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Biorenewable Nanocomposite: Recent Advances and Its Prospects in Wastewater Remediation
Abstract
Because of environmental concerns such as waste accumulation, destruction, and
the inevitable depletion of fossil resources, there has been a great focus on
biorenewable and sustainable resources. Because of their superior features, such
as ease of production, higher mechanical qualities, high thermal stability, and low
environmental impact, biorenewable materials offer significant advantages.
Furthermore, nanocomposites have a number of advantages over conventional
ones. They have been used in wastewater treatment, energy storage, food
technology, the biomedical field, and several other applications. Biorenewable
sources have been either utilized as a matrix or reinforcement in several different
applications. This chapter covers the chemistry, structure, and application of
advanced wastewater treatment using biorenewable resources. It also provides the
detailed information on developments in polymer nanocomposites containing
biorenewable nanomaterials, giving special attention to several promising
applications.
... An unambiguous solution to this debatable question, such that it eliminates the troubleshoots that are associated, would be probably to use NCs that are got from renewable reserves (RR), especially from biorenewable (BRR) [12,13]. The potent resourcefulness of BRR is explicitly vivid in the works of Essawy Shafi et al., whose literatures are based on absorptivity/photo-catalytic activity [14], energy-storage devices/application [15], electro-catalysis/energy-storage/wastewater treatment [16], renewable energy-storage [17], food-packaging [18], agricultural biomass [19], waste-water remediation [20], and electro-chemical/bio-medical fields [21]. ...
The book reviews recent developments in the field of nanomaterials science and technology. Topics covered include methods of fabrication of nanomaterials and nanocomposites, and their applications in areas such as Optoelectronics, Cosmetics, Energy Conversion Cells, Soil and Water Treatment, Agricultural Engineering, Food Sciences, Leather Production, and Photocatalysis.
... Nanocomposites have distinct advantages over conventional materials, including high strength, high rigidity, high durability, low density, high corrosion resistance, gas barriers, and heat resistance [12] . Nanocomposites are applied extensively in numerous disciplines, including the biological sciences, pharmaceutical distribution, and wastewater treatment [13] . Utilizing nanotechnology for wastewater treatment provides innovative solutions for the adsorption of colours, organic compounds, heavy metals, and nutrients [14] . ...
... Nanocomposites have distinct advantages over conventional materials, including high strength, high rigidity, high durability, low density, high corrosion resistance, gas barriers, and heat resistance [12] . Nanocomposites are applied extensively in numerous disciplines, including the biological sciences, pharmaceutical distribution, and wastewater treatment [13] . Utilizing nanotechnology for wastewater treatment provides innovative solutions for the adsorption of colours, organic compounds, heavy metals, and nutrients [14] . ...
The rapid expansion of both the global economy and the human population has led to a shortage of water resources suitable for direct human consumption. As a result, wastewater treatment will inexorably become the primary focus on a global scale. This study might be the first to explore a novel copper-Fusarium oxysporum bio-hybrid nanocomposite [F. oxysporum/PSCO11Cu7]BNC for wastewater treatment that is capable of concurrently removing heavy metals and some microbial pathogens. The crystal structure of [F. oxysporum/PSCO11Cu7]BNC is a Monoclinic 2 with a space group P21/C and an average crystallite size of 35.9 nm. The simulated XRD of [F. oxysporum/PSCO11Cu7]BNC provides a Monoclinic P121/c1(14) structure. TEM results showed that the prepared [F. oxysporum/PSCO11Cu7]BNC powder is in the form of nanoparticles of varying sizes ranging from 22 to 42.07 nm. The direct energy gap for [F. oxysporum/PSCO11Cu7]BNC calculated using density functional theory is 1.476 eV. Exploring the antimicrobial activity of [F. oxysporum/PSCO11Cu7]BNC against different bacterial and fungal species showed the potential of this novel nanocomposite as an antimicrobial agent. Applying this biosynthesized compound for the treatment of Kitchener drainage revealed the promising effect of [F. oxysporum/PSCO11Cu7]BNC in reducing the total count of bacteria and fungi by 90.087 and 100%, respectively, as compared with the controls (54.8% in the case of amoxicillin and 98.57% in the case of nystatin). The efficiency of [F. oxysporum/PSCO11Cu7]BNC as a novel biosorbent has been investigated, and the results showed its capability of treating wastewater since Pb (68.17%), Cr (52.4%), Zn (30.7%), Cd (29.01), and Ni (10.57%) were removed. The findings in this study thus open up the new prospect of the utilization of [F. oxysporum/PSCO11Cu7]BNC as a novel bio-hybrid nanocomposite in wastewater bioremediation and biomedical applications.
