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1.
J Fluoresc ; 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37646872

RESUMEN

Anthraquinones constitute an important class of compounds with wide applications. The solubility of derivatives at 298.15 K was discussed in ethanol-water solution and at atmospheric pressure, the solubility of 1-amino-4-hydroxy-9,10-anthraquinone (AHAQ) in binary solvents (ethanol-water combinations) was determined. Colour strength and fastening properties depend upon the kind and position of a hydrophobic group connected to the phenoxy ring of Anthraquinone moiety. There is a continuing interest in the creation of novel anthraquinone derivatives with biological activities since they have demonstrated potential for treating multiple sclerosis. For this purpose, by utilizing voltammetric and absorption studies, interactions of various derivatives with calf thymus DNA (ct-DNA) and the cationic surfactant cetyltrimethylammoniumbromide (CTAB) were examined. Here prominent Hydrophobic interaction and electron transfer resulting in binding to CTAB micelles were observed. The polarity index of the media was assessed and associated with the electrochemical parameters. The medicinal behaviour of Anthraquinone derivatives was a result of electron transfer reactions with DNA. UV-Visible and fluorescence properties were due to the transitions between n* and π* orbitals. Large absorption band with low dichroic ratio was characteristic of various derivatives of Anthraquinone. Presence of -NH group proves various derivatives remarkable calorimetric and anionic sensors.

2.
Pak J Pharm Sci ; 32(6(Supplementary)): 2893-2898, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32024630

RESUMEN

Hypertension is persistent elevation in blood pressure for 3-4 weeks. Estimated global prevalence of hypertension suggested that by the Year 2025 (29%) of adult worldwide are suffering from hypertension (1.56 billion). Hypertension complications are hemorrhage, atherosclerosis, renal artery stenosis, angina pectoris end organ damage, cardiomyopathy, myocardial infarction and retinopathy. Along with other drug class Calcium channel blocker are also used for the treatment of hypertension. In this study the possible action of the n-hexane leaves fraction of the Androsace foliosa on isolated rabbit aorta was examined. Antihypertensive activity was examined in the existence of standard agonist like phenylephrine and antagonist like Verapamil. Phenylephrine (PE 1µM) high K+ was used to steady the tissue materials. Additionally to observe the calcium channel blocking effect the tissues were treated with n-hexane segment of A. foliosa leaves. Aortic tissues were treated 4-5intervals with Ca+2- free preparation earlier to control calcium reaction curve (CRCs). Verapamil is utilized as standard calcium channel inhibitory mediator and is used as an antagonist. The Af. n-hexane leaves fraction completely inhibited the precontractions induced by Phenylephrine (1µM) and K+ (80 mM) precontractions, with EC50 standards of 1.0mM (0.3-1.0mg/mL) and 4.90mM (1-3mg/mL), respectively. Androsace foliosa n-hexane leaves fraction was tested for calcium channel inhibitory effect on isolated rabbit aorta. A. foliosa n- hexane leaves segment at the dosage of 1mg/mL block the calcium channel approximately (35±5%). Consequence indicates that A. foliosa n-hexane leaves segment block calcium channel in the similar manner as compared to the standard calcium channel blocker drug (verapamil).


Asunto(s)
Antihipertensivos/farmacología , Aorta Torácica/efectos de los fármacos , Bloqueadores de los Canales de Calcio/farmacología , Hipertensión/tratamiento farmacológico , Extractos Vegetales/farmacología , Primulaceae/química , Animales , Antihipertensivos/aislamiento & purificación , Aorta Torácica/metabolismo , Aorta Torácica/fisiopatología , Presión Sanguínea/efectos de los fármacos , Bloqueadores de los Canales de Calcio/aislamiento & purificación , Canales de Calcio/metabolismo , Femenino , Hexanos/química , Técnicas In Vitro , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta/química , Conejos , Vasodilatación/efectos de los fármacos
3.
Water Sci Technol ; 76(5-6): 1035-1043, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28876245

RESUMEN

Batch and column adsorption modes were compared for the adsorption of U(VI) ions using rice husk waste biomass (RHWB). Response surface methodology was employed for the optimization of process variables, i.e., (pH (A), adsorbent dose (B), initial ion concentration (C)) in batch mode. The B, C and C2 affected the U(VI) adsorption significantly in batch mode. The developed quadratic model was found to be validated on the basis of regression coefficient as well as analysis of variance. The predicted and actual values were found to be correlated well, with negligible residual value, and B, C and C2 were significant terms. The column study was performed considering bed height, flow rate and initial metal ion concentration, and adsorption efficiency was evaluated through breakthrough curves and bed depth service time and Thomas models. Adsorption was found to be dependent on bed height and initial U(VI) ion concentration, and flow rate decreased the adsorption capacity. Thomas models fitted well to the U(VI) adsorption onto RHWB. Results revealed that RHWB has potential to remove U(VI) ions and batch adsorption was found to be efficient versus column mode.


Asunto(s)
Oryza , Uranio/química , Contaminantes Radiactivos del Agua/química , Purificación del Agua/métodos , Adsorción , Biomasa , Concentración de Iones de Hidrógeno , Residuos Radiactivos
4.
Nanoscale Adv ; 6(18): 4693-4703, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39263407

RESUMEN

Aflatoxin M1 (AFM1), a hydroxylated metabolite of aflatoxin B1 (AFB1), contaminates milk and dairy products from livestock via ingestion of feed contaminated with a species of Aspergillus. As AFM1 is a Group-II B carcinogen, it is indispensable to develop novel, easy-to-handle, sensitive, portable and cost-effective strategies for its detection. Herein, a covalent organic framework (COF)-based electroactive nanocomposite, Ag2O/g-C3N4-COOH@MA-DBB-COF (silver oxide/carboxy-functionalized graphitic carbon nitride@melamine-dibromo butane COF), is designed to serve as a multifunctional receptor surface. The Ag2O/g-C3N4-COOH@MA-DBB-COF formation was characterized through X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, micro-Raman spectroscopy (RAMAN), dynamic light scattering (DLS) and thermogravimetric analysis (TGA), and each step of the sensor fabrication was monitored using field emission scanning electron microscopy (FE-SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the designed immunosensor permitted the detection of AFM1 in the linear range of 0.03-1000 fg mL-1, with a 0.01 fg mL-1 limit of detection (LOD). The selectivity of the designed immunosensor was validated via an anti-interference study. The practical applicability of the immunosensor was demonstrated by the detection of AFM1 in real milk samples, and good recovery values (97.28-102.62%) were obtained. Furthermore, the developed immunosensor and high-performance liquid chromatography (HPLC) were employed in parallel to detect AFM1 in local market milk samples from twenty different sites to validate the performance of the newly designed immunosensor. Additionally, the designed immunosensor was stable over an extended period of time. This work reports a single-step field-portable multifunctional innovative electrochemical immunoreceptor design for on-site and label-free detection of AFM1 in milk samples. Hence, the present study is the first report on the fabrication of a multifunctional innovative electrochemical immunoreceptor based on PGE/Ag2O/g-C3N4-COOH@MA-DBB-COF for the detection of AFM1 in milk samples.

5.
Plant Physiol Biochem ; 195: 341-350, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36681064

RESUMEN

Drought is one of the major abiotic stresses which negatively affects plant growth and development. The current study evaluated the effects of drought on the growth, physiology, and biochemical attributes of wheat seedlings; and examined the role of foliar application of ZnO nanoparticles in alleviating drought-induced effects. Two wheat cultivars i.e., Anaj-2017 and FSD-2018 were grown in soil-filled pots and were subjected to 100% field capacity (FC) (well watered) and 50% of FC (drought stress). Whilst different treatments of ZnO nanoparticles spray included no spray, water spray, and 50, 100, and 150 ppm ZnO. Results demonstrated that drought caused a significant reduction in seedling fresh and dry weights, photosynthetic pigmentation, and antioxidant activities compared with a well-watered treatment. Nevertheless, the application of 100 and 150 ppm of ZnO nanoparticles effectively ameliorated the negative effects of drought and enhanced the performance of both cultivars under drought. Data revealed a significant increase in fresh and dry weight of shoot and root with the application of ZnO nanoparticles. A substantial increase of 73.68% and 28.51% in chlorophyll "a" and 26.15% and 50.02% in chlorophyll "b" was recorded with the application of 100 ppm of ZnO nanoparticles in Anaj-2017 and FSD-2018, respectively over control (0 ppm). The application of these nanoparticles also triggered the antioxidant defense system and protected the crop from oxidative damage. Averaged across different stress treatments, application of 150 and 100 ppm of ZnO nanoparticles increased the peroxidase activity by 60% and 72% in FSD-2018, and 15% and 23% in Anaj-2017, respectively compared with no spray. FSD-2018 outperformed Anaj-2017 regarding its overall performance under ZnO treatments and drought conditions. In a nutshell, it can be concluded that ZnO nanoparticles ameliorated the negative impacts of drought by improving the growth, physiology, and antioxidant defense of both wheat cultivars.


