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Engr. (Mrs.) Chinenye Adaobi Igwegbe (formerly Chinenye Adaobi Onyechi) is a lecturer in the Department of Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria. Her research interest is in Environment, Energy and Sustainability: Adsorption, Bio- and Electro- coagulation-flocculation, Waste Conversion, Material Characterization, Statistical Optimization, Stability studies, etc. She has published some articles in the same areas and is willing to exchange knowledge with other researchers.
To achieve sustainability, it is necessary to use proper treatment methods to reduce the pollutant loads of receiving waters. This study investigates the coagulative reduction of turbidity, COD, BOD and colour from aquaculture wastewater (AW) using a novel Garcinia kola seeds coagulant (GKC). This coagulant was obtained from extraction of Garcinia kola seeds and analysed for its spectral and morphological characteristics through FTIR and SEM. The kinetics of coagulation-flocculation were also investigated in terms of total dissolved and suspended solids (TDSP). The seeds had 11.27% protein and 68.33% carbohydrate, showing usability in adsorption/charges neutralisation as a coagulant to reduce particles. Maximal turbidity reduction = 81.93%, COD = 75.03%, BOD = 72.84% and colour = 56.69% at 0.3 g GKC/L, pH 2, 60 min and 303 K were achieved. Von Smoluchowski’s second-order peri-kinetics theory was used to fit the results, giving R2 > 0.9. At a coagulation order (α) of 2, the reaction rate (KC) and half-life (
Chinenye Adaobi Igwegbe; Joshua O. Ighalo; Okechukwu Dominic Onukwuli; Ifeoma Amaoge Obiora-Okafo; Ioannis Anastopoulos. Coagulation-Flocculation of Aquaculture Wastewater Using Green Coagulant from Garcinia kola Seeds: Parametric Studies, Kinetic Modelling and Cost Analysis. Sustainability 2021, 13, 9177 .
AMA StyleChinenye Adaobi Igwegbe, Joshua O. Ighalo, Okechukwu Dominic Onukwuli, Ifeoma Amaoge Obiora-Okafo, Ioannis Anastopoulos. Coagulation-Flocculation of Aquaculture Wastewater Using Green Coagulant from Garcinia kola Seeds: Parametric Studies, Kinetic Modelling and Cost Analysis. Sustainability. 2021; 13 (16):9177.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Joshua O. Ighalo; Okechukwu Dominic Onukwuli; Ifeoma Amaoge Obiora-Okafo; Ioannis Anastopoulos. 2021. "Coagulation-Flocculation of Aquaculture Wastewater Using Green Coagulant from Garcinia kola Seeds: Parametric Studies, Kinetic Modelling and Cost Analysis." Sustainability 13, no. 16: 9177.
Cationic dyes are toxic environmental pollutants that need to be mitigated from the aqueous environment. In this study, Hevea brasiliensis seed shells (HBSS) activated with H3PO4 (PHBSS) and NaCl (SHBSS) were explored for the removal of Congo red (CR) and malachite green (MG) from their aqueous solutions. The adsorbents were carbonised at 300 °C for 3 h and characterised by FTIR, SEM and XRF. Maximum removals for CR and MG were observed at pH 2 and pH 10, respectively. The uptake of both dyes was optimum at 0.3 mm particle size, 2 g/L adsorbent dosage and 100 mg/L initial dye concentration. The adsorption capacity of PHBSS and SHBSS to CR was 55.87 and 50.51 mg/g, respectively, while for MG was 58.48 and 56.82 mg/g, respectively. The study observed that the uptake of both dyes by both adsorbents was best fit to the Freundlich isotherm and the pseudo-second order kinetic model. The thermodynamics modelling revealed that the process was spontaneous and endothermic. The mechanism of CR and MG uptake was by a combination of electrostatic attraction, π–π electron–donor interaction, hydrogen bonds and pore diffusion. Furthermore, H3PO4 was a better activating agent for HBSS than NaCl given the current application.
Chinenye Adaobi Igwegbe; Joshua O. Ighalo; Kenechukwu Keluo Onyechi; Okechukwu Dominic Onukwuli. Adsorption of Congo red and malachite green using H3PO4 and NaCl-modified activated carbon from rubber (Hevea brasiliensis) seed shells. Sustainable Water Resources Management 2021, 7, 1 -16.
AMA StyleChinenye Adaobi Igwegbe, Joshua O. Ighalo, Kenechukwu Keluo Onyechi, Okechukwu Dominic Onukwuli. Adsorption of Congo red and malachite green using H3PO4 and NaCl-modified activated carbon from rubber (Hevea brasiliensis) seed shells. Sustainable Water Resources Management. 2021; 7 (4):1-16.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Joshua O. Ighalo; Kenechukwu Keluo Onyechi; Okechukwu Dominic Onukwuli. 2021. "Adsorption of Congo red and malachite green using H3PO4 and NaCl-modified activated carbon from rubber (Hevea brasiliensis) seed shells." Sustainable Water Resources Management 7, no. 4: 1-16.
The by-product from pistachio (Pistachia vera) has been valorised over the years as an adsorbent material for water treatment. The aim of this review was to synthesise the empirical findings on the uptake of different pollutants using adsorbents developed from pistachio waste. This was done to evaluate the progress of research on the subject matter, identify knowledge gaps and propose interesting areas for future work. Iran was observed to be a major source country (31%) of pistachio feedstock for adsorbent preparation. The highest reported specific surface area for pistachio adsorbent was 1884 m2/g for a carbon activated by NH4NO3 + NaOH and carbonised at 800 °C. Pistachio adsorbents showed very good removal efficiencies (> 90% in most cases) for both dyes, heavy metals, pharmaceuticals and other compounds. Isotherm and kinetics modelling was always best-fit to the classical Langmuir and Freundlich models and the pseudo-second-order kinetics model, respectively. HCl was the regularly used eluent for heavy metals desorption, while alkalis and organic acids were more regularly used for dyes. Interesting areas for future work include adsorbent preparation by physical activation, research interest in emerging contaminants, improvement of adsorbent desorption, utilisation of statistical physics modelling tools and the investigation of spent adsorbent disposal.