... Differences in particle characteristics can be seen when the particle size is below a certain point; this 2 of 14 point is the nanometer stage. This is essential for enhancing characteristics, and these characteristics can be used for product enhancement [15][16][17]. ...
The synthesis of MMT and poly(o-anisidine) (MMT/POA) clay nanocomposites was carried out by using the chemical oxidative polymerization of POA and MMT clay with POA, respectively. By maintaining the constant concentration of POA, different percentage loads of MMT clay were used to determine the effect of MMT clay on the properties of POA. The interaction between POA and MMT clay was investigated by FTIR spectroscopy, and, to reveal the complete compactness and homogeneous distribution of MMT clay in POA, were assessed by using scanning-electron-microscope (SEM) analysis. The UV–visible spectrum was studied for the optical and absorbance properties of MMT/POA ceramic nanocomposites. Furthermore, the horizontal burning test (HBT) demonstrated that clay nanofillers inhibit POA combustion.
The book reviews recent developments in the field of nanomaterials science and technology. Topics covered include methods of fabrication of nanomaterials and nanocomposites, and their applications in areas such as Optoelectronics, Cosmetics, Energy Conversion Cells, Soil and Water Treatment, Agricultural Engineering, Food Sciences, Leather Production, and Photocatalysis.
Nanocomposite and their applications
The structure, porosity, and functionality of synthesized chitosan-clay nanocomposites (NCs) are examined throughout this work in relation to the initial stoichiometry and octahedral cavity occupation of the clay fraction. Dioctahedral and trioctahedral smectite are selected as starting materials. X-Ray Diffraction analysis (XRD) confirms the accomplishment of the NCs synthesis process. The stoichiometry fluctuation implies a crystallite exfoliation process provided that the clay fraction contribution must not reach twice the organic ones. From 1:3 stoichiometry ratio, The intercalation process is enhanced by the interlamellar space (IS) closures, and crystallite size increases with crystallinity degree. According to transmission electron microscopy-energy dispersive X-ray (TEM-EDX) investigations, the exfoliation of "clay-particles" wrapping the organic fraction and the intercalation process occurred as the clay fraction abundance increased. Despite the low proportion approved from the synthesis beginning process, Fourier transform infrared spectroscopy (FTIR) reveals the polymer fraction characteristics absorption bands. The Brunauer, Emmett and Teller (BET) analysis of specific surface area and Barrett-Joyner-Halenda (BJH) Analysis of pore size distribution (PSD) supports the findings from TEM/EDX. For slightly saturated soil solution with Pb²⁺ or Cd²⁺ cation, Atomic absorption spectroscopy (AAS) evaluate the NCs adsorption capacity. The outcomes are extremely positive for dioctahedral smectite.
Herein, a magnetically separable Fe3O4 decorated chitosan was facilely synthesized, systematically characterized, and subsequently employed as a versatile adsorbing material for the adsorption of malachite green and methylene blue dyes. The prepared adsorbent was characteristically examined through Fourier transform infra-red microscopy, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, X-ray diffraction, Brunauere-Emmette-Teller surface area analysis, thermogravimetric analysis, and vibrating-sample magnetometry techniques. The optimum process parameters for MB were observed to be 180 min of contact time, pH 7, and 1.2 g/L of adsorbent dose, and 210 min of contact time, pH 7, and adsorbent dose of 2 g/L was found to be for MG. The time-dependent experimental data were analyzed with different kinetic models, and pseudo-IInd-order was provided the best fit for the adsorption of both the dyes with a high value of the regression coefficient. The adsorption equilibrium data of both the dyes was best explained by Langmuir isotherm, and the maximum sorption capacity of MG and MB was found to be 55.86 and 76.34 mg/g, respectively. Thermodynamic analysis declared that the adsorption of MG and MB onto the Fe3O4 decorated chitosan was endothermic and spontaneous. Moreover, the adsorbent presented good reusability up to three successive ad-/de-sorption cycles, indicating that Fe3O4 decorated chitosan is a promising applicant for treating dye-containing wastewater.
Lignin nanomaterials have emerged as a promising alternative to fossil-based chemicals and products for some potential added-value applications, which benefits from their structural diversity and biodegradability. This review elucidates a perspective in recent research on nanolignins and their nanocomposites. It summarizes the different nanolignin preparation methods, emphasizing anti-solvent precipitation, self-assembly and interfacial crosslinking. Also described are the preparation of various nanocomposites by the chemical modification of nanolignin and compounds with inorganic materials or polymers. Additionally, advances in numerous potential high-value applications, such as use in food packaging, biomedical, chemical engineering and biorefineries, are described.