Asunto(s)
Óxido de Zinc , Óxido de Zinc/farmacología , Plantones , Sequías , Triticum/fisiología , Antioxidantes/farmacología , Clorofila , Agua/farmacología , Clorofila A
6.
ACS Omega ; 8(10): 9539-9546, 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36936294

RESUMEN

The study focused on the fabrication of nickel, cobalt, and their bimetallic oxide via a facile electrodeposition approach over the surface of conducting glass has been reported here. Fabricated electrodes have been employed as binder-free and effective anode materials toward oxygen evolution reactions (OER) in electrochemical water splitting at high pH. Nickel and cobalt oxides showed overpotential values of 520 mV and 536 mV at the current density of 10 mAcm-2 with charge transfer resistances of 170 and 195 Ω. For bimetallic oxides (NiCoO@FTO), the overpotential depressed up to 460 mV and lower charge transfer value of 80 Ω. Additionally, double-layer capacitance also boosted for the bimetallic oxide with a value of 199 µF as compared to monometallic nickel oxide (106 µF) and cobalt oxide (120 µF). Multimetal oxides of Ni-Co showed the best performance, which was further supported with larger electrochemical surface area. This facile approach toward the electrode fabrication could be a charming alternate to replace the Ru- and Ir-based expensive materials for OER in electrochemical water splitting.

7.
Plant Signal Behav ; 18(1): 2186045, 2023 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-37016728

RESUMEN

Drought stress poorly impacts many morphological and physio-biochemical processes in plants. Pea (Pisum sativum L.) plants are highly nutritious crops destined for human consumption; however, their productivity is threatened under drought stress. Thiamine (vitamin B1) is well-known essential micronutrient, acting as a cofactor in key metabolic processes. Therefore, this study was designed to examine the protective effect of foliar application of thiamine (0, 250, and 500 ppm) on two varieties of pea plants under drought stress. Here, we conducted the pot experiment at the Government College Women University, Faisalabad, to investigate the physio-biochemical and morphological traits of two pea varieties (sarsabz and metior) grown under drought stress and thiamine treatment. Drought stress was applied to plants after germination period of 1 month. Results showed that root fresh and dry weight, shoot fresh and dry weight, number of pods, leaf area, total soluble sugars, total phenolics, total protein contents, catalase, peroxidase, and mineral ions were reduced against drought stress. However, the application of thiamine (both 250 and 500 ppm) overcome the stress and also enhances these parameters, and significantly increases the antioxidant activities (catalase and peroxidase). Moreover, the performance of sarsabz was better under control and drought stress conditions than metior variety. In conclusion, the exogenous application of thiamine enabled the plants to withstand drought stress conditions by regulating several physiological and biochemical mechanisms. In agriculture, it is a great latent to alleviate the antagonistic impact of drought stress on crops through the foliar application of thiamine.


Asunto(s)
Pisum sativum , Tiamina , Femenino , Humanos , Catalasa/metabolismo , Tiamina/farmacología , Tiamina/metabolismo , Pisum sativum/fisiología , Sequías , Antioxidantes/metabolismo , Peroxidasa/metabolismo
8.
Int J Biol Macromol ; 224: 1337-1355, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36309237

RESUMEN

Dyes are emerging as harmful pollutants, which is one of major issues for the environmentalists and there is a urgent need for the removal of dyes from the effluents. In this context, the adsorption technology has been extensively used as an effective tool for the removal of dyes from the aqueous phase. This technique uses low-cost adsorbents and the cellulosic material is a biodegradable, cost-effective and renewable polymer, which is not soluble in the majority of solvents because of its crystalline nature and hydrogen bonding. Currently, the modified cellulosic materials for the removal of dyes from wastewater gained much attention. Moreover, the application of cellulose for water treatment can be utilized for controlling pollution and have high economic viability and availability. This review signifies the use of cellulose-based adsorbent for dyes adsorption from wastewater. The key advancement in the preparation and modification of cellulose-based adsorbents is discussed and their adsorption efficiencies are compared with other adsorbents for removal of dyes and adsorption conditions are also considered for the same. The studies reporting cellulose-based adsorption from 2003 to 2022 are included and their various properties are compared for the efficient removal of dyes. The modified cellulosic materials cellulose is a highly effective adsorbent for the remediation of effluents.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Colorantes/química , Aguas Residuales , Contaminantes Químicos del Agua/química , Adsorción , Celulosa/química , Purificación del Agua/métodos
9.
Int J Biol Macromol ; 209(Pt A): 576-585, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35405153