Chinenye Adaobi Igwegbe; Joshua O. Ighalo; Soumya Ghosh; Shahin Ahmadi; Victor I. Ugonabo. Pistachio (Pistacia vera) waste as adsorbent for wastewater treatment: a review. Biomass Conversion and Biorefinery 2021, 1 -19.
AMA StyleChinenye Adaobi Igwegbe, Joshua O. Ighalo, Soumya Ghosh, Shahin Ahmadi, Victor I. Ugonabo. Pistachio (Pistacia vera) waste as adsorbent for wastewater treatment: a review. Biomass Conversion and Biorefinery. 2021; ():1-19.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Joshua O. Ighalo; Soumya Ghosh; Shahin Ahmadi; Victor I. Ugonabo. 2021. "Pistachio (Pistacia vera) waste as adsorbent for wastewater treatment: a review." Biomass Conversion and Biorefinery , no. : 1-19.
Due to the negative environmental effect of methylene blue (MB), researchers have been investigating several aspects of its adsorption. The kinetics/rapidity is an important aspect of its uptake which is affected by the adsorbent pore properties. The aim of this study was to investigate the effect of pore size on the adsorption kinetics of methylene blue (MB). The paper employed a novel methodology where empirical findings across studies were summarised, analysed juxtaposed to derive observations. It was observed from the study that the kinetic constant increased as the pore size progressed from the macroporous to the mesoporous range. However, MB uptake was significantly slower for micropores. Microporous pore size leads to a drop in kinetic constant because the diffusion of MB through very small pores is restricted and gradual due to the adsorbate size. The mesoporous range is the superior pore size for MB adsorption kinetics. The Pseudo-second-order (PSO) model was best suited for all cases. However, 15% of the studies for mesoporous adsorbent had Pseudo-second-order (PFO) model as best-fit and 6% for microporous adsorbents. PSO is superior to PFO because it captures both the amount of active sites and the concentration of adsorbate as rate-limiting factors. It was observed that 10% of the studies had PFO as best-fit when linear modelling was used but 15% was best-fit with non-linear modelling. This was due to the mathematical simplicity of the linearised form of the PSO and the errors generally associated with the linearisation of kinetic models.
Joshua O. Ighalo; Kingsley O. Iwuozor; Chinenye Adaobi Igwegbe; Adewale George Adeniyi. Verification of Pore Size Effect on Aqueous-Phase Adsorption Kinetics: A Case Study of Methylene Blue. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2021, 626, 127119 .
AMA StyleJoshua O. Ighalo, Kingsley O. Iwuozor, Chinenye Adaobi Igwegbe, Adewale George Adeniyi. Verification of Pore Size Effect on Aqueous-Phase Adsorption Kinetics: A Case Study of Methylene Blue. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2021; 626 ():127119.
Chicago/Turabian StyleJoshua O. Ighalo; Kingsley O. Iwuozor; Chinenye Adaobi Igwegbe; Adewale George Adeniyi. 2021. "Verification of Pore Size Effect on Aqueous-Phase Adsorption Kinetics: A Case Study of Methylene Blue." Colloids and Surfaces A: Physicochemical and Engineering Aspects 626, no. : 127119.
Methylene blue (MB) is a heterocyclic aromatic compound used as a medication or as a synthetic dye for textiles. Due to its ecotoxicity, researchers have been investigating its mitigation by the adsorption process. The aim of this review was to analyse the performance of different classes of adsorbent for MB dye uptake based on their maximum adsorption capacity. MB was chosen for this analysis due to the large volume of work that has been done on it over the years. Over 500 research papers published on MB adsorption (within the past 5 years were analysed). This was to help guide the research area on the best class adsorbents for MB uptake thereby pointing the areas of biggest potential to investigators. Composites adsorbents (31%) were the most frequently studied for MB uptake. Other popularly used types were biosorbents (16%) and activated carbon (16%). Polymers and resins, and organic and inorganic nanoparticles were the more favoured constituents for composite adsorbent development. For similar data indices, composite adsorbents yielded a higher adsorption capacity. This suggests that composite adsorbents (especially with constituents of polymers, resins and nanoparticles) perform better for MB uptake. Though polymers and resins had the highest mean, the highest median was for activated carbon. Composite adsorbent was the second highest for mean, median and number of adsorbents above the 1000 mg/g threshold. It was surmised from the analysis that polymers, resins and composites are the best classes of adsorbents for MB uptake.
Kingsley O. Iwuozor; Joshua O. Ighalo; Lawal Adewale Ogunfowora; Adewale George Adeniyi; Chinenye Adaobi Igwegbe. An empirical literature analysis of adsorbent performance for methylene blue uptake from aqueous media. Journal of Environmental Chemical Engineering 2021, 9, 105658 .
AMA StyleKingsley O. Iwuozor, Joshua O. Ighalo, Lawal Adewale Ogunfowora, Adewale George Adeniyi, Chinenye Adaobi Igwegbe. An empirical literature analysis of adsorbent performance for methylene blue uptake from aqueous media. Journal of Environmental Chemical Engineering. 2021; 9 (4):105658.
Chicago/Turabian StyleKingsley O. Iwuozor; Joshua O. Ighalo; Lawal Adewale Ogunfowora; Adewale George Adeniyi; Chinenye Adaobi Igwegbe. 2021. "An empirical literature analysis of adsorbent performance for methylene blue uptake from aqueous media." Journal of Environmental Chemical Engineering 9, no. 4: 105658.
The treatment of municipal solid waste leachate using electrocoagulation–flocculation with metal electrodes: aluminium (Al) and iron (Fe) were investigated in this work. The feasibility of using this method for leachate treatment was determined in terms of turbidity, chemical oxygen demand (COD), and colour removal. The influence of pH, current dosage, electrolysis time, setting time, temperature and NaCl concentration on the process were examined. The effects of using the hybrid of Al and Fe in different arrangements (Al–Al, Fe–Fe, Fe–Al and Al–Fe) were also considered for the ECF process. The applicability of the perikinetic flocculation theory proposed by Von Smoluchowski was confirmed for the study through the regression coefficient (R2) values. The time evolution of aggregating particles or species was predicted. The properties of the sludge (flocs) were determined via the Fourier transform infrared (FTIR) analysis. The optimum pH using Al–Al, Fe–Fe, Al–Fe, and Fe–Al were 2, 4, 10 and 2, respectively. Al–Al electrode presented a higher turbidity removal (93.12%) and COD removal (75.28%) on the leachate than the other electrodes arrangements. Fe–Fe electrodes were the best for colour reduction (73.25%). The kinetic data obeyed the Brownian perikinetic flocculation theory. The mechanisms that accounted for the particle distribution evolution were both sweep flocculation and charge neutralisation. The FTIR results indicate that the particles were adsorbed from the leachate and no significant changes in the composition of the sludge were observed using the different electrode arrangements. The electrocoagulation–flocculation was very effective for pollutants reduction from municipal leachate.
Chinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Chinedu Josiah Umembamalu; Adewale George Adeniyi. Comparative analysis on the electrochemical reduction of colour, COD and turbidity from municipal solid waste leachate using aluminium, iron and hybrid electrodes. Sustainable Water Resources Management 2021, 7, 1 -18.
AMA StyleChinenye Adaobi Igwegbe, Okechukwu Dominic Onukwuli, Joshua O. Ighalo, Chinedu Josiah Umembamalu, Adewale George Adeniyi. Comparative analysis on the electrochemical reduction of colour, COD and turbidity from municipal solid waste leachate using aluminium, iron and hybrid electrodes. Sustainable Water Resources Management. 2021; 7 (3):1-18.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Chinedu Josiah Umembamalu; Adewale George Adeniyi. 2021. "Comparative analysis on the electrochemical reduction of colour, COD and turbidity from municipal solid waste leachate using aluminium, iron and hybrid electrodes." Sustainable Water Resources Management 7, no. 3: 1-18.
The aim of this review was to examine the adsorption of doxycycline (DC) from aqueous media. The review investigated the performance of various adsorbents, analysed the adsorption mechanism, and discussed the isotherm, kinetics, thermodynamics and other aspects of the adsorption process. Furthermore, the purpose of this review was also to identify knowledge gaps and future perspectives in the research area. DC has a proven ecotoxicological risk hence its mitigation from the environment through adsorption is justified. The highest reported adsorption capacity for DC is 835.45 mg/g for hierarchical CoFe2O4/bio-silica nanocomposite. The major mechanisms of DC uptake were electrostatic interaction and π-π interactions. DC was uptake was majorly best-fit to the Langmuir and Freundlich isotherm models, and the pseudo-second-order kinetics model. It was observed that DC is readily desorbed from various adsorbents and most of these can have >80% of the initial adsorption capacity retained after 4 cycles. Researchers on DC competitive adsorption have observed the salting-out effect, bridging effect and electrostatic screening effect. From this review, it can be concluded that DC can be efficiently mitigated from industrial effluents and wastewaters by the adsorption techniques.
Chukwunonso O. Aniagor; Chinenye Adaobi Igwegbe; Joshua O. Ighalo; Stephen N. Oba. Adsorption of doxycycline from aqueous media: A review. Journal of Molecular Liquids 2021, 334, 116124 .
AMA StyleChukwunonso O. Aniagor, Chinenye Adaobi Igwegbe, Joshua O. Ighalo, Stephen N. Oba. Adsorption of doxycycline from aqueous media: A review. Journal of Molecular Liquids. 2021; 334 ():116124.
Chicago/Turabian StyleChukwunonso O. Aniagor; Chinenye Adaobi Igwegbe; Joshua O. Ighalo; Stephen N. Oba. 2021. "Adsorption of doxycycline from aqueous media: A review." Journal of Molecular Liquids 334, no. : 116124.
In this study, the morphological characteristics of the T. neapolitana biofilms on a ceramic carrier, stainless steel, graphite foil, carbon paper, carbon felt and carbon cloth using 3D reconstruction technology was investigated. This was based on the micrographs available in Squadrito et al. (Data Brief 33: 106–403, 2020). Besides the ceramic carrier, the other surfaces were conductive and slightly positively polarised (0.8 and 1.2 V). A simple drying technique was used to show the biofilm and avoid its detachment while chemical fixing with glutaraldehyde was used to better highlight the bacterial morphology within the biofilm. The latter was more suitable for investigating biofilm morphology while the former for bacteria morphology. For the ceramic carrier and stainless steel electrode surfaces, a regular undulating pattern of the biofilm was highlighted by the 3D rendering whilst the glutaraldehyde fixed sample showed a rod-like bacteria morphology. For the other surfaces, a regular undulating pattern of the biofilm and a mixture of a rod-like and a coccoid form of settled bacteria were evidenced also. Carbon cloth was the more suitable electrode for the current application due to its richer filamentous network of bacteria biofilm suggesting a better prevention of bacteria detachment from the electrode surface. Indeed, a preserved biofilm was highlighted on the surfaces of the polarised carbon cloth.