Clean and safe water is a fundamental human need for multi-faceted development of society and a thriving economy. Brisk rises in populations, expanding industrialization, urbanization and extensive agriculture practices have resulted in the generation of wastewater which have not only made the water dirty or polluted, but also deadly. Millions of people die every year due to diseases communicated through consumption of water contaminated by deleterious pathogens. Although various methods for wastewater treatment have been explored in the last few decades but their use is restrained by many limitations including use of chemicals, formation of disinfection by-products (DBPs), time consumption and expensiveness. Nanotechnology, manipulation of matter at a molecular or an atomic level to craft new structures, devices and systems having superior electronic, optical, magnetic, conductive and mechanical properties, is emerging as a promising technology, which has demonstrated remarkable feats in various fields including wastewater treatment. Nanomaterials encompass a high surface to volume ratio, a high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization which makes them suitable for application in wastewater treatment. In this article we have reviewed the techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology. Furthermore, this review also highlights the fate of the nanomaterials in wastewater treatment as well as risks associated with their use.
The living organisms are created by the carbohydrate biopolymers such as chitosan, carboxymethyl cellulose, alginate and lignin. These carbohydrate biopolymers have been extensively used for environmental applications because they are bio-degradable, bio-compatible, non-toxic and inexpensive. Recently, carbohydrate biopolymers have been used to prepare different nanocomposite adsorbents for treatment of wastewater. These adsorbents explored the removal effectiveness of inorganic pollutants from aqueous solution. This review article discusses the synthesis and application of chitosan, carboxymethyl cellulose, alginate and lignin nanocomposites as adsorbents for heavy metals. Toxic metals can be efficiently absorbed by cross-linker, distributed in aqueous solutions of divalent heavy metal ions to examine their polymer absorption capacity.These nanocomposites were used for the adsorption of highly toxic metals such as Cd²⁺, Pb²⁺ and Zn²⁺ in water. To make heavy metal ion uptake more effective, more functionalization has been implemented such as blending, grafting, or mixing with different nanomaterials with an extra functional group. The integration of the second part into the main polymer chain not only adds functionality but also increases mechanical efficiency, one of the core criteria for adsorbent recyclability. The remediation method of metal ions from wastewater is cheaper as long as the adsorbent is reused. Furthermore, they exhibited good performance for the reuse of spent adsorbents after adsorption-desorption processes including latent fingerprint detection with nanomaterials by using the powder dusting method. Chitosan, carboxymethyl cellulose, alginate and lignin based nanocomposites have demonstrated better adsorption activities due to great physical and chemical properties for the chelation of heavy metals such as Cd²⁺, Pb²⁺ and Zn²⁺ from water and also higher regeneration with various eluents after several desorption-adsorption cycles. In addition, reuse of the spent adsorbents in latent fingerprint detection with different nanomaterials is discussed. Finally, this review article makes recommendations for future studies in light of environmentally favourable and economical applications.
Globally, environmental challenges have been recognised as a matter of concern. Among these challenges are the reduced availability and quality of drinking water, and greenhouse gases that give rise to change in climate by entrapping heat, which result in respirational illness from smog and air pollution. Globally, the rate of demand for the use of freshwater has outgrown the rate of population increase; as the rapid growth in town and cities place a huge pressure on neighbouring water resources. Besides, the rapid growth in anthropogenic activities, such as the generation of energy and its conveyance, release carbon dioxide and other greenhouse gases, warming the planet. Polymer nanocomposite has played a significant role in finding solutions to current environmental problems. It has found interest due to its high potential for the reduction of gas emission, and elimination of pollutants, heavy metals, dyes, and oil in wastewater. The revolution of integrating developed novel nanomaterials such as nanoparticles, carbon nanotubes, nanofibers and activated carbon, in polymers, have instigated revitalizing and favourable inventive nanotechnologies for the treatment of wastewater and gas separation. This review discusses the effective employment of polymer nanocomposites for environmental utilizations. Polymer nanocomposite membranes for wastewater treatment and gas separation were reviewed together with their mechanisms. The use of polymer nanocomposites as an adsorbent for toxic metals ions removal and an adsorbent for dye removal were also discussed, together with the mechanism of the adsorption process. Patents in the utilization of innovative polymeric nanocomposite membranes for environmental utilizations were discussed.
Thiol-lignocellulose sodium bentonite (TLSB) nanocomposites can effectively remove heavy metals from aqueous solutions. TLSB was formed by using –SH group-modified lignocellulose as a raw material, which was intercalated into the interlayers of hierarchical sodium bentonite. Characterization of TLSB was then performed with BET, FTIR, XRD, TGA, PZC, SEM, and TEM analyses. The results indicated that thiol-lignocