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1.
ACS Omega ; 9(7): 7986-8004, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38405456

RESUMEN

In the quest for eco-conscious innovations, this research was designed for the sustainable synthesis of magnetite (Fe3O4) nanoparticles, using ferric chloride hexahydrate salt as a precursor and extract of Eucalyptus globulus leaves as both a reducing and capping agent, which are innovatively applied as a photocatalyst for the photocatalytic degradation of antibiotics "ciprofloxacin and amoxicillin". Sugar cane bagasse biomass, sugar cane bagasse pyrolyzed biochar, and magnetite/sugar cane bagasse biochar nanocomposite were also synthesized via environmentally friendly organized approaches. The optimum conditions for the degradation of ciprofloxacin and amoxicillin were found to be pH 6 for ciprofloxacin and 5 for amoxicillin, dosage of the photocatalyst (0.12 g), concentration (100 mg/L), and irradiation time (240 min). The maximum efficiencies of percentage degradation for ciprofloxacin and amoxicillin were found to be (73.51%) > (63.73%) > (54.57%) and (74.07%) > (61.55%) > (50.66%) for magnetic nanocomposites, biochar, and magnetic nanoparticles, respectively. All catalysts demonstrated favorable performance; however, the "magnetite/SCB biochar" nanocomposite exhibited the most promising results among the various catalysts employed in the photocatalytic degradation of antibiotics. Kinetic studies for the degradation of antibiotics were also performed, and notably, the pseudo-first-order chemical reaction showed the best results for the degradation of antibiotics. Through a comprehensive and comparative analysis of three unique photocatalysts, this research identified optimal conditions for efficient treatment of drug-contaminated wastewater, thus amplifying the practical significance of the findings. The recycling of magnetic nanoparticles through magnetic separation, coupled with their functional modification for integration into composite materials, holds significant application potential in the degradation of antibiotics.

2.
Nanomaterials (Basel) ; 12(16)2022 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-36014692

RESUMEN

To meet the current challenges concerning the removal of dyes from wastewater, an environmentally friendly and efficient treatment technology is urgently needed. The recalcitrant, noxious, carcinogenic and mutagenic compound dyes are a threat to ecology and its removal from textile wastewater is challenge in the current world. Herein, biochar-mediated zirconium ferrite nanocomposites (BC-ZrFe2O5 NCs) were fabricated with wheat straw-derived biochar and applied for the adsorptive elimination of Tartrazine dye from textile wastewater. The optical and structural properties of synthesized BC-ZrFe2O5 NCs were characterized via UV/Vis spectroscopy, Fourier transform Infra-red (FTIR), X-Ray diffraction (XRD), Energy dispersive R-Ray (EDX) and Scanning electron microscopy (SEM). The batch modes experiments were executed to explore sorption capacity of BC-ZrFe2O5 NCs at varying operative conditions, i.e., pH, temperature, contact time, initial dye concentrations and adsorbent dose. BC-ZrFe2O5 NCs exhibited the highest sorption efficiency among all adsorbents (wheat straw biomass (WSBM), wheat straw biochar (WSBC) and BC-ZrFe2O5 NCs), having an adsorption capacity of (mg g-1) 53.64 ± 0.23, 79.49 ± 0.21 and 89.22 ± 0.31, respectively, for Tartrazine dye at optimum conditions of environmental variables: pH 2, dose rate 0.05 g, temperature 303 K, time of contact 360 min and concentration 100 mg L-1. For the optimization of process variables, response surface methodology (RSM) was employed. In order to study the kinetics and the mechanism of the adsorption process, kinetic and equilibrium mathematical models were used, and results revealed 2nd order kinetics and a multilayer chemisorption mechanism due to complexation of hydroxyl, Fe and Zr with dyes functional groups. The nanocomposites were also recovered in five cycles without significant loss (89 to 63%) in adsorption efficacy. This research work provides insight into the fabrication of nanoadsorbents for the efficient adsorption of Tartrazine dye, which can also be employed for practical engineering applications on an industrial scale as efficient and cost effective materials.