Joshua O. Ighalo; Adewale George Adeniyi; Chinenye Adaobi Igwegbe. 3D reconstruction and morphological analysis of electrostimulated hyperthermophile biofilms of Thermotoga neapolitana. Biotechnology Letters 2021, 43, 1303 -1309.
AMA StyleJoshua O. Ighalo, Adewale George Adeniyi, Chinenye Adaobi Igwegbe. 3D reconstruction and morphological analysis of electrostimulated hyperthermophile biofilms of Thermotoga neapolitana. Biotechnology Letters. 2021; 43 (7):1303-1309.
Chicago/Turabian StyleJoshua O. Ighalo; Adewale George Adeniyi; Chinenye Adaobi Igwegbe. 2021. "3D reconstruction and morphological analysis of electrostimulated hyperthermophile biofilms of Thermotoga neapolitana." Biotechnology Letters 43, no. 7: 1303-1309.
The performance of Picralima nitida extract (PNE) in bio-coagulation-flocculation (BCF) for the reduction of chemical oxygen demand (COD) in municipal solid waste leachate (MSWL) was studied. The PNE was characterised via Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). The process was modelled using both the response surface methodology (RSM) and artificial neural network (ANN) methods, and their prognostic capabilities established. The coagulant precursor was found to contain protein (28.4%) which is an active component of a good coagulant for neutralisation and adsorption of the colloidal particles. C=O, O–H, and N-H functional groups were present in the extract which are preferred for BCF process. This process was effectively optimised (COD = 75.25±0.5%) to achieve the best removal at pH = 2.3, PNE dosage = 0.38 g/L, and time = 28.22. min. The analysis of variance indicated that the RSM model was statistically suitable for the interpretation of the processes at the studied range. The RSM and ANN were capable of predicting the COD reduction process with the latter giving the best prediction with lesser error and nonlinear relationship. Though ANN had superior accuracy, RSM has the advantage of giving a predictive equation and showing the effect of operating factors and their interactions on the response compared. The mechanisms of the process were charge neutralisation, adsorption and bridging.
Chinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Mathew Chukwudi Menkiti. Bio-coagulation-flocculation (BCF) of municipal solid waste leachate using Picralima nitida extract: RSM and ANN modelling. Current Research in Green and Sustainable Chemistry 2021, 4, 100078 .
AMA StyleChinenye Adaobi Igwegbe, Okechukwu Dominic Onukwuli, Joshua O. Ighalo, Mathew Chukwudi Menkiti. Bio-coagulation-flocculation (BCF) of municipal solid waste leachate using Picralima nitida extract: RSM and ANN modelling. Current Research in Green and Sustainable Chemistry. 2021; 4 ():100078.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Mathew Chukwudi Menkiti. 2021. "Bio-coagulation-flocculation (BCF) of municipal solid waste leachate using Picralima nitida extract: RSM and ANN modelling." Current Research in Green and Sustainable Chemistry 4, no. : 100078.
This work investigated the treatment of fish pond wastewater (FPW) using electrocoagulation – flocculation (ECF) through aluminium (Al) and iron (Fe) electro-coagulants. The feasibility of using this method has been determined in terms of turbidity (TUR), biochemical demand oxygen (BOD), chemical demand oxygen (COD), and reduction of colour (COL). The study analysed the role of pH, current dosage, electrolysis time, settling time, temperature, and concentration of NaCl on the ECF process. Also, the influence of using the hybrid of Al and Fe in different configurations (Al-Al, Fe-Fe, Fe-Al, and Al-Fe) was taken into account for the ECF process. The perikinetics kinetics of the process flocculation was studied. The coefficient of regression (R2) was used to confirm the theoretical applicability of perikinetics flocculation. The forecast of the time evolution of aggregating particles or species was included. The optimum pH was 2. Al-Al electrode had a higher TUR removal (87.87%). Fe-Fe electrodes were the best for reducing COL (73.56%). Al-Al was proven to be the best electrode configuration for BOD removal (76.90%) and COD removal (86.4 %). The ECF kinetic data partially followed Von Smoluchowski's equation for the Brownian perikinetics flocculation theory. The mechanisms that accounted for the distribution of particles were sweep flocculation and charge neutralisation. The ECF was very effective for reducing FPW pollutants.
Chinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Chinedu Josiah Umembamalu. Electrocoagulation-flocculation of aquaculture effluent using hybrid iron and aluminium electrodes: A comparative study. Chemical Engineering Journal Advances 2021, 6, 100107 .
AMA StyleChinenye Adaobi Igwegbe, Okechukwu Dominic Onukwuli, Joshua O. Ighalo, Chinedu Josiah Umembamalu. Electrocoagulation-flocculation of aquaculture effluent using hybrid iron and aluminium electrodes: A comparative study. Chemical Engineering Journal Advances. 2021; 6 ():100107.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Chinedu Josiah Umembamalu. 2021. "Electrocoagulation-flocculation of aquaculture effluent using hybrid iron and aluminium electrodes: A comparative study." Chemical Engineering Journal Advances 6, no. : 100107.
Naphthalene is a major component of tar whose formation is a technical barrier in gasification systems. It can be used for hydrogen production via the steam reforming process. In this study, artificial neural network was used to model the steam reforming of naphthalene. The dataset will be developed by non-stoichiometric computation of the minimisation of Gibbs free energy method. The effect of temperature and steam-to-oil ratio (STOR) on the selectivity of hydrogen gas, carbon dioxide, carbon monoxide and methane in the product stream was investigated. Temperature and STOR increase favoured H2 production in the steam reforming process. At the threshold of temperature > 600° C and STOR > 4 kg/kg, optimal H2 selectivity is achieved. The coefficient of determination and root mean squared error for the model for all regimes (training, validation and testing) and all synthesis gas constituents was > 0.99 and < 1 mol%, respectively. Parity plots revealed that the predictions were accurate at both high and low levels of prediction. Paired samples correlation revealed a strong positive correlation between model predictions and the experimental values. The current approach is unfavourable in scenarios where quick predictions and preliminary estimations are required other investigations in product and process development.