RESUMEN

Cellulose/clay/sodium alginate composites were prepared and employed for the removal of methylene blue (MB) dye. Cellulose was extracted from a paper mill waste and used for composite preparation with sodium alginate (Na-Alg) and clay. MB dye removal was analyzed at different operating conditions (pH, initial concentration, temperature, composite dose). The dye was adsorbed up to 90% for an equilibrium time of 60 min at optimum level of adsorbent dose (0.05 g), temperature (30 °C) and pH (i.e., 7 and 11 for cellulose-Na-Alg and cellulose-Na-Alg-clay, respectively). Kinetics and isotherms of MB adsorption were quantified and modeled. Results showed that MB dye adsorption data followed the pseudo-first order kinetics and a statistical physics model was used to analyze the adsorption mechanism. Thermodynamic calculation revealed that the MB dye adsorption on these composites was an exothermic, spontaneous and feasible process. The composites were regenerated with HCl thus contributing to their reutilization in subsequent adsorption cycles. The DFT (density functional theory) calculations were executed to explain the interactions responsible for the adsorption of MB dye on the composites. Results revealed that the Na-Alg-cellulose composites were effective for the MB dye removal. Therefore, these composites can be considered as low-cost alternative adsorbents for the pollution remediation caused by dyes in industrial effluents.


Asunto(s)
Azul de Metileno , Contaminantes Químicos del Agua , Adsorción , Alginatos , Celulosa , Arcilla , Colorantes , Concentración de Iones de Hidrógeno , Cinética
10.
Int J Biol Macromol ; 161: 1272-1285, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32502609

RESUMEN

Clay-based composites were prepared, characterized, and applied for the elimination of Blue FBN (BFBN) and Rose FRN (RFRN) dyes. The Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), Thermogravimetric (TGA) and X-ray diffraction analyses were performed to check the interaction of dye molecule with adsorbents. The analysis showed a successful interaction between adsorbent and dyes ions. The experimental data was best fitted with Freundlich isotherm for both dyes (BFBN and RFRN). The findings revealed that at 80 min the adsorption grasped equilibrium in the case of both dyes and succeeded the pseudo-second-order kinetics model. Furthermore, the enthalpy (ΔH°), Gibbs free energy (ΔG°) and entropy (ΔS°) changes suggested that adsorption was exothermic, physical and spontaneous in nature. The maximum adsorption capacities were determined as 76.39% for BFBN and 59.85% for RFRN dye at pH 2.0 and 30 °C. Composites found to be stable at higher temperature and regenerated using MgSO4 eluting agent. The textile effluent colour was removed up to 50.35 and 54.95% using raw and modified clay, respectively. The modified clay showed promising efficiency for adsorption of synthetic BFBN and RFRN dyes from aqueous solution, which could be a viable option for the treatment of industrial wastewater and textile effluents.


Asunto(s)
Alginatos/química , Materiales Biocompatibles/química , Arcilla/química , Aguas Residuales/química , Purificación del Agua , Adsorción , Colorantes/química , Concentración de Iones de Hidrógeno , Cinética , Modelos Químicos , Fenómenos Físicos , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Termodinámica , Termogravimetría , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Difracción de Rayos X
11.
Int J Biol Macromol ; 147: 217-232, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31923499

RESUMEN

In view of promising adsorption efficiency of biocomposites, the removal of imidacloprid was studied using biocomposites of polypyrole (PPY), polyaniline (PAN) and sodium alginate (Na-Alginate) with peanut husk (PH). The affecting variables such as pH, insecticide concentration, composite dose, contact time, temperature were optimized for efficient removal of imidacloprid. The biocomposites showed promising efficiency for the removal of imidacloprid. Among all composites polypyrole composite exhibited maximum efficiency at pH 3, 0.05 g adsorbent dose, 90 min contact time, 25 mg/L initial concentration at 35 °C. Langmuir, Freundlich, Harkins-Jura and Temkin isotherms models were applied on the experimental data. The best fitted were Langmuir and Freundlich isotherms with R2 value > 0.904 and >0.97, respectively. Insecticide adsorption followed the pseudo first order kinetics model. Thermodynamics (free energy, enthalpy and entropy) study revealed that the insecticide adsorption process on to biocomposites was spontaneous and exothermic in nature. This study revealed that the polypyrole, polyaniline and sodium alginate composites with peanut husk have promising adsorption potential and this class of adsorbent could be used for the remediation of wastewater contains imidacloprid insecticide.