3.
Polymers (Basel) ; 14(13)2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35808688

RESUMEN

In this research work, a simple, efficient, and eco-friendly procedure for the biosorption of Cr(VI) ions was studied. A detailed comparative study was performed to check the adsorption efficiency of agrowaste (banana and potato peels)-based adsorbents. Firstly, mixed biosorbent was washed, dried and ground into powder, secondly, biosorbent was pyrolyzed into biochar and thirdly TiO2 nanocomposite (TiO2 NC) biosorbent was made by sonicating using prepared biochar and TiO2 NPs. Titanium dioxide nanoparticles (TiO2 NPs) were synthesized by a green method using Psidium guajava leaf extract. The synthesized adsorbents were characterized by SEM, EDX FT-IR, XRD and UV-visible analysis. The effect of four different factors, i.e., pH of the synthetic metallic solution, time, concentration and adsorbent dosage was studied. The optimum conditions were time (120 min), pH (3), concentration (10 ppm) and adsorbent dosage (1.0 g). The kinetic modeling showed that the adsorption of Cr(VI) ion follows a pseudo second-order mechanism and the Langmuir isotherm model was found to fit better for this study. Response surface methodology (RSM)-based optimized parameters provided optimal parameter sets that better represent the adsorption rate models. The uptake capacity of Cr(VI) from aqueous solution was found to be biomass (76.49 mg/L) ˂ biochar (86.51 mg/L) ˂ TiO2 NC (92.89 mg/L). It can be suggested that the produced TiO2 NC could possibly be an efficient biosorbent for the removal of Cr(IV).

4.
Biomed Res Int ; 2022: 6865472, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35865666

RESUMEN

Betamethasone is an important glucocorticoids (GCs), frequently used to cure allergies (such as asthma and angioedema), Crohn's disease, skin diseases (such as dermatitis and psoriasis), systemic lupus erythematosus, rheumatic disorders, and leukemia. Present investigation deals to find potential agonist of glucocorticoid receptors after biotransformation of betamethasone dipropionate (1) and to carry out the molecular docking and ADME analyses. Biotransformation of 1 was carried out with Launaea capitata (dandy) roots and Musa acuminate (banana) leaves. M. acuminate furnished low-cost value-added products such as Sananone dipropionate (2) in 5% yields. Further, biocatalysis of Sananone dipropionate (2) with M. acuminate gave Sananone propionate (3) and Sananone (4) in 12% and 7% yields, respectively. However, Sananone (4) was obtained in 37% yields from Launaea capitata. Compound 5 was obtained in 11% yield after ß-elimination of propionic acid at C-17 during oxidation of compound 1. The structure elucidation of new compounds 2-5 was accomplished through combined use of X-ray diffraction and NMR (1D and 2D) studies. In addition to this, molecular docking and ADME analyses of all transformed products of 1 were also done. Compounds 1-5 showed -12.53 to -10.11 kcal/mol potential binding affinity with glucocorticoid receptor (GR) and good ADME profile. Moreover, all the compounds showed good oral bioavailability with the octanol/water partition coefficient in the range of 2.23 to 3.65, which indicated that compounds 1-5 were in significant agreement with the given criteria to be considered as drug-like.


Asunto(s)
Fármacos Dermatológicos , Psoriasis , Betametasona/análogos & derivados , Biotransformación , Fármacos Dermatológicos/uso terapéutico , Humanos , Simulación del Acoplamiento Molecular , Psoriasis/tratamiento farmacológico , Receptores de Glucocorticoides
5.
Comput Biol Chem ; 95: 107591, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34702631

RESUMEN

N-heterocyclic carbene (NHC) adducts have shown remarkable biological potential for numerous medical applications. With an aim to improve biological potential of benzimidazolium salts, newer analogues of benzimidazole and their silver complexes were synthesized and characterized. Synthesized salts (L1-L2) and silver complexes (C1-C2) were confirmed through elemental analysis, UV-visible spectroscopy, FTIR, 1H NMR & 13C NMR spectroscopy. The compounds C1 & C2 were found stable in solution form for studied time period when examined spectroscopically and showed optimum lipophilicity when measured for their partition coefficient through flask shake method. Synthesized compounds showed good antimicrobial potential against gram positive bacterial strain S. Aureus with IC50 2.02±0.12 and 2.11±0.13 µM respectively while 2.11±0.1 and 2.28±0.17 µM against gram negative bacterial strain E. Coli for C1 and C2 respectively. The interaction study of the related compounds with DNA was predicted by molecular docking study, which confirmed that the studied compound C1 (-8.04 kcal/mol) has a higher binding energy than compound C2 (-4.23 kcal/mol); Also, the compound C1 exhibits a better affinity against to DNA than Ethidium bromide (-7.68 kcal/mol) and cisplatin (-6.21 kcal/mol).The claim was practically assured through spectroscopic and viscometeric method which confirmed that compounds have good affinity for DNA with binding constant kb, 5.78×104 M-1 and 6.84×104 M-1 for C1 and C2 respectively.


