Ndi Julius Nsami

Green Chemistry Preparation of Canarium Schweinfurthii Activated Carbon/Silver Nanoparticle Composite as Effective Antibacterial Agent for Bacterial Polluted Water Treatment

Gadjui Youatou Boris, Ankoro Naphtali Odogu, Kouotou Daouda, Lunga Paul Keilah, Ndi Julius Nsami, Ngomo Horace Manga et 1 autre(s)

European journal of applied sciences

Targeting contaminated water containing dye and bacteria is primordial to humans. The adsorption technique has been efficient, but an added antibacterial proper is prime to modern-day functioning. Silver nanoparticles provide an excellent platform for biological and material applications due to their unique physical and chemical properties. Three potential materials were prepared namely Canarium schweinfurthii activated carbon (CSAC), Silver nanoparticles (AgNP) and Canarium schweinfurthii activated carbon/Silver nanoparticles (CSAC/AgNP). Canarium schweinfurthii (CS) precursors were subjected to thermogravimetric analysis (TGA), CSAC material was characterized by scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray fluorescence (XRF), Fourier transformed infrared spectroscopy (FT-IR) and nitrogen adsorption/desorption (N2-BET) and the AgNP was investigated using UV-Visible analysis. The UV-visible analysis of the nanoparticle shows a strong surface Plasmon resonance peak at 471 nm; the CSAC sample presented high methyl orange (MO) dye uptake varying from 48.293 to 98.328 mg/g. CSAC sample and the extract gave no antimicrobial properties while AgNP and CSAC/AgNP samples exhibited strong antibacterial activities while AgNP had a bactericidal effect on the six bacteria isolates of EC ATCC25922: Escherichia coli ATCC25922; SA ATCC43300: Staphylococcus aureus ATCC 43300; SANR 46003: Staphylococcus aureus NR 46003; S.cho NR-170: Salmonella choleriesus NR-170; SENR 13555: Salmonella enteritica 13555; SENR 4811: Salmonella enteritica 4811.

• #adsorption and biosorption for pollutant removal
• #nanoparticles: synthesis and applications
• #carbon and quantum dots applications
• #nanoparticle

Author response for "Magnetic core-satellite Fe/Cu@Zeolite 13X nanocomposite as an efficient catalyst: Performance in indigo carmine and tetracycline degradation"

Frank Dorinel Solefack Feudjio, Christian Brice Dantio, Georges Kenda Teikam, Donald Raoul Tchuifon Tchuifon, Roussin Lontio Fomekong, Rahman Abdoul Ntieche et 3 autre(s)

• #indigo carmine
• #nanocomposite
• #tetracycline
• #indigo

Evaluation of Phenobarbital Adsorption Efficiency on Biosorbents or Activated Carbon Obtained from Adansonia Digitata Shells

Charnella Stevine Dibandjo Ndankou, Daniela Simina Ștefan, Ndi Julius Nsami, Kouotou Daouda, Magdalena Boșomoiu

Materials

The removal of pharmaceutically active compounds present in relatively low concentration in wastewater is critical. This is because they have a severe, negative impact on life and the environment. To address this issue, adsorption was used, which is an effective wastewater treatment method for removing substances found in low concentrations in water. This study compared the adsorption performance of active carbon to three biosorbents derived from Adansonia digitata shells. The adsorbents were prepared and characterized using TGA, SEM, EDX, and FTIR analyses and pHPZC. To better understand the adsorption process, equilibrium and reaction kinetics studies were conducted. The effect of contact time, initial phenobarbital concentration, adsorbent mass, and pH was investigated in static conditions. The adsorption results revealed that the biosorbent B3 has a higher affinity for the eliminated compound, with an equilibrium time of 60 min and an adsorption capacity of 47.08 mg/g at an initial concentration of 50 mg/L. The experimental data are consistent with Langmuir and Sips adsorption isotherm models, and with the pseudo-second order and Elovich models for kinetics description. This indicates strong interactions between the adsorbent materials and the pharmaceutical micropollutant. Based on these findings, it appears that, among the tested materials, B3 biosorbent is the most efficient for removing phenobarbital present in low concentrations in water.