Asunto(s)
Alginatos/química , Compuestos de Anilina/química , Materiales Biocompatibles/química , Insecticidas/química , Neonicotinoides/química , Nitrocompuestos/química , Polímeros/química , Pirroles/química , Adsorción , Biomasa , Concentración de Iones de Hidrógeno , Iones , Cinética , Metales/química , Modelos Químicos , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo
12.
Int J Biol Macromol ; 149: 1059-1071, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32027903

RESUMEN

Cellulose/clay composites were prepared and applied for the adsorption of Drimarine Yellow HF-3GL direct dye. The prepared composites were characterized by FTIR, TGA, EDX, SEM and XRD techniques. Bagasse was used as a cellulose source, while clay was obtained from local source, which was modified chemically before composite preparation. Adsorption efficiencies were compared of composite I and II as a function of contact time, temperature, pH, initial dye concentration and composite dose. Non-linear kinetic and equilibrium isotherm employed and dye adsorption data fitted well to pseudo-second order kinetics model. Among isotherms, the Redlich-Peterson isotherm well defined the sorption process of dye on to composites. Thermodynamic factors (ΔS°, ΔH° and ΔG°) revealed that the sorption process was spontaneous, exothermic and feasible. Cellulose/clay composite I and II removed 88.64% and 89.95% dye with 60 min at pH 2 and 30 °C, respectively. For reusability, desorption was performed using different eluting agents and NaOH showed higher desorption efficiency. For the treatment of wastewater, the developed composites were applied to textile effluents and color removal of (90-96.07%) and (97-98.23%) was achieved using cellulose/clay composite I and II, respectively. The results showed that cellulose/clay composite are efficient for the removal dyes and could possibly be used for the treatment of textile effluents.


Asunto(s)
Celulosa/química , Arcilla/química , Colorantes/aislamiento & purificación , Compuestos Inorgánicos/química , Nanocompuestos/química , Compuestos Orgánicos/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Dinámicas no Lineales , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Textiles , Termogravimetría , Factores de Tiempo , Aguas Residuales/química
13.
Int J Biol Macromol ; 153: 146-157, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32114168

RESUMEN

The biocomposites of polypyrrole (PPY), polyaniline (PANI) and sodium alginate (NaAlg) with cellulosic biomass barley husk (BH) were prepared and employed for the removal of 2,4-dichlorophenol (2,4-DCP) form aqueous media. The sorption of 2,4-DCP was studied using native and biocomposites (PPY/BH, PANI/BH and NaAlg/BH) as function of various process variables. The maximum sorption (qe, 7.55-24.57 mg/g) of 2,4-DCP was achieved in the range of 7-10 pH, 0.05 g composite dose, 25 mg/L initial concentration of 2,4-DCP and 120 min contact time at 30 °C. The FTIR analysis revealed the involvement of amino, hydroxyl and carboxylic groups for the binding of 2,4-DCP on the surface of biocomposites. The Freundlich and pseudo second order kinetics models best explained the 2,4-DCP adsorption on to the biocomposites. The ∆G, ∆H and ∆S parameters were also computed, which revealed the favorable and exothermic adsorption nature of 2,4-DCP. Presence of salts affected the 2,4-DCP adsorption negatively. HCl found to be efficient desorbing agent for 2,4-DCP from composites and up to 65.12% was eluted using 0.5 N solution. In view of promising efficiency, the biocomposites have potential to remove 2,4-DCP form industrial effluents.