Asunto(s)
Antibacterianos/farmacología , Antioxidantes/farmacología , ADN/química , Teoría Funcional de la Densidad , Compuestos Heterocíclicos/farmacología , Metano/análogos & derivados , Animales , Antibacterianos/síntesis química , Antibacterianos/química , Antioxidantes/síntesis química , Antioxidantes/química , Compuestos de Bifenilo/antagonistas & inhibidores , Bovinos , Diseño de Fármacos , Escherichia coli/efectos de los fármacos , Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/química , Metano/química , Metano/farmacología , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Estructura Molecular , Picratos/antagonistas & inhibidores , Staphylococcus aureus/efectos de los fármacos , Viscosidad
6.
Water Sci Technol ; 83(7): 1739-1752, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33843756

RESUMEN

An exceedingly facile green approach that produces a reliable adsorbent based on a transition metal such as Iron (Fe) using Mangifera indica leaf extract at room temperature is described. A single pot method was used for synthesis with no capping agents, surfactants or other templates. The main intention of this study is to synthesize iron nanoparticles from leaf extract (Mangifera indica) and examine its degradation potential for photo-catalytic removal of dyes (Congo red and brilliant green) from wastewater. Characterization of synthesized nanoparticles was executed by pHpzc, scanning electron microscopy and Fourier transform infrared spectroscopy studies and results confirm the presence of iron nano-sheets with biomolecules. All photo-catalytic experimental results were assessed by sum of squared estimate of errors and simple linear regression R2 with dye concentration, pH, contact time and dose rate as dependent and independent variables. Adsorption experimental data was verified by kinetics and isothermal models. Results showed that Langmuir and pseudo second order models give best fitness towards the photo-catalytic adsorption procedure. Thermodynamics revealed that adsorption mechanism is endothermic, described by the values of changes in Gibbs free energy, enthalpy and entropy, and is chemisorption in nature, with spontaneous processes. Overall photo-catalytic adsorption execution with synthesized iron nanoparticles and simple biomass of Mangifera indica gives satisfactory results for treating dye wastewater.


Asunto(s)
Nanopartículas , Contaminantes Químicos del Agua , Adsorción , Colorantes , Concentración de Iones de Hidrógeno , Cinética , Mangifera , Extractos Vegetales , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica
7.
Bioresour Technol ; 132: 446-52, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23433975

RESUMEN

The sorption of Pb(II) and Cu(II) form aqueous media by Rosa bourbonia waste phyto-biomass (RBWPB) pretreated with organic acids was investigated as a function of biosorbent dosage, initial metal ions concentration and contact time. The equilibrium biosorption data was analyzed using two kinetic models (pseudo-first order and pseudo-second order) and two isotherm models (Langmuir and Freundlich). The RBWPB was successfully applied for sequestration of both heavy metal ions; however, organic acids pretreatments decreased the metal adsorption capacity of RBWPB. The Langmuir model fitted well to the data, and the pseudo-second order kinetic equation could best describe the biosorption kinetics of Pb(II) and Cu(II) metal ions. Gibbs free energy indicated the spontaneous adsorption of Pb(II) and Cu(II) onto RBWPB.


Asunto(s)
Ácidos Carboxílicos/metabolismo , Cobre/metabolismo , Flores/metabolismo , Plomo/metabolismo , Rosa/metabolismo , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Ácido Acético , Adsorción/efectos de los fármacos , Ácido Benzoico , Biodegradación Ambiental , Ácidos Carboxílicos/farmacología , Ácido Cítrico , Flores/efectos de los fármacos , Cinética , Modelos Biológicos , Análisis de Regresión
8.
Environ Monit Assess ; 184(4): 1909-19, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21887481