Chinenye Adaobi Igwegbe; Adewale George Adeniyi; Joshua O. Ighalo. ANN modelling of the steam reforming of naphthalene based on non-stoichiometric thermodynamic analysis. Chemical Papers 2021, 75, 3363 -3372.
AMA StyleChinenye Adaobi Igwegbe, Adewale George Adeniyi, Joshua O. Ighalo. ANN modelling of the steam reforming of naphthalene based on non-stoichiometric thermodynamic analysis. Chemical Papers. 2021; 75 (7):3363-3372.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Adewale George Adeniyi; Joshua O. Ighalo. 2021. "ANN modelling of the steam reforming of naphthalene based on non-stoichiometric thermodynamic analysis." Chemical Papers 75, no. 7: 3363-3372.
The aim of this work was to model, optimize, and compare fluoride removal by LaFeO3-NPs using the RSM (Response Surface Methodology), ANN (Artificial Neural Network), and GA (Genetic Algorithm) techniques.The input variables considered were pH, time, temperature, LaFeO3-NPs dose, and fluoride. The CCD (central composite design) plan was exercised for the analysis of RSM, and ANN to determine their capabilities of prediction of the response. Their performances were evaluated using the regression coefficient (R2), RMSE, SEP, and the AAD. Also, RSM and GA were used to maximize the response and their optimum conditions evaluated. Both RSM (R2 = 0.9970, AAD = 0.00001, RMSE = 0.0037, SEP = 0.0042) and ANN (R2 = 0.9919, AAD = 0.00044, RMSE = 0.0066, SEP = 0.0074) gave high degree of accuracy. The model equation obtained for the process through RSM was adequate. The GA and RSM gave very close values for the optimization of the fluoride reduction process; RSM gave optimum fluoride removal of 96.35% (at pH 8.6, time = 75.03 min, temperature = 34.9 °C, dose = 0.225 g, and concentration = 23.68 mg L−1) while the GA gave 96.30% (at pH 10, time = 120.39 min, temperature = 28.41 °C, dose = 1.030 g, and concentration = 16.31 mg L−1). But from the confirmation experiments, RSM and GA data gave 96.52% and 96.63%, respectively. RSM, ANN, and GA were capable of modeling and optimizing the elimination of fluoride using LaFeO3-NPs.
Shahin Ahmadi; Mohammad Mesbah; Chinenye Adaobi Igwegbe; Chukwuemeka Daniel Ezeliora; Christian Osagie; Nadeem A. Khan; Guilherme L. Dotto; Mehdi Salari; Mohammad Hadi Dehghani. Sono electro-chemical synthesis of LaFeO3 nanoparticles for the removal of fluoride: Optimization and modeling using RSM, ANN and GA tools. Journal of Environmental Chemical Engineering 2021, 9, 105320 .
AMA StyleShahin Ahmadi, Mohammad Mesbah, Chinenye Adaobi Igwegbe, Chukwuemeka Daniel Ezeliora, Christian Osagie, Nadeem A. Khan, Guilherme L. Dotto, Mehdi Salari, Mohammad Hadi Dehghani. Sono electro-chemical synthesis of LaFeO3 nanoparticles for the removal of fluoride: Optimization and modeling using RSM, ANN and GA tools. Journal of Environmental Chemical Engineering. 2021; 9 (4):105320.
Chicago/Turabian StyleShahin Ahmadi; Mohammad Mesbah; Chinenye Adaobi Igwegbe; Chukwuemeka Daniel Ezeliora; Christian Osagie; Nadeem A. Khan; Guilherme L. Dotto; Mehdi Salari; Mohammad Hadi Dehghani. 2021. "Sono electro-chemical synthesis of LaFeO3 nanoparticles for the removal of fluoride: Optimization and modeling using RSM, ANN and GA tools." Journal of Environmental Chemical Engineering 9, no. 4: 105320.
The aim of this study was to investigate the adsorption of Acid Blue 92 (AB92) dye onto single-walled carbon nanotubes (SWCNTs). The adsorbent was characterised by SEM, TEM, FTIR, and BET. The study comprised batch experiments conducted under varying conditions of dosage (0.01–0.2 g/L), time (10–180 min), pH (3–11), and dye initial concentration (10–200 mg/L). The optimum removal efficiency of 99.4% was achieved for AB92 at an adsorbent dosage of 0.12 g/L, dye initial concentration of 10 mg/L, pH of 3, and contact time of 75 min. The adsorption was best-fit to the pseudo-second order kinetics and Langmuir isotherm models. The monolayer adsorption capacity (qm) was 86.91 mg/g at 333 K. The activation energy of the system was 16.62 kJ/mol. Thermodynamics analysis revealed that the process was spontaneous (∆G0 was between −12.73 and −16.08 kJ/mol) and endothermic (∆H0 = 2.51 kJ/mol). The positive ∆S0 value (0.055 kJ/mol K) also suggests the affinity of the SWCNTs adsorbent for AB92. The mechanism of AB92 dye uptake by SWCNTs was majorly by hydrogen bonds, dipole-induced dipole bonds, London dispersion interactions, π-π acceptor–donor interactions, and the hydrophobic effect. The results reveal that SWCNTs is an effective adsorbent for AB92 removal from industrial effluents and wastewater. • Removal of Acid Blue 92 by single-walled carbon nanotubes (SWCNTs) was examined. • The SWCNTs at dosage of 0.12 g/L removed 99.4% of the dye within 75 min at pH 3. • The pseudo-second order kinetics and Langmuir isotherm equations explained the process.
Davoud Balarak; Mohadeseh Zafariyan; Chinenye Adaobi Igwegbe; Kenechukwu Keluo Onyechi; Joshua O. Ighalo. Adsorption of Acid Blue 92 Dye from Aqueous Solutions by Single-Walled Carbon Nanotubes: Isothermal, Kinetic, and Thermodynamic Studies. Environmental Processes 2021, 8, 869 -888.
AMA StyleDavoud Balarak, Mohadeseh Zafariyan, Chinenye Adaobi Igwegbe, Kenechukwu Keluo Onyechi, Joshua O. Ighalo. Adsorption of Acid Blue 92 Dye from Aqueous Solutions by Single-Walled Carbon Nanotubes: Isothermal, Kinetic, and Thermodynamic Studies. Environmental Processes. 2021; 8 (2):869-888.
Chicago/Turabian StyleDavoud Balarak; Mohadeseh Zafariyan; Chinenye Adaobi Igwegbe; Kenechukwu Keluo Onyechi; Joshua O. Ighalo. 2021. "Adsorption of Acid Blue 92 Dye from Aqueous Solutions by Single-Walled Carbon Nanotubes: Isothermal, Kinetic, and Thermodynamic Studies." Environmental Processes 8, no. 2: 869-888.
Herbicides and pesticides (H & P) are commonly used in agricultural practice and is a serious environmental pollutant in contemporary times. Studies have shown that it can be efficiently mitigated from the environment by adsorption. The aim of this study was to utilise Artificial Neural Networks (ANN) to model the adsorption of H & P from aqueous media based on the sorbate-sorbent interphase. The sorbate-sorbent interphase was characterised by the relative molecular mass (g/mol), specific surface area (m2/g), effective surface area (mol/m2), solubility (mol/l), and preferential adsorption (sorbate mol on sorbent/sorbate mol in solution). The coefficient of determination (R2) at training, validation and testing were 0.9825, 0.9428 and 0.9793 respectively. The accuracy of the model was substantiated by direct comparison and parity plots. The paired samples correlation showed a strong positive correlation (0.980) and statistical significance (p < 0.05) between the model predictions and experimental results. This study reveals that information on the adsorbent specific surface area, adsorbent effective surface area, adsorbate preferential adsorption, adsorbate solubility and adsorbate relative molecular mass can be used to accurately predict the mass adsorption capacity for any H & P from aqueous media.
Adewale George Adeniyi; Chinenye Adaobi Igwegbe; Joshua O. Ighalo. ANN Modelling of the Adsorption of Herbicides and Pesticides Based on Sorbate-Sorbent Interphase. Chemistry Africa 2021, 4, 443 -449.
AMA StyleAdewale George Adeniyi, Chinenye Adaobi Igwegbe, Joshua O. Ighalo. ANN Modelling of the Adsorption of Herbicides and Pesticides Based on Sorbate-Sorbent Interphase. Chemistry Africa. 2021; 4 (2):443-449.
Chicago/Turabian StyleAdewale George Adeniyi; Chinenye Adaobi Igwegbe; Joshua O. Ighalo. 2021. "ANN Modelling of the Adsorption of Herbicides and Pesticides Based on Sorbate-Sorbent Interphase." Chemistry Africa 4, no. 2: 443-449.
The research described here aimed to model the water absorption behavior of reinforced polystyrene (PS) composites developed from powders of plantain peel (PPC) and bamboo fiber (BFC) using the Artificial Neural Network (ANN) model. The composites were developed by manual mixing and hand layup at room temperature (25 ± 2 °C) and cured by open molding at room temperature for 7 days. Water absorption tests were performed according to the ASTM standard method (D1037-99, ASTM, 1999). The water absorption was observed to increase with both filler loading and immersion time for both PPC and BFC. The coefficient of determination (R 2) values >0.98 were achieved for training, validation, and testing for both composite types. The model results showed low root mean squared error values (<1 wt%), revealing that in the utilization of the model a high accuracy threshold was expected for the ANN predictions. Parity plots revealed that the models gave a good balance between over-predictions and under-predictions and the accuracy could be substantiated both at low and high water absorption prediction values. ANOVA revealed that the results were statistically significant at a significance level of p < 0.05.
Joshua O. Ighalo; Chinenye Adaobi Igwegbe; Adewale George Adeniyi; Sulyman A. Abdulkareem. Artificial Neural Network Modeling of the Water Absorption Behavior of Plantain Peel and Bamboo Fibers Reinforced Polystyrene Composites. Journal of Macromolecular Science, Part B 2021, 60, 472 -484.
AMA StyleJoshua O. Ighalo, Chinenye Adaobi Igwegbe, Adewale George Adeniyi, Sulyman A. Abdulkareem. Artificial Neural Network Modeling of the Water Absorption Behavior of Plantain Peel and Bamboo Fibers Reinforced Polystyrene Composites. Journal of Macromolecular Science, Part B. 2021; 60 (7):472-484.
Chicago/Turabian StyleJoshua O. Ighalo; Chinenye Adaobi Igwegbe; Adewale George Adeniyi; Sulyman A. Abdulkareem. 2021. "Artificial Neural Network Modeling of the Water Absorption Behavior of Plantain Peel and Bamboo Fibers Reinforced Polystyrene Composites." Journal of Macromolecular Science, Part B 60, no. 7: 472-484.
Penicillins (PENs) are β-lactam antibiotics with significant environmental toxicology. This review aimed to synthesise the research efforts on the removal of PENs via a variety of separation, degradation and biological processes. It was observed that isotropic microporous microfiltration membranes are not effective for rejecting PENs, due to their large uniform pore size distribution. Researchers favoured the application of Nanofiltration membrane and adsorption as separation technologies. Carbon-based adsorbents were the most efficient class of adsorbents for PENs removal from water. Lewis acid-base interactions, hydrogen bonding, electrostatic attraction and π – π interactions were the main adsorption mechanisms. Generally, the ultraviolet irradiation assisted-advanced oxidation processes (AOPs) and the Fenton-like processes outperformed the electrochemical and ultrasonic assisted-AOPs for PENs degradation. AOPs must be incorporated with other methods of treatment to minimise potential costs in terms of energy, time, equipment, and chemicals. For biological processes for PENs removal, anaerobic treatment processes were observed to be more efficient for the removal of PENs than aerobic processes. With the exception of microfiltration and electrocoagulation, most other processes were found to be effective for the removal of PENs from water, albeit with some disadvantages. From the review, it can be surmised that there has been great research progress on the subject and many new findings have been obtained in recent times though there is still much work to be done.
Joshua O. Ighalo; Chinenye Adaobi Igwegbe; Chukwunonso O. Aniagor; Stephen N. Oba. A review of methods for the removal of penicillins from water. Journal of Water Process Engineering 2020, 39, 101886 .
AMA StyleJoshua O. Ighalo, Chinenye Adaobi Igwegbe, Chukwunonso O. Aniagor, Stephen N. Oba. A review of methods for the removal of penicillins from water. Journal of Water Process Engineering. 2020; 39 ():101886.
Chicago/Turabian StyleJoshua O. Ighalo; Chinenye Adaobi Igwegbe; Chukwunonso O. Aniagor; Stephen N. Oba. 2020. "A review of methods for the removal of penicillins from water." Journal of Water Process Engineering 39, no. : 101886.
The discharge of oil and grease (O&G) containing effluent without treatment may contaminate the aquatic environs and freshwater. The removal of O&G from simulated refinery desalter effluent (SRDE) by activated carbon (AC) originated from chemical activation/carbonization of corn cobs (CCs) was investigated through fixed-bed column studies. The corn cobs activated carbon (CCAC) was characterized to determine its physicochemical properties, and the functional groups presently active on it partaking in the column adsorption process. The CCAC size (150, 300 and 600 µm), initial adsorbate concentration (200, 300 and 400 mg/L), and bed height (100, 200 and 300 mm) were varied to observe their influence on the adsorption of O&G and breakthrough time (τ) at a constant flow rate of 10.5 mL/min in a 10 mm diameter column of length: 60 mm. The removal of O&G from SRDE was inspected using the Bohart-Adams (B-A) and Yoon-and-Nelson (Y-N) kinetic models. Breakthrough time and %O&G removal decreased with increasing CCAC particle size and feed concentration and improved with rising bed height (BH). The void fractions (ε) at BHs of 100, 200 and 300 mm were 0.0247, 0.0124 and 0.0082, respectively. The ideal residence time (tR ) was 4.49 min. The B-A model yielded the highest degree of fit to the data than the Y-N model with R2 within 0.8217 and 0.9771. This means that the B-A model can be used to predict the breakthrough curve of any desired values for the present study. This work also revealed that CCs could be packed in a fixed-bed column for O&G reduction from refinery desalter effluent.
Chinenye Adaobi Igwegbe; Chinedu Josiah Umembamalu; Emmanuel Ugochukwu Osuagwu; Stephen N. Oba; Lovet N. Emembolu. Studies on Adsorption Characteristics of Corn Cobs Activated Carbon for the Removal of Oil and Grease from Oil Refinery Desalter Effluent in a Downflow Fixed Bed Adsorption Equipment. European Journal of Sustainable Development Research 2020, 5, em0145 .
AMA StyleChinenye Adaobi Igwegbe, Chinedu Josiah Umembamalu, Emmanuel Ugochukwu Osuagwu, Stephen N. Oba, Lovet N. Emembolu. Studies on Adsorption Characteristics of Corn Cobs Activated Carbon for the Removal of Oil and Grease from Oil Refinery Desalter Effluent in a Downflow Fixed Bed Adsorption Equipment. European Journal of Sustainable Development Research. 2020; 5 (1):em0145.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Chinedu Josiah Umembamalu; Emmanuel Ugochukwu Osuagwu; Stephen N. Oba; Lovet N. Emembolu. 2020. "Studies on Adsorption Characteristics of Corn Cobs Activated Carbon for the Removal of Oil and Grease from Oil Refinery Desalter Effluent in a Downflow Fixed Bed Adsorption Equipment." European Journal of Sustainable Development Research 5, no. 1: em0145.
In this paper, the adsorption of Ciprofloxacin (CIP) from water in studies over the last decade was reviewed. The purpose of this review is to analyse the vast body of literature on the subject, identify key empirical findings on specific investigation domains, establish knowledge gaps and grey areas that could serve as a foundation for other investigations by researchers and predict future perspectives in the research area. The highest reported adsorption capacity for CIP was 1564 mg/g for magnetic N-doped porous carbon. The major mechanisms of CIP uptake are electrostatic interactions, π-π interactions, H-bonds, hydrophobic interactions and pore diffusion. CIP uptake was best-fit to either the Langmuir and Freundlich isotherm and the pseudo-second-order kinetic model. For most adsorbent types, reusability of up to 4 cycles could be achieved with good retention of uptake capacity. The review further showed that CIP uptake in adsorption columns was majorly best fitted to the Thomas and Yoon-Nelson models. In competitive adsorption scenarios, the presence of other pharmaceuticals usually decreases the uptake of CIP. Looking to the future, studies on novel hybrid processes, adsorbent modification, composite adsorbent development, neural network modelling, molecular simulations and used adsorbent disposal techniques are likely to increase for CIP adsorption.
Chinenye Adaobi Igwegbe; Stephen N. Oba; Chukwunonso O. Aniagor; Adewale George Adeniyi; Joshua O. Ighalo. Adsorption of ciprofloxacin from water: A comprehensive review. Journal of Industrial and Engineering Chemistry 2020, 93, 57 -77.