Asunto(s)
Alginatos/química , Compuestos de Anilina/química , Biomasa , Celulosa/química , Clorofenoles/aislamiento & purificación , Polímeros/química , Pirroles/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua , Clorofenoles/química , Contaminantes Químicos del Agua/química
14.
Dose Response ; 17(4): 1559325819889809, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31802995

RESUMEN

Soil salinity is one of the primary problem for agricultural crops which causes a great loss in crop production in Pakistan and worldwide. Various approaches have been implemented to overcome salinity problem. Assembly of crops for the enhancement of salt tolerance is a good strategy to achieve cost-effective yields. Cucumber is considered as one of the leading vegetable crop around the world for the nourishment of human being as source of nutrients, minerals, and vitamins. Screening of 12 cucumber genotypes using some physiological indices, that is, seedling germination stress tolerance index, plant height stress tolerance index, root length stress tolerance index, shoot and root dry weight stress tolerance index, and shoot and root fresh weight stress tolerance index were performed for the identification of salt tolerance. Using the above characteristics genotypes, Valley and HC-999 were categorized as tolerant, Safaa and Debra as medium tolerant, while Thamin-II identified as medium sensitive and NSC-CM1 and Akbar are classified as sensitive genotypes of cucumber. According to the current study findings, the screened cucumber genotypes for salinity tolerance can also be suggested to farmers for the improved production and yield of crop at saline soil.

15.
J Photochem Photobiol B ; 175: 282-290, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28923600

RESUMEN

Fungal biomass proves to be highly efficient for the treatment of wastewater as well as recovery of metal ions from wastewater. Present investigation was aimed to evaluate the efficiency of indigenous fungal isolates for the sequestration of Zn(II) ions aqueous solution. Among twenty five fungal isolates, Aspergillus oryzae SV/09 (AO SV/09), Aspergillus flavus NA9 (AF NA9) and Paecilomyces formosus DTO 63f4 (PF DTO-63f4) were identified by gene sequencing of ITS regions of the ribosomal DNA (rDNA). The AO SV/09, AF NA9 and PF DTO-63f4 showed promising efficiency for the biosorption of Zn(II) ions. Zn(II) ions adsorption was endothermic in nature and data fitted will to the Freundlich isotherm with correlation coefficients values of 0.99, 0.98 and 0.99 for AO SV/09, AF NA9 and PF DTO-63f4, respectively. Pseudo-second order kinetic model explained well the Zn(II) adsorption kinetic of Zn(II) ions onto biosorbents. The adsorbed Zn(II) ions were desorbed using HCl and 85.5, 75.3, 73.7 (%) Zn(II) ions were recovered from AO SV/09, AF NA9 and PF DTO-63f4 sorbents, respectively. The fungal biosorbents were successfully recycled up to five cycles. Based on sorption, recovery and regeneration, the application of fungal bio-sorbents for the sequestration and recovery of Zn(II) ions is suggested from wastewater and could possibly be extended for the recovery of other heavy metal ions from wastewater.


Asunto(s)
Aspergillus flavus/metabolismo , Aspergillus oryzae/metabolismo , Paecilomyces/metabolismo , Contaminantes Químicos del Agua/química , Zinc/química , Adsorción , Aspergillus flavus/genética , Aspergillus flavus/aislamiento & purificación , Aspergillus oryzae/genética , Aspergillus oryzae/aislamiento & purificación , Biomasa , ADN Ribosómico/química , ADN Ribosómico/genética , Concentración de Iones de Hidrógeno , Iones/química , Cinética , Paecilomyces/genética , Paecilomyces/aislamiento & purificación , Análisis de Secuencia de ADN , Temperatura , Termodinámica , Contaminantes Químicos del Agua/aislamiento & purificación , Zinc/aislamiento & purificación
16.
Chemosphere ; 169: 474-484, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27889513

RESUMEN

Citrus limon peroxidase mediated decolourization of Direct Yellow 4 (DY4) was investigated. The process variables (pH, temperature, incubation time, enzyme dose, H2O2 amount, dye concentration, co-metal ions and surfactants) were optimized for maximum degradation of dye. Maximum dye decolourization of 89.47% was achieved at pH 5.0, temperature 50 °C, enzyme dose 24 U/mL, H2O2 concentration 0.25 mM and DY4 concentration 18.75 mg/L and incubation time 10 min. The co-metal ions and surfactants did not affect the dye decolourization significantly. Response surface analysis revealed that predicted values were in agreement with experimentally determined responses. The degradation products were identified by UPLC/MS analysis and degradation pathway was proposed. Besides, phytotoxicity assay revealed a considerable detoxification in response of biodegradation of DY4 dye. C. limon showed promising efficiency for DY4 degradation and could possibly be used for the remediation of textile effluents.