RESUMEN

Environmental impact assessment (EIA) is a policy tool used for evaluating a project proposal from physical and socioeconomic environmental perspectives. Its aim is to reduce the impact of development on environment, hence, ensuring environmental sustainability. It is mandatory to submit an Environmental Impact Statement before starting a mega project as required by Environmental Protection Act of 1997 and Environmental Policy of Pakistan. Public consultation plays a key role in an EIA system, identifying the likely aspects and impacts of a development activity. This aspect has been ignored in effective enactment of environmental legislation in Pakistan. Sufficient legislative instruments are there to support EIA system in the country but the agencies responsible for the enforcement of environmental regulations have failed to do so. The current research gives an insight into the actual status of EIA system in Pakistan along with the feedback of EIA specialists and university teachers of the concerned departments. A new index has been devised on the basis of questionnaire response to work out the overall performance of EIA system in Pakistan or any other country. The weaknesses and deficiencies of each EIA stage have been worked out for Pakistan and elaborated with the help of the controversial Zero point Interchange Project in the capital city of Pakistan.


Asunto(s)
Conservación de los Recursos Naturales , Monitoreo del Ambiente/métodos , Contaminación Ambiental/prevención & control , Formulación de Políticas , Pakistán , Política Pública
9.
Biotechnol Res Int ; 2011: 685023, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21350666

RESUMEN

Rosa centifolia and Rosa gruss an teplitz distillation waste biomass was immobilized using sodium alginate for Pb(II) uptake from aqueous solutions under varied experimental conditions. The maximum Pb(II) adsorption occurred at pH 5. Immobilized rose waste biomasses were modified physically and chemically to enhance Pb(II) removal. The Langmuir sorption isotherm and pseudo-second-order kinetic models fitted well to the adsorption data of Pb(II) by immobilized Rosa centifolia and Rosa gruss an teplitz. The adsorbed metal is recovered by treating immobilized biomass with different chemical reagents (H(2)SO(4), HCl and H(3)PO(4)) and maximum Pb(II) recovered when treated with sulphuric acid (95.67%). The presence of cometals Na, Ca(II), Al(III), Cr(III), Cr(VI), and Cu(II), reduced Pb(II) adsorption on Rosa centifolia and Rosa gruss an teplitz waste biomass. It can be concluded from the results of the present study that rose waste can be effectively used for the uptake of Pb(II) from aqueous streams.

10.
J Hazard Mater ; 168(2-3): 1622-5, 2009 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-19394142

RESUMEN

Biosorption of Cu(II) ions onto blackgram bran (BGB) waste biomass in a well stirred batch system was investigated and optimum conditions were determined. The maximum Cu(II) uptake capacity of BGB was 107.65 mg L(-1) at pH 5, biosorbent dose 0.025 g/100mL, biosorbent particle size <0.250 mm at an initial metal concentration of 50 mg L(-1) achieved after equilibrium time of 480 min. The equilibrium data fitted very well to Langmuir isotherm model as compared to the isothermal model of Freundlich. The pseudo 1st and 2nd order kinetic models were used to describe the kinetic data. The experimental data fitted well to 2nd order kinetic model. Due to its outstanding Cu(II) ions uptake capacity, BGB biomass proved to be an excellent material of bioorigin for accumulating Cu(II) ions from aqueous solutions.


Asunto(s)
Biomasa , Cobre/química , Contaminantes Químicos del Agua/química , Concentración de Iones de Hidrógeno , Cinética , Tamaño de la Partícula
11.
J Hazard Mater ; 161(1): 88-94, 2009 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-18502037

RESUMEN

Studies on the biosorptive ability of Gossypium hirsutum (Cotton) waste biomass outlined that smaller size of biosorbent (0.355mm), higher biomass dose (0.20g), 5 pH and 100mg/L initial Pb(II) concentration were more suitable for enhanced Pb(II) biosorption from aqueous medium. The Langmuir isotherm model and pseudo second order kinetic model fitted well to the data of Pb(II) biosorption. Highly negative magnitude of Gibbs free energy (DeltaG degrees ) indicated that the process was spontaneous in nature. In addition to this surface coverage and distribution coefficient values of Pb(II) biosorption process were also determined. At optimized conditions Pb(II) uptake was more rapid in case of industrial effluents in comparison to synthetic solutions. FTIR spectroscopic analysis revealed that the main functional groups involved in the uptake of Pb(II) on the surface of G. hirsutum biomass were carboxyl, carbonyl, amino and alcoholic.


Asunto(s)
Biomasa , Fibra de Algodón/métodos , Sustancias Peligrosas/análisis , Sustancias Peligrosas/metabolismo , Plomo/análisis , Plomo/metabolismo , Contaminantes Químicos del Agua/análisis , Concentración de Iones de Hidrógeno , Cinética , Semillas/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Contaminantes Químicos del Agua/metabolismo
12.
J Hazard Mater ; 156(1-3): 64-73, 2008 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-18242826

RESUMEN

The present study reports the use of locally available fish (Labeo rohita) scales for Pb(II) removal from aqueous solutions under different experimental conditions. Maximum Pb(II) adsorption (196.8 mg g(-1)) occurred at pH 3.5. Pb(II) sorption was found to be pH, dose, initial metal concentration, contact time and shaking speed dependent while particle size and temperature independent. Experimental data of Pb(II) biosorption onto fish scales fitted well to Freundlich isotherm model in comparison to the model of Langmuir. The fast adsorption process in first 30 min followed by subsequent slow adsorption rate was suitably described by pseudo-second order model. In addition, this study was designed to evaluate the effect of physical and chemical pretreatments on surface properties of fish scales by the application of Fourier Transform Infrared (FTIR) Spectroscopic analysis. Physical pretreatments resulted in partial degradation of some functional groups. Alkaline pretreatments of fish scales did not have any significant influence on the nature of functional groups responsible for Pb(II) uptake, while acidic pretreatments resulted in degeneration of the most of functional groups on biosorbent cell wall. FTIR analysis confirmed the involvement of amino, carboxylic, phosphate and carbonyl groups in Pb(II) biosorption by fish scales.


Asunto(s)
Peces/metabolismo , Plomo/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Animales , Plomo/química
13.
J Hazard Mater ; 157(2-3): 534-40, 2008 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-18289783

RESUMEN

An adsorbent was developed from mature leaves and stem bark of the Neem (Azadirachta indica) tree for removing zinc from water. Adsorption was carried out in a batch process with several different concentrations of zinc by varying pH. The uptake of metal was very fast initially, but gradually slowed down indicating penetration into the interior of the adsorbent particles. The data showed that optimum pH for efficient biosorption of zinc by Neem leaves and stem bark was 4 and 5, respectively. The maximum adsorption capacity showed that the Neem biomass had a mass capacity for zinc (147.08 mg Zn/g for Neem leaves and 137.67 mg Zn/g Neem bark). The experimental results were analyzed in terms of Langmuir and Freundlich isotherms. The adsorption followed pseudo-second-order kinetic model. The thermodynamic assessment of the metal ion-Neem tree biomass system indicated the feasibility and spontaneous nature of the process and DeltaG degrees values were evaluated as ranging from -26.84 to -32.75 (Neem leaves) kJ/mol and -26.04 to -29.50 (Neem bark) kJ/mol for zinc biosorption. Due to its outstanding zinc uptake capacity, the Neem tree was proved to be an excellent biomaterial for accumulating zinc from aqueous solutions.


Asunto(s)
Azadirachta/química , Biomasa , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Zinc/aislamiento & purificación , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Hojas de la Planta/química , Soluciones/química , Espectrofotometría Atómica , Contaminantes Químicos del Agua/química , Zinc/química
14.
J Hazard Mater ; 150(2): 335-42, 2008 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-17543452

