COD AND AMMONIA REMOVAL FROM LANDFILL LEACHATE USING MIXED GRANULAR ADSORBENT MEDIA

Landfills generate leachate that contains elevated concentration of contaminants and is hazardous to human health and the ecosystem. In this study, the mixture of granular feldspar and cockle shells was investigated for remediation of COD and ammonia from landfill leachate. All adsorbent media were sieved to a particle size between 2.00 and 3.35 mm. The results revealed that the optimum mixing ratio of feldspar and cockle shells was 20:20, shaking speed was 150 rpm, pH level was 6, shaking time was 120 min, and dosage was 30 g. The adsorption isotherm analysis reveals that the Langmuir isotherm yielded the best fit to experimental data as compared to the Freundlich isotherm. The media produce encouraging results and can potentially be used as a good and sustainable adsorbent.

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Smart Design Nano-Hybrid Formulations by Machine Learning

Proceedings ◽

10.3390/iecp2020-08700 ◽

2020 ◽

Vol 78 (1) ◽

pp. 5

Author(s):

Raquel de Melo Barbosa ◽

Fabio Fonseca de Oliveira ◽

Gabriel Bezerra Motta Câmara ◽

Tulio Flavio Accioly de Lima e Moura ◽

Fernanda Nervo Raffin ◽

...

Keyword(s):

Machine Learning ◽

Experimental Data ◽

Water Solubility ◽

Inorganic Materials ◽

Fine Tuning ◽

Support Vector ◽

Drug Solubility ◽

Physical Behavior ◽

Best Fit

Nano-hybrid formulations combine organic and inorganic materials in self-assembled platforms for drug delivery. Laponite is a synthetic clay, biocompatible, and a guest of compounds. Poloxamines are amphiphilic four-armed compounds and have pH-sensitive and thermosensitive properties. The association of Laponite and Poloxamine can be used to improve attachment to drugs and to increase the solubility of β-Lapachone (β-Lap). β-Lap has antiviral, antiparasitic, antitumor, and anti-inflammatory properties. However, the low water solubility of β-Lap limits its clinical and medical applications. All samples were prepared by mixing Tetronic 1304 and LAP in a range of 1–20% (w/w) and 0–3% (w/w), respectively. The β-Lap solubility was analyzed by UV-vis spectrophotometry, and physical behavior was evaluated across a range of temperatures. The analysis of data consisted of response surface methodology (RMS), and two kinds of machine learning (ML): multilayer perceptron (MLP) and support vector machine (SVM). The ML techniques, generated from a training process based on experimental data, obtained the best correlation coefficient adjustment for drug solubility and adequate physical classifications of the systems. The SVM method presented the best fit results of β-Lap solubilization. In silico tools promoted fine-tuning, and near-experimental data show β-Lap solubility and classification of physical behavior to be an excellent strategy for use in developing new nano-hybrid platforms.

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Unbinding of Hyaluronan Accelerates the Enzymatic Activity of Bee Hyaluronidase

Journal of Biological Chemistry ◽

10.1074/jbc.m111.263731 ◽

2011 ◽

Vol 286 (41) ◽

pp. 35699-35707 ◽

Cited By ~ 2

Author(s):

Attila Iliás ◽

Károly Liliom ◽

Brigitte Greiderer-Kleinlercher ◽

Stephan Reitinger ◽

Günter Lepperdinger

Keyword(s):

Experimental Data ◽

Quartz Crystal ◽

Surface Loop ◽

X Ray ◽

Site Model ◽

Substrate Interaction ◽

Close Proximity ◽

Binding Groove ◽

The One ◽

Best Fit

Hyaluronan (HA), a polymeric glycosaminoglycan ubiquitously present in higher animals, is hydrolyzed by hyaluronidases (HAases). Here, we used bee HAase as a model enzyme to study the HA-HAase interaction. Located in close proximity to the active center, a bulky surface loop, which appears to obstruct one end of the substrate binding groove, was found to be functionally involved in HA turnover. To better understand kinetic changes in substrate interaction, binding of high molecular weight HA to catalytically inactive HAase was monitored by means of quartz crystal microbalance technology. Replacement of the delimiting loop by a tetrapeptide interconnection increased the affinity for HA up to 100-fold, with a KD below 1 nm being the highest affinity among HA-binding proteins surveyed so far. The experimental data of HA-HAase interaction were further validated showing best fit to the theoretically proposed sequential two-site model. Besides the one, which had been shown previously in course of x-ray structure determination, a previously unrecognized binding site works in conjunction with an unbinding loop that facilitates liberation of hydrolyzed HA.