• #adsorption and biosorption for pollutant removal
• #adsorption
• #activated carbon
• #chemistry

CI Acid Orange 52 Dye Removal Using Natural and Formulated Clay-Lime Materials: Isotherm, Kinetic and Thermodynamic Studies

Fumba Gaston, Essomba Jean Serge, Ankoro Naphtali Odogu, Kouotou Daouda, Bélibi Bélibi Placide Désiré, Ndi Julius Nsami et 1 autre(s)

Journal of Materials Science and Chemical Engineering

The main objective of the study is to improve the removal efficiency of Ourlago-kaolin (Kao), sodium montmorillonite (Na-MMT), and two formulated clay-lime (F13 and F23) towards CI Acid Orange 52 dye (AO52). F13 and F23 were obtained by chemical stabilization through thermal treatment at 300°C. Fourier Transform Infrared spectra showed different surface functional groups on the clay materials, X-ray diffraction patterns revealed the raw materials contain many crystalline phases, scanning electron microscopy micrographs showed the variation of the layered structures of different clay materials, energy dispersive X-Ray analysis micrographs revealed compositional information and thermogravimetric-differential scanning calorimetry curves indicated the higher weight loss of 11.26% and 11.38% were observed for F13 and F23 respectively. BET surface area analyzed gave 133.0071 m2•g−1 for F13 and 132.34803 m2•g−1 for F23. The optimum pH value was 2.0 for Kao and Na-MMT. The adsorption experiments indicated that F13 and F23 have the maximum uptake abilities of 7.8740 and 3.1645 mg•g−1, respectively, compared to Kao (0.8761 mg•g−1) and Na-MMT (2.6178 mg•g−1). The pseudo-second-order model well described the adsorption kinetic model of AO52 dye onto the overall samples; Langmuir and Freundlich’s isotherms appropriately described the uptake mechanism. The positive values of ∆G° and negative value ∆H° indicated that the adsorption process was spontaneous and endothermic for Na-MMT, and non-spontaneous and exothermic for Kao, F13, and F23 because of their positive values of ∆G° and negative value of ∆H°. The modified clays have higher adsorption capacities and better life cycles compared hence opening new avenues for efficient wastewater treatment.

• #adsorption and biosorption for pollutant removal
• #nanomaterials for catalytic reactions
• #clay minerals and soil interactions
• #montmorillonite

Effect of Biogenic Silica Behavior in the Incorporation of Mesoporous Anatase TiO2 for Excellent Photocatalytic Mineralization of Sodium Diclofenac

Christian Brice Dantio Nguela, Ngomo Horace Manga, Clément Marchal, Aimé Victoire Abega, Ndi Julius Nsami, Didier Robert

Catalysts

TiO2/SiO2 composites were synthesized via a simple sol gel method by surface reduction of Ti4+ ions to Ti3+ using titanium isopropoxide as a TiO2 precursor and rice husks (RHA) as a SiO2 source. The silica content and calcination temperature of the materials were evaluated. Thermal, crystallographic and physicochemical aspects suggest that biogenic silica (SiO2) can improve the thermal stability of the anatase phase of TiO2, when the SiO2 content reaches 20%. The N2 adsorption-desorption isotherms showed that the SiO2-modified samples have uniform pore diameters and a large specific surface area. The XPS analysis showed the surface reduction of Ti4+ ions to Ti3+ within the TiO2 network via oxygen vacancies after SiO2 introduction, which is beneficial for the photocatalytic reaction. Photocatalytic degradation of sodium diclofenac (SDFC) shows that TiO2/SiO2 composites have better activity compared to commercial P25. Mesoporous TiO2 composite modified with 20 wt% SiO2 showed better photocatalytic mineralization than P25 (83.7% after 2 h instead of 57.3% for P25). The excellent photocatalytic mineralization of the photocatalysts can be attributed to the high anatase crystallinity exhibited by XRD analysis, high specific surface area, surface hydroxyl groups, and the creation of oxygen vacancy, as well as the presence of Ti3+ ions.