RESUMEN

The waste distillery sludge from sugar-cane industry was pretreated physically (boiled, heated and autoclaved) as well as chemically (HCl, H(2)SO(4), H(3)PO(4), NaOH, Ca(OH)(2), Al(OH)(3), C(6)H(6), HCHO, CH(3)OH and C1(2)H(25)OSO(3)Na (sodium dodecyl sulphate (SDS)) for assessing the comparative sorption capacity of untreated and modified distillery sludge for Pb(II) biosorption from aqueous solutions. Experiments were conducted in shake flasks on a batch basis to access the effect of different experimental parameters such as pH, biosorbent dosage, biosorbent size, initial Pb(II) concentration and contact time. The uptake capacity 'q' (mg/g) of untreated and pretreated distillery sludge was in following order: NaOH (51.29+/-1.21)>HCl (49.82+/-1.22)>HCHO (49.56+/-1.14)>H(2)SO(4) (47.71+/-1.20)>HgCl(2) (45.32+/-1.06)>Ca(OH)(2) (44.01+/-1.18)>MeOH (43.73+/-1.23)>C(6)H(6) (42.72+/-1.19)>H(3)PO(4) (42.01+/-1.17)>SDS (40.87+/-1.27)>autoclaved (40.23+/-1.24)>Boiled (39.95+/-1.19)>heated (38.87+/-1.32)>Al (OH)(3) (38.30+/-1.14)>untreated (37.76+/-1.21). In further parameter studies, the optimized biosorbent size was 0.250 mm at pH 5 and best dose was 0.05 g of biosorbent. The applicability of the Langmuir and Freundlich models for sorption process was tested and best fitted model was Langmuir with the coefficient of determination (R(2)) value, 0.97, the process followed second order kinetic mechanism.


Asunto(s)
Plomo/aislamiento & purificación , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Absorción , Concentración de Iones de Hidrógeno , Residuos Industriales , Cinética , Termodinámica
15.
J Hazard Mater ; 147(3): 1006-14, 2007 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-17363153

RESUMEN

Removal of lead(II) and zinc(II) from aqueous solutions was studied using chemically modified distillation sludge of rose (Rosa centifolia) petals by pretreatment with NaOH, Ca(OH)(2), Al(OH)(3), C(6)H(6), C(6)H(5)CHO and HgCl(2). The adsorption capacity of biomass was found to be significantly improved. NaOH pretreated biomass showed remarkable increase in sorption capacity. Maximum adsorption of both metal ions was observed at pH 5. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The overall adsorption process was best described by pseudo second order kinetics. The thermodynamic assessment of the metal ion-Rosa centifolia biomass system indicated the feasibility and spontaneous nature of the process and DeltaG degrees was evaluated as ranging from -26.9501 to -31.652 KJmol(-1) and -24.1905 to -29.8923KJmol(-1) for lead(II) and zinc(II) sorption, respectively, in the concentration range 10-640mgL(-1). Distribution coefficient (D) showed that the concentration of metal ions at the sorbent-water interface is higher than the concentration in the continuous aqueous phase. Maximum adsorption capacity of biomass tends to be in the order Pb(II) (87.74mgg(-1))>Zn(II) (73.8mgg(-1)) by NaOH pretreated biomass.


Asunto(s)
Plomo/aislamiento & purificación , Rosa/química , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/aislamiento & purificación , Zinc/aislamiento & purificación , Absorción , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica
16.
J Hazard Mater ; 145(3): 501-5, 2007 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-17289258

RESUMEN

The present study explores the ability of Cassia fistula waste biomass to remove Ni(II) from industrial effluents. C. fistula biomass was found very effective for Ni(II) removal from wastewater of Ghee Industry (GI), Nickel Chrome Plating Industry (Ni-Cr PI), Battery Manufacturing Industry (BMI), Tanner Industry: Lower Heat Unit (TILHU), Tannery Industry: Higher Heat Unit (TIHHU), Textile Industry: Dying Unit (TIDU) and Textile Industry: Finishing Unit (TIFU). The initial Ni(II) concentration in industrial effluents was found to be 34.89+/-0.01, 183.56+/-0.08, 21.19+/-0.01, 43.29+/-0.03, 47.26+/-0.02, 31.38+/-0.01 and 31.09+/-0.01mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. After biosorption the final Ni(II) concentration in industrial effluents was found to be 0.05+/-0.01, 17.26+/-0.08, 0.03+/-0.01, 0.05+/-0.01, 0.1+/-0.01, 0.07+/-0.01 and 0.06+/-0.01mg/L in GI, Ni-Cr PI, BMI, TILHU, TIHHU, TIDU and TIFU, respectively. The % sorption Ni(II) ability of C. fistula from seven industries included in present study tend to be in following order: TILHU (99.88)>GI (99.85) approximately BMI (99.85)>TIFU (99.80)>TIHHU (99.78)>TIDU (99.77)>>Ni-Cr PI (90.59). Sorption kinetic experiments were performed in order to investigate proper sorption time for Ni(II) removal from wastewater. Batch metal ion uptake capacity experiments indicated that sorption equilibrium reached much faster in case of industrial wastewater samples (480min) in comparison to synthetic wastewater (1440min) using same biosorbent. The kinetic data were analyzed in term of pseudo-first-order and pseudo-second-order expressions. Pseudo-second-order model described well the sorption kinetics of Ni(II) onto C. fistula biomass from industrial effluents in comparison to pseudo-first-order kinetic model. Due to unique high Ni(II) sorption capacity of C. fistula waste biomass it can be concluded that it is an excellent biosorbent for Ni(II) uptake from industrial effluents.


