioaccumulative nature, and adverse health effects. Industrial wastewater streams often contain elevated levels of PFAS, posing a threat to aquatic ecosystems and human health. Conventional wastewater treatment methods are often ineffective in removing PFAS, necessitating the development of alternative remediation strategies. Carbon-based adsorbents have shown promise as efficient and cost-effective materials for PFAS removal from wastewater due to their high surface area, tunable surface chemistry, and strong adsorption affinity towards PFAS compounds. This study explores the recent advancements in the utilization of carbon-based adsorbents for the remediation of PFAS from industrial wastewater. Various types of carbonaceous materials, including activated carbon, carbon nanotubes, graphene-based materials, and biochar, have been investigated for their efficacy in PFAS adsorption. Carbon-based adsorbents offer a promising solution for the remediation of PFAS-contaminated industrial wastewater, with the potential to mitigate environmental pollution and safeguard human health.
Mostrar más [+] Menos [-]The Effect of PAC and Alum Coagulants on the Reduction of Organic Matter in River Water during the Coagulation-Flocculation Process (Case Study: 12 Main Rivers during Dry and Rainy Seasons in West Java Province, Indonesia)
2024
lolo, elvis umbu
Natural organic matter (NOM) present in rivers affects the coagulation process in drinking water treatment, specifically coagulation and flocculation processes. Therefore, it is necessary to conduct a laboratory-scale research using jar test. Natural organic matter (NOM) is found in most surface waters in West Java Province, along with suspended particles, colloids, and pathogens. The Jar test apparatus is a laboratory-scale coagulation-flocculation process used to determine the optimal coagulant dosage. Research results indicate that both PAC and alum coagulants affect the coagulation-flocculation process, with PAC exhibits more efficient effect. This advantage can be seen in the floc settling velocity, where PAC flocs settle by 0.80 cm/minute during the rainy season and 0.94 cm/minute during the dry season, while alum coagulant settle by 0.29 cm/minute for both rainy and dry seasons. Another advantage can be observed in the efficiency of NOM reduction. During the rainy season, the NOM reduction efficiency of PAC was 82%, and during the dry season, it was 77%, while alum coagulant reduction efficiency was 74% during the rainy season and 72% during the dry season. The coagulant's response to NOM reduction can also be noticed from the coefficient of determination. The coefficient of determination for PAC coagulant during the rainy and dry seasons were 45.79% and 20.58%, respectively, while alum coagulant values were 32.99% and 19.71% during the rainy and dry seasons, respectively.
Mostrar más [+] Menos [-]Machine Learning in Chemical Kinetics: Predictions, Mechanistic Analysis, and Reaction Optimization.
2024
Samuel, H.S. | Etim, Emmanuel E. | Nweke-Maraizu, Ugo | Yakubu, Shedrach
Chemical kinetics is a core area of physical chemistry that examines the speeds of chemical processes and the mechanisms that underlie them. Machine learning (ML) techniques have become effective tools for improving understanding and prediction in this area. The use of machine learning in chemical kinetics research is examined in this abstract, with particular emphasis on how it can be used to forecast A deeper knowledge of reaction kinetics is made possible by the capability of machine learning (ML) to handle high-dimensional data and learn from many chemical systems. This opens up significant opportunities for developing new chemical processes, improving catalysis, and hastening the discovery of new materials.
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