• #advanced photocatalysis techniques
• #tio2 photocatalysis and solar cells
• #advanced nanomaterials in catalysis
• #photocatalysis

Activated Carbon from the Peelings of Cassava Tubers (Manihot esculenta) for the Removal of Nickel(II) Ions from Aqueous Solution

Brice Armel Ajouafeu Alongamo, Lydie Dodo Ajifack, Julius Numbonui Ghogomu, Ndi Julius Nsami, Joseph Mbadcam Ketcha

Journal of Chemistry

Activated carbons were obtained from the peelings of cassava tubers (Manihot esculenta) by chemical activation using potassium hydroxide and phosphoric acid at impregnation ratios of 2 : 1 and 1 : 1, respectively, at 400°C for batch adsorption of nickel(II) ions from aqueous solution. Characterization of activated carbon samples was achieved via proximate analysis, Fourier-transform infrared spectroscopy, pH of zero-point charge, Boehm method, elemental analysis, scanning electron microscopy, and iodine number determination for each adsorbent. The effects of pH, contact time, initial adsorbate concentration, and adsorbent dose were studied at 27°C in order to optimize the conditions for maximum adsorption. Equilibrium was attained after 40 minutes of contact of both materials with activating solutions. Maximum adsorption capacities of 41.15 mg/g for ACPH, 47.39 mg/g for ACPA, 35.34 mg/g for NIC, and 34.48 mg/g for RM, respectively, were obtained at pH = 4. Equilibrium data showed that the Langmuir model best described the adsorption process with R2 closed to unity, indicative of monolayer adsorption on a homogeneous surface. Kinetic studies showed that the adsorption process is controlled by the pseudo-second-order model. These results show that activated carbon prepared from cassava peelings constitutes an effective low-cost material for the treatment of wastewater containing nickel(II) ions.

• #adsorption and biosorption for pollutant removal
• #chemistry
• #adsorption
• #activated carbon

Effect of doping activated carbon based Ricinodendron Heudelotti shells with AgNPs on the adsorption of indigo carmine and its antibacterial properties

Ankoro Naphtali Odogu, Kouotou Daouda, Lunga Paul Keilah, Godwin Agbor Tabi, Lekene Ngouateu Rene, Ndi Julius Nsami et 1 autre(s)

Arabian Journal of Chemistry

Two adsorbents samples namely ZnCl2 Activated carbon (ACZ); and a composite from ACZ doped with silver nanoparticles (ACZ/AgNP) made by successful precipitation loading onto ACZ and silver nanoparticles of the Recinodendron heudelotti shells aqueouse extract (RHSNP) were prepared. The ACZ and ACZ/AgNP materials were characterised by scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray diffraction (XRD) and particle size by Zeta sizer. The antibacterial activities of ACZ, ACZ/AgNP the RHSNP and the RHS extract was done by the broth microdilution test on Shigella flexneri, Salmonella typhi and Escherichia coli species. Futhermore, the adsorption capacities of the ACZ and the ACZ/AgNP was investigated using the hazardous Indigo Carmine (IC) dye. The SEM results shows spongy rock-like surface on both adsorbents (ACZ and ACZ/AgNP) with the presence of pores, EDX and XRD shows the presence of crystalline zincite on ACZ and Ag on the ACZ/AgNP. The FTIR spectral for both adsorbents preseumes a composite material while the zeta sizer shows that all the materials samples prepared were in the nano-range. The extract and ACZ showed no antimicrobial activities while the antimicrobial properties were proven to be very interesting for the nanoparticles and the ACZ/AgNP but higher for the ACZ/AgNP (7.812 ≤ MIC ≤ 31.25 µg/ml). The adsorption capacities of IC were found to decrease by 33.15% respectively using the maximum concentration at equilibrium. RHS is therefore a good and promising precursor for the preparation of activated carbon and nanoparticles for bacterial containing water purification and for the treatment of bacterial infections.

• #nanoparticles: synthesis and applications
• #carbon nanotubes in composites
• #graphene and nanomaterials applications
• #indigo carmine

An ef fi cient heterogeneous Fenton catalyst based on modified iron rich soil for discoloration of Tartrazine simulated wastewater

Tagne Guy Merlain, Daouda Kouatou, Ndi Julius Nsami, Sobdo Tsoupa Michel Crepin, Essomba Jean Serge, Lawrence Tatanah Nanganoa et 1 autre(s)

DOAJ (DOAJ: Directory of Open Access Journals)