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Comparative study of isotherm parameters of lead biosorption by two wastes of olive-oil production

Water Science & Technology ◽

10.2166/wst.2015.153 ◽

2015 ◽

Vol 72 (5) ◽

pp. 711-720 ◽

Cited By ~ 9

Author(s):

G. Blázquez ◽

A. Ronda ◽

M. A. Martín-Lara ◽

A. Pérez ◽

M. Calero

Keyword(s):

Experimental Data ◽

Olive Tree ◽

Langmuir Equation ◽

Equilibrium Isotherm ◽

Chemical Treatments ◽

Olive Stone ◽

Loss Of Mass ◽

Best Fit ◽

Tree Pruning ◽

Effectiveness Coefficient

Batch isotherm studies were carried out on a laboratory scale: (i) to investigate the effectiveness to remove lead of two wastes (olive stone (OS) and olive tree pruning (OTP)), untreated and chemically treated; and (ii) to examine the applicability of various adsorption isotherms to fit the experimental data. Results from tests were analyzed using seven equilibrium isotherm correlations (Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Redlich–Peterson, Sips, and Toth equations). The sum of the squares of the errors was determined for each isotherm and the Langmuir equation provided the best fit. Chemical treatments increased the biosorption properties of these materials. The maximum biosorption capacities were: 6.33, 49.13, 14.83, and 38.93 mg g−1 for untreated OS, HNO3-OS, H2SO4-OS, and NaOH-OS, respectively, and 26.72, 86.40, 72.78, and 123.80 mg g−1 for untreated OTP, HNO3-OTP, H2SO4-OTP, and NaOH-OTP, respectively. Finally, the loss of mass for each waste (13.9, 14.3, and 36.8% for HNO3-OS, H2SO4-OS, and NaOH-OS and 35.1, 27.5, and 46.7% for HNO3-OTP, H2SO4-OTP, and NaOH-OTP, respectively) was taken into account and an effectiveness coefficient was determined for each adsorbent material.

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A comparative study of lead adsorption by activated Khaya Ivoresnsis and Pycanthus Angolensis sawdust

Journal of Water Sanitation and Hygiene for Development ◽

10.2166/washdev.2016.070 ◽

2016 ◽

Vol 6 (4) ◽

pp. 593-601

Author(s):

Chidozie Charles Nnaji ◽

Stephen Chinwike Emefu

Keyword(s):

Experimental Data ◽

Freundlich Isotherm ◽

Intraparticle Diffusion ◽

Bulk Liquid ◽

Timber Species ◽

Particle Sizes ◽

Lead Adsorption ◽

Intraparticle Diffusion Model ◽

First Order Kinetics ◽

Good Agreement

Experiments investigating lead adsorption by activated sawdust of different particle sizes of two timber species were conducted. The experimental data were fitted to isothermal and kinetic models. The optimum particle size was 0.85 mm for Khaya ivorensis and 1.18 mm for Pycanthus angolensis. The adsorption of lead by Khaya ivorensis and Pycanthus angolensis conformed to the Langmuir isotherm (0.83 ≤ R2 ≤ 0.96 and 0.86 ≤ R2 ≤ 0.98, respectively) and Freundlich isotherm (0.69 ≤ R2 ≤ 0.97 and 0.94 ≤ R2 ≤ 1.0, respectively). The adsorption process for the two species of timber was controlled by solute transport in the bulk liquid and intraparticle diffusion which was confirmed by good agreement of experimental data with pseudo-first-order kinetics (0.96 ≤ R2 ≤ 1.0 for Khaya ivorensis and 0.9 ≤ R2 ≤ 1.0 for Pycanthus angolensis) and the intraparticle diffusion model (0.9 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.84 ≤ R2 ≤ 0.97 for Pycanthus angolensis). A new kinetic model was developed with R2 of 0.93 ≤ R2 ≤ 0.99 for Khaya ivorensis and 0.88 ≤ R2 ≤ 1.0 for Pycanthus angolensis.

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Palladium-Supported Zirconia-Based Catalytic Degradation of Rhodamine-B Dye from Wastewater

Water ◽

10.3390/w13111522 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1522

Author(s):

Salma Jabeen ◽

Muhammad Sufaid Khan ◽

Rozina Khattak ◽

Ivar Zekker ◽

Juris Burlakovs ◽

...