Asunto(s)
Cassia/metabolismo , Contaminantes Ambientales/aislamiento & purificación , Níquel/aislamiento & purificación , Adsorción , Biodegradación Ambiental , Biomasa , Contaminantes Ambientales/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Níquel/metabolismo , Tamaño de la Partícula , Espectrofotometría Atómica
17.
J Hazard Mater ; 139(2): 345-55, 2007 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-16860463

RESUMEN

Cassia fistula is a fast-growing, medium-sized, deciduous tree which is now widely cultivated worldwide as an ornamental tree for its beautiful showy yellow flowers. Methods are required to reuse fallen leaves, branches, stem bark and pods when they start getting all over lawn. This investigation studies the use of these non-useful parts of C. fistula as naturally occurring biosorbent for the batch removal of Ni(II) in a well stirred system under different experimental conditions. The data showed that the maximum pH (pHmax) for efficient sorption of Ni(II) was 6 at which evaluated biosorbent dosage, biosorbent particle size, initial concentrations of Ni(II) and sorption time were 0.1 g/100 mL, <0.255 mm, up to 200 mg/L and 720 min, respectively. The experimental results were analyzed in terms of Langmuir and Freundlich isotherms. The Langmuir isotherm model fitted well to data of Ni(II) biosorption by C. fistula biomass as compared to the model of Freundlich. The kinetic studies showed that the sorption rates could be described better by a second order expression than by a more commonly applied Lagergren equation. The magnitude of the Gibbs free energy values indicates spontaneous nature of the sorption process. The sorption ability of C. fistula biomass for Ni(II) removal tends to be in the order: leaves

Asunto(s)
Cassia/metabolismo , Contaminantes Ambientales/aislamiento & purificación , Níquel/aislamiento & purificación , Adsorción , Contaminantes Ambientales/metabolismo , Concentración de Iones de Hidrógeno , Cinética , Níquel/metabolismo , Tamaño de la Partícula , Corteza de la Planta/metabolismo , Hojas de la Planta/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier
18.
J Hazard Mater ; 143(1-2): 478-85, 2007 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-17049420

RESUMEN

In the present study biosorption technique, the accumulation of metals by biomass was used for the removal of nickel from aqueous medium. The rice bran in its acid treated (H(3)PO(4)) form was used as a low cost sorbent. The adsorption characteristics of nickel on protonated rice bran were evaluated as a function of pH, biosorbent size, biosorbent dosage, initial concentration of nickel and time. Within the tested pH range (pH 1-7), the protonated rice bran displayed more resistance to pH variation, retaining up to 102 mg/g of the nickel binding capacity at pH 6. Meanwhile, at lower pH values the uptake capacity decreased. The % age removal of nickel was maximum at 0.25 g of biosorbent dose and 0.25 mm biosorbent size. At the optimal conditions, metal ion uptake was increased as the initial metal ion concentration increased up to 100mg/L. Kinetic and isotherm experiments were carried out at the optimal pH 6.0 for nickel. The metal removal rate was rapid, with 57% of the total adsorption taking place within 15-30 min. The Freundlich and Langmuir models were used to describe the uptake of nickel on protonated rice bran. The Langmuir and Freundlich model parameters were evaluated. The equilibrium adsorption data was better fitted to Langmuir adsorption isotherm model. The adsorption followed pseudo second-order kinetic model. The thermodynamic assessment of the metal ion-rice bran biomass system indicated the feasibility and spontaneous nature of the process and DeltaG degrees values were evaluated as ranging from -22.82 to -24.04 kJ/mol for nickel sorption. The order of magnitude of the DeltaG degrees values indicated an ion-exchange physiochemical sorption process.


Asunto(s)
Níquel/química , Oryza/química , Adsorción , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Modelos Químicos , Termodinámica , Factores de Tiempo
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