Asunto(s)
Compuestos Azo/metabolismo , Bencenosulfonatos/metabolismo , Biodegradación Ambiental , Citrus/efectos de los fármacos , Colorantes/toxicidad , Peroxidasas/metabolismo , Citrus/enzimología , Espectrometría de Masas
17.
Colloids Surf B Biointerfaces ; 111: 124-33, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-23787279

RESUMEN

In this research, biosorption efficiency of different agro-wastes was evaluated with rice husk showing maximum biosorption capacity among the selected biosorbents. Optimization of native, SDS-treated and immobilized rice husk adsorption parameters including pH, biosorbent amount, contact time, initial U(VI) concentration and temperature for maximum U(VI) removal was investigated. Maximum biosorption capacity for native (29.56 mg g(-1)) and immobilized biomass (17.59 mg g(-1)) was observed at pH 4 while SDS-treated biomass showed maximum removal (28.08 mg g(-1)) at pH 5. The Langmuir sorption isotherm model correlated best with the U(IV) biosorption equilibrium data for the 10-100 mg L(-1) concentration range. The kinetics of the reaction followed pseudo-second order kinetic model. Thermodynamic parameters like free energy (ΔG(0)) and enthalpy (ΔH°) confirmed the spontaneous and exothermic nature of the process. Experiments to determine the regeneration capacity of the selected biosorbents and the effect of competing metal ions on biosorption capacity were also conducted. The biomass was characterized using scanning electron microscopy, surface area analysis, Fourier transformed infra-red spectroscopy and thermal gravimetric analysis. The study proved that rice husk has potential to treat uranium in wastewater.


Asunto(s)
Agricultura , Uranio/aislamiento & purificación , Residuos/análisis , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/economía , Adsorción , Aniones , Biodegradación Ambiental , Cationes , Costos y Análisis de Costo , Concentración de Iones de Hidrógeno , Cinética , Modelos Teóricos , Oryza/química , Oryza/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Termodinámica , Termogravimetría , Factores de Tiempo
18.
Colloids Surf B Biointerfaces ; 75(1): 149-55, 2010 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-19734025

RESUMEN

Biosorption of divalent metal ions, i.e. Pb(II), Cd(II), Zn(II) and Cu(II) onto rice husk activated (RHA) is investigated over pH range (1-10) via batch adsorption technique. The chemical and thermal activation of rice husk with 0.1M HNO(3) and 1M K(2)CO(3) at 473 K enhanced the removal efficiency of RHA (35+/-2.1-99+/-0.5%, 33+/-1.2-97+/-0.6%, 32+/-1.3-96+/-0.8% and 28+/-1.8-95+/-0.9% before and after treatment, respectively). The surface area analysis of RHA by BET (Brunauer, Emmett and Teller) nitrogen adsorption method provided pore area and average pore diameter to be 542+/-2.3m(2)g(-1) and 1076+/-5.6 nm respectively. SEM and FTIR analyses of RHA were carried out to determine the surface morphology and functional groups involved in metal binding mechanism, respectively. The adsorption equilibrium was well described by Freundlich, Langmuir and Dubinin-Radushkevish (D-R) isotherm models by employing (4.8-48, 8.9-89, 15.3-153 and 15.7-157)x10(-5)M solution concentrations of sorbates, respectively, at equilibrium time of 20 min at pH 6 and onto 0.2g of sorbent. The kinetics of mass transfer and intra-particle diffusion for metal ions sorption onto RHA were studied with Lagergren and Morris-Weber kinetic models. The numerical values of thermodynamic parameters indicated the exothermic nature, spontaneity and feasibility of the sorption process. The desorption study of metal components from RHA surface was carried out with 0.1M HCl. The sorption mechanism developed illustrates the strong interactions of sorbates with the active sites of the sorbent coupled with efficient and environmentally clean exploitation of rice waste product.


Asunto(s)
Cationes Bivalentes/aislamiento & purificación , Restauración y Remediación Ambiental/economía , Restauración y Remediación Ambiental/métodos , Metales/aislamiento & purificación , Oryza/metabolismo , Adsorción , Biodegradación Ambiental , Concentración de Iones de Hidrógeno , Residuos Industriales/análisis , Cinética , Oryza/ultraestructura , Soluciones , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Eliminación de Residuos Líquidos
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