Keyword(s):

Catalytic Activity ◽

Rhodamine B ◽

Dye Degradation ◽

Freundlich Isotherm ◽

Impregnation Method ◽

K Value ◽

First Order Kinetics ◽

Good Catalytic Activity ◽

Rhodamine B Dye ◽

Best Fit

The catalytic activity of Pd/ZrO2 was studied in terms of the degradation of rhodamine-B dye in the presence of hydrogen peroxide. Pd/ZrO2 was prepared by impregnation method, calcined at 750 °C and characterized by XRD, SEM and EDX. The catalyst showed good catalytic activity for dye degradation at 333 K, using 0.05 g of the catalyst during 5 h. The reaction kinetics followed the pseudo-first order kinetics. The Freundlich, Langmuir and Temkin isotherms were applied to the data and the best fit was obtained with Freundlich isotherm. Thermodynamic parameters, like ΔH, ΔG and ΔS were also calculated. The negative values of ΔH (−291.406 KJ/mol) and Gibbs free energy (ΔG) showed the exothermic and spontaneous nature of the process. The positive ΔS (0.04832 KJ/mol K) value showed suitable affinity of catalyst for dye degradation. The catalyst was very stable, active and was easily separated from the reaction mixture by filtration. It can be concluded from the results that the prepared catalyst could be effectively used in dyes degradation/removal from water subjected to further validation and use for various dyes.

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Mathematical modeling and determination of thermodynamic properties of jabuticaba peel during the drying process

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v20n6p576-580 ◽

2016 ◽

Vol 20 (6) ◽

pp. 576-580 ◽

Cited By ~ 8

Author(s):

Cristian F. Costa ◽

Paulo C. Corrêa ◽

Jaime D. B. Vanegas ◽

Fernanda M. Baptestini ◽

Renata C. Campos ◽

...

Keyword(s):

Experimental Data ◽

Thermodynamic Properties ◽

Drying Process ◽

Drying Temperature ◽

Air Temperatures ◽

Nutritional Qualities ◽

Forced Air ◽

Air Circulation ◽

Best Fit

ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba) were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant as a function of temperature. The Midilli model showed the best fit to the experimental data of drying. The drying constant increased with the increment in drying temperature and promoted an activation energy of 37.29 kJ mol-1. Enthalpy and Gibbs free energy decreased with the increase in drying temperature, while entropy decreased and was negative.

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Drying kinetics of ‘babassu’ mesocarp

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n10p709-714 ◽

2017 ◽

Vol 21 (10) ◽

pp. 709-714 ◽

Cited By ~ 1

Author(s):

Jhonatas C. Rosa ◽

Andreza P. Mendonça ◽

Angélica dos S. Oliveira ◽

Sylviane B. Ribeiro ◽

Andréia do R. Batista ◽

...

Keyword(s):

Experimental Data ◽

Water Content ◽

Animal Feed ◽

Coefficient Of Determination ◽

Residual Distribution ◽

Solar Dryer ◽

Error Standard Deviation ◽

Forced Air ◽

Final Water Content ◽

Best Fit

ABSTRACT ‘Babassu’ mesocarp flour has been used by the pharmaceutical, human food and animal feed industries. However, there is lack of standardization in the production, as well as absence of information on the management of the product’s quality. Thus, the objective of this study was to dry the ‘babassu’ mesocarp in forced-air oven and solar dryer, adjust different mathematical models to the experimental data, as well as to quantify the levels of proteins and crude fiber of the produced flour. The criteria for the adjustment were the coefficient of determination, magnitude of the mean relative error, standard deviation of estimate and the residual distribution trend. Drying in the shortest time occurred in oven at 60 °C (370 min), leading to water content of 4.62%, while in the solar dryer the final water content was 8.07% in 6 days. The mathematical model Two Terms showed the best fit to the experimental data for oven drying and the Midilli model showed the best fit in solar dryer. There was an increase in protein content with the drying in solar dryer and oven at 40, 50 and 60 °C (1.36, 1.33, 1.15 and 1.37%, respectively) in relation to fresh mesocarp (0.88%). Drying in both oven and solar dryer promoted increase of protein in the flour.

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Multi-Component Adsorption of Benzene, Toluene, Ethylbenzene, and Xylene from Aqueous Solutions by Montmorillonite Modified with Tetradecyl Trimethyl Ammonium Bromide

Journal of Chemistry ◽

10.1155/2013/589354 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 15

Author(s):

H. Nourmoradi ◽

Mehdi Khiadani ◽

M. Nikaeen

Keyword(s):

Experimental Data ◽

Aqueous Solutions ◽

Structural Changes ◽

Freundlich Isotherm ◽

Isotherm Models ◽

Ammonium Bromide ◽

Order Kinetic ◽

Multicomponent Adsorption ◽

Benzene Toluene ◽

Kinetic And Isotherm Models

Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200% of the cation exchange capacity (CEC) of the adsorbent for a period of 24 h. The sorption of BTEX by TTAB-Mt was in the order ofB<T<E<X. The experimental data were fitted by many kinetic and isotherm models. The results also showed that the pseudo-second-order kinetic model and Freundlich isotherm model could, respectively, be fitted to the experimental data better than other available kinetic and isotherm models. The thermodynamic study indicated that the sorption of BTEX with TTAB-Mt was achieved spontaneously and the adsorption process was endothermic as well as physical in nature. The regeneration results of the adsorbent also showed that the adsorption capacity of adsorbent after one use was 51% to 70% of original TTAB-Mt.

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Mathematical modeling of pequi pulp drying and effective diffusivity determination

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n7p493-498 ◽

2017 ◽

Vol 21 (7) ◽

pp. 493-498 ◽

Cited By ~ 3

Author(s):

Elisabete P. de Sousa ◽

Rossana M. F. de Figueirêdo ◽

Josivanda P. Gomes ◽

Alexandre J. de M. Queiroz ◽

Deise S. de Castro ◽

...

Keyword(s):

Experimental Data ◽

Effective Diffusivity ◽

Drying Kinetics ◽

Convective Drying ◽

Drying Time ◽

Air Speed ◽

Drying Curves ◽

Increasing Temperature ◽

Kinetics Of ◽

Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

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Modelagem matemática da desidratação osmo-convectiva da palma forrageira (Opuntia fícus-indica Mill) utilizando soluções mistas

Revista Verde de Agroecologia e Desenvolvimento Sustentável ◽

10.18378/rvads.v10i4.3489 ◽

2015 ◽

Vol 10 (4) ◽

pp. 39

Author(s):

E. T. Silva ◽

E. C. O. Silva ◽

R. P. Gusmão ◽

J. D. Lopes ◽

T. A. S. Gusmão

Keyword(s):

Experimental Data ◽

Water Activity ◽

Osmotic Dehydration ◽

Convective Drying ◽

Human Consumption ◽

Cactus Pear ◽

Opuntia Ficus Indica ◽

Mixed Solutions ◽

Cut Resistance ◽

Best Fit

Objetivou-se nesse estudo avaliar a influência de pré-tratamentos osmóticos utilizando secagem convectiva complementar no processo de perda de água, ganho de sólidos e nos parâmetros de qualidade (cor, atividade de água e textura) de cladódios de palma forrageira. O Cladódio foi submetido à desidratação osmótica utilizando soluções mistas contendo 5% de NaCl e concentrações de sacarose de 50 e 60 °Brix, em diferentes proporções palma/solução (1:1, 1:4 e 1:10) a 40°C. Posteriormente foi realizada secagem convectiva a 50 e 60 °C. Foram utilizados, para ajuste aos dados experimentais da secagem, os modelos matemáticos de Page, Henderson & Pabis, Cavancanti Mata, Exponencial de Dois Termos e Midilli. O cladódio de palma in natura e desidratado foi caracterizado quanto aos parâmetros de cor, atividade de água e textura. O aumento da perda de massa foi proporcional ao aumento da proporção cladódio/solução utilizada na desidratação osmótica e o ganho de sólidos foi maior para a concentração de 50 °Brix. O modelo matemático de Midilli foi o que melhor se ajustou aos dados experimentais. Os parâmetros de cor, atividade de água e textura foram modificados pelas condições de desidratação osmótica e de secagem as quais o cladódio de palma foi submetido. O cladódio desidratado a 50 °C apresentou melhor preservação da cor, maior resistência ao corte e menor atividade de água. Mathematical modeling of osmo-convective dehydration of the cactus pear (Opuntia ficus-indica Mill) using mixed solutionsAbstract: The objective of this study was to evaluate the influence of osmotic pre-treatments with complementary convective drying in the water loss process and solids gain of cactus pear cladodes, to obtain palm for human consumption. The cladode was subjected to osmotic dehydration using mixed solutions containing 5% NaCl and sugar concentrations of 50 and 60 °Brix in different proportions palm/solution (1:1, 1:4 and 1:10) at 40 °C. Subsequently convective drying was performed at 50 and 60 °C. Were used to fit to the experimental data of drying, the mathematical models for Page, Henderson & Pabis, Cavancanti Mata, Exponential of Two Terms and Midilli. The spineless cactus in natura and dehydrated was characterized as the parameters: color, water activity and texture. The study noted that the increased of weight mass was proportional to the increased of proportion cladode/solution used in osmotic dehydration and the solids gain was higher for concentration of 50 °Brix. The Midilli mathematical model was the best fit to the experimental data. The parameters of color, water activity and texture were modified by the conditions of osmotic dehydration and drying which spineless cactus cladodes was submitted. The cactus cladode dehydrated at 50 °C presented better preservation of the color, increased cut resistance and lowest water activity.

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