An iron rich soil resource containing 67% Fe2O3 that is inactive towards the discoloration of tartrazine (TA) at neutral pH was used to prepare composites with charcoal obtained from aniline. The Composites were obtained by heating this soil, aniline and sulphuric acid under air at 400°C and 600°C and the products (or catalyst) were denoted as Cal400 and Cal600, respectively. Cal400 and Cal600 were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X‐ray Diffraction, X‐ray Fluorescence and Nitrogen adsorption Brunauer‐Emmet‐Teller (N2‐BET). Their catalytic activities were monitored by discoloration of tartrazine yellow dye and were performed by varying catalyst load (0.065, 0.125, 0.250, 0.375 and 0.500 g/L), H2O2 concentration (8, 16, 24 mol/L) and pH (5, 7, 8).The influence of NaCl, Na2CO3 and NaHCO3 (1g/L) on the catalytic performance and the influence of initial pH on the iron leaching was also addressed. 94% of tartrazine was discolored after 120 min of reaction with catalyst dose of 0.065 g/L; initial tartrazine concentration of 55 mg/L; H2O2 concentration of 8mM and initial pH = 7. Leaching test indicated that the leached iron from the catalyst was less than 5 mg/L. Although all ions under study inhibited discoloration significantly, the inhibition efficiency of Cl‐ is less than that of the others ions.

• #dye analysis and toxicity
• #molecular sensors and ion detection
• #electrochemical analysis and applications
• #tartrazine

Antibacterial properties of AgNO3-activated carbon composite on Escherichia coli: inhibition action

Nkwaju Yanou Rachel, Baçaoui Abdelaziz, Ndi Julius Nsami, Kouotou Daouda, Abdelrani Yaacoubi, Lourrat Mehdi et 2 autre(s)

International Journal of Advanced Chemistry

AgNO3- activated carbon composite based palm kernel shell was prepared by hydrothermal carbonization. The concentration of AgNO3, activation temperature and impregnation time were investigated on five responses (iodine number, methylene blue number, BET surface area, micropore volume and total pore volume). The most influential parameters of the preparation process were optimized using the Doehlert optimal design. From the ANOVA, the following optimal conditions of preparation were retained: 0.068 mol/L, 210°C and 3.7 h for AgNO3 concentration, activation temperature and impregnation time respectively. The activated carbon (AC) and the composite (AC-AgNO3) were characterized using Fourier Transform infrared spectroscopy, X-Ray diffraction, Scanning Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy and measurements of the surface area. The XRD pattern and SEM-EDX clearly confirmed the presence of silver in the composite. The experimental parameters of AC- AgNO3 composite were as followed: 708.44 mg/g; 293.09 mg/g; 713.0 m2/g; 0.49 cm3/g and 0.76 cm3/g, for iodine number, methylene blue number, BET surface area, micropore volume and total pore volume of AC- AgNO3 respectively. The antibacterial test carried on Escherichia Coli showed that AC-AgNO3 composite has a high-improved antibacterial property of 99.99% fixation with a dosage of 1500 ppm for 5 hours of contact time.

• #graphene and nanomaterials applications
• #medicinal plants and neuroprotection
• #natural products and applications
• #nuclear chemistry

Adsorption Study of the Removal of Copper (II) Ions using Activated Carbon Based Canarium Schweinfurthii Shells Impregnated with ZnCl2

Kammegne Adelaide Maguie, Ndi Julius Nsami, Kouotou Daouda, Che Nangah Randy, Ketcha Joseph Mbadcam

IRA-International Journal of Applied Sciences (ISSN 2455-4499)

<p>The adsorption of Cu2+ions on activated carbon based canarium schweinfurthii impregnated with ZnCl2 was studied. The shells of canarium schweinfurthii were impregnated with ZnCl2 at varying ZnCl2 concentrations, temperature, residence time while keeping the heating rate fixed at 10 °C / min and the ratio of impregnation of 1:1. The activated carbon with the highest surface area in term of iodine number of 860,817 mg/g, the highest methylene blue of 741,6 mg/g and 74,66 % of yield of carbon was obtained at 650 °C, 60 % ZnCl 2 and 30min. From the batch adsorption studies, the equilibrium time was found to be 40 min. Analysis of equilibrium isotherm models revealed a good correlation of the experimental data with the Tempkin (R 2 = 0.909) model. This confirms a high affinity of the activated carbon for Cu 2+ ions on the heterogeneous surface. The value of energy obtained from the Tempkin model was 60,606 J/mol and the presence of pics between 487 cm-1 to 871 cm-1 indicating that physisorption and chemisorption were taking place during this sorption. The pseudo-second order kinetics(R 2 = 0.999) governs the adsorption of Cu2+ions on this activated carbon.</p>

• #adsorption and biosorption for pollutant removal
• #activated carbon
• #adsorption
• #physisorption