AMA StyleChinenye Adaobi Igwegbe, Stephen N. Oba, Chukwunonso O. Aniagor, Adewale George Adeniyi, Joshua O. Ighalo. Adsorption of ciprofloxacin from water: A comprehensive review. Journal of Industrial and Engineering Chemistry. 2020; 93 ():57-77.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Stephen N. Oba; Chukwunonso O. Aniagor; Adewale George Adeniyi; Joshua O. Ighalo. 2020. "Adsorption of ciprofloxacin from water: A comprehensive review." Journal of Industrial and Engineering Chemistry 93, no. : 57-77.
The aim of this study was to investigate the adsorption of Congo red (CR) and Vat yellow 4 (VY4) cationic dyes from aqueous media using adsorbents developed from Dacryodes edulis (African pear) seeds (DES) activated using phosphoric acid (H3PO4) and sodium chloride (NaCl). The adsorbents were characterised using X-ray Fluorescence (XRF), Fourier Transforms Infrared Spectrophotometry (FTIR) and Scanning Electron Microscopy (SEM). Maximum uptake of CR and VY4 was observed at an initial pH of 2. H3PO4 activated Dacryodes edulis carbon (ADES) performed better than the NaCl activated Dacryodes edulis carbon (SDES) which implied that the H3PO4 increased the porosity and surface area of DES compared to NaCl use. Maximum dye removal of 99.59%, 96.88%, 99.70% and 98.99% were obtained for the VY4/ADES, VY4/SDES, CR/ADES and CR/SDES, respectively. The Langmuir-Freundlich isotherm showed best fitting when using ADES as adsorbent and the Freundlich isotherm when using SDES. The pseudo-second-order kinetic model was found to best correlate with the experimental data and the adsorption process was controlled by film diffusion. Thermodynamics revealed that adsorption was favourable, spontaneous, and endothermic.
Chinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Patrick Ugochukwu Okoye. Adsorption of Cationic Dyes on Dacryodes edulis Seeds Activated Carbon Modified Using Phosphoric Acid and Sodium Chloride. Environmental Processes 2020, 7, 1151 -1171.
AMA StyleChinenye Adaobi Igwegbe, Okechukwu Dominic Onukwuli, Joshua O. Ighalo, Patrick Ugochukwu Okoye. Adsorption of Cationic Dyes on Dacryodes edulis Seeds Activated Carbon Modified Using Phosphoric Acid and Sodium Chloride. Environmental Processes. 2020; 7 (4):1151-1171.
Chicago/Turabian StyleChinenye Adaobi Igwegbe; Okechukwu Dominic Onukwuli; Joshua O. Ighalo; Patrick Ugochukwu Okoye. 2020. "Adsorption of Cationic Dyes on Dacryodes edulis Seeds Activated Carbon Modified Using Phosphoric Acid and Sodium Chloride." Environmental Processes 7, no. 4: 1151-1171.
In the present work, praseodymium-doped cadmium tungstate (Pr-CdWO4) nanoparticles were synthesized, characterized and used as catalysts in a sonocatalytic process to degrade the toxic synthetic azo dye Remazol Black B (RBB). RBB was degraded by 93.9% operating at optimal conditions (pH=3, C=100 mg/L, catalyst dosage=0.35 g/L, T=298 K and irradiation time100 min) under an ultrasonic bath at 60 kHz. Further, the addition of different radical scavengers and enhancers to the reaction was assessed. It was found that the addition of the radical scavengers sodium sulfate, sodium carbonate, and sodium chloride decreased RBB degradation from 93.9% to 86.0%, 78.0%, and 71.2%, respectively. On the contrary, the addition of the enhancers potassium periodate, peroxydisulfate and hydrogen peroxide slightly increased the RBB degradation from 93.9% to 95.3%, 96.1%, and 98.7%, respectively. The sonocatalytic process resulted in higher RBB degradation than by applying separately sonolysis (34.7%) and the catalyst as an adsorbent (39.5%). The experimental data followed both the pseudo-first-order (PFO) and Langmuir-Hinshelwood (L-H) kinetics models. However, the PFO gave better fitting (R2=0.993) than the L-H kinetic model (R2=0.9025) at the same optimum experimental conditions. The obtained results pointed out the sonocatalytic process with Pr-doped CdWO4 nanoparticles as a promising process for the degradation of azo dyes and other hazardous organic compounds existing in wastewater.
Shahin Ahmadi; Abbas Rahdar; Chinenye Adaobi Igwegbe; Sobhan Mortazavi-Derazkola; Artur Marek Banach; Somayeh Rahdar; Ajaya Kumar Singh; Susana Rodriguez-Couto; George Z. Kyzas. Praseodymium-doped cadmium tungstate (CdWO4) nanoparticles for dye degradation with sonocatalytic process. Polyhedron 2020, 190, 114792 .
AMA StyleShahin Ahmadi, Abbas Rahdar, Chinenye Adaobi Igwegbe, Sobhan Mortazavi-Derazkola, Artur Marek Banach, Somayeh Rahdar, Ajaya Kumar Singh, Susana Rodriguez-Couto, George Z. Kyzas. Praseodymium-doped cadmium tungstate (CdWO4) nanoparticles for dye degradation with sonocatalytic process. Polyhedron. 2020; 190 ():114792.
Chicago/Turabian StyleShahin Ahmadi; Abbas Rahdar; Chinenye Adaobi Igwegbe; Sobhan Mortazavi-Derazkola; Artur Marek Banach; Somayeh Rahdar; Ajaya Kumar Singh; Susana Rodriguez-Couto; George Z. Kyzas. 2020. "Praseodymium-doped cadmium tungstate (CdWO4) nanoparticles for dye degradation with sonocatalytic process." Polyhedron 190, no. : 114792.