Fenton-Like Oxidation of Acid Yellow 23 in the Presence of Iron Rich Soil

Tagne Guy Merlain, Lawrence Tatanah Nanganoa, Bélibi Bélibi Placide Désiré, Ndi Julius Nsami, Ketcha Joseph Mbadcam

Advances in Chemical Engineering and Science

Treatment of yellow dye 23 by heterogeneous Fenton-like process was studied using iron rich soil as an iron source. The iron rich soil sample was characterized by XRD, SEM and BET analysis. XRD pattern indicates that the iron rich soil is made of goethite and hematite. The reaction was systematically investigated under various experimental conditions such as pH, iron rich soil dosage, oxidant and dye concentrations. The result revealed that using iron rich soil as catalyst led to high discoloration efficiency (97.71% for 140 min of treatment) at pH = 2.5, 2 g/L iron rich soil and 16 m·mol/L H2O2. The degradation kinetics of acid yellow 23 can be described by a pseudo-first-order reaction following the Langmuir-Hinshelwood mechanism. The main roles of hydroxyl radicals in degradation process were investigated by adding of various radical scavengers.

• #advanced oxidation water treatment
• #electrochemical analysis and applications
• #iron oxide chemistry and applications
• #hematite

Removal Of Indigo Carmine Dye (Ic) By Batch Adsorption Method Onto Dried Cola Nut Shells And Its Active Carbon From Aqueous Medium

Ankoro Naphtali Odogu, Kouotou Daouda, Bélibi Bélibi Placide Désiré, Ndi Julius Nsami, Ketcha Joseph Mbadcam

Zenodo (CERN European Organization for Nuclear Research)

Natural cola nut shells and its active carbons were used to remove indigo carmine dye from aqueous solution using batch adsorption test. The effect of pH, contact time (t), adsorbent dose (m) and initial concentrations (Co) were investigated. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Tempkin and Dubin-Kaganer-Raduskushkevich classical isotherm models. This equilibrium data best fits with all the four isotherm models for cola nut shells. Langmuir and Freundlich equations correlated well with data obtained using activated carbon based H3PO4 while Freundlich and Tempkin best agreed with activated carbon based KOH. The kinetics of indigo carmine dye was discussed by pseudo-first order, pseudo-second order, Elovich and Intra-particle diffusion models. The pseudo-second order kinetic model equation fitted best to the data from all the three adsorbents. Elovich fitted best with data obtained using activated carbon based H3PO4 while intra-particle diffusion model for activated carbon based KOH. D-K-R shows that adsorption process was chemisorption for all the three adsorbents. Natural cola nut shells and activated carbon based KOH show higher adsorption capacities with indigo carmine compared to activated carbon based H3PO4. The results indicated that these shells and it active carbon can be used as an effective and low-cost adsorbent to remove indigo carmine from aqueous solutions

• #membrane separation technologies
• #indigo carmine
• #adsorption
• #nut

Kinetics and equilibrium studies of adsorption of phenol in aqueous solution onto activated carbon prepared from rice and coffee husks

Tchuifon Tchuifon, Donald Raoul, Anagho Solomon Gabche, Ketcha J. Mbadcam, Nche George Ndifor-Angwafor, Ndi Julius Nsami

Activated carbons obtained from the chemical activation of rice and coffee husks using H3PO4 were used to remove phenol from aqueous solution. Batch adsorption experiments were carried out and the amount of phenol adsorbed was determined as a function of adsorption time, pH of solution, adsorbent mass and initial concentration of phenol. The activated carbon used as adsorbent was characterized for its moisture content, bulk density, CHNS analysis, pH of zero point charge (pHpcz) and pH of the phenol solution. Some kinetics parameters were calculated; from kinetic results, the initial rate (obtained by pseudo second order) of adsorption is greater for all the adsorbent. The applicability of pseudo-second order model showed that the rate limiting step was chemisorption, involving forces caused by sharing or exchange of electrons between sorbent and sorbate. An Equilibrium study of the adsorption process showed that Langmuir isotherm described the isotherm data with high correlation coefficients on CAH2 and CAMH, while that of Temkin described that on CAH1. The values of energy obtained from the Temkin isotherm are also positive, this show that the adsorption process is exothermic. The results indicate that chemical rice husk and coffee husk activated carbon is suitable to be used as an adsorbent for phenol adsorption from aqueous solutions.

• #adsorption and biosorption for pollutant removal
• #adsorption
• #chemistry
• #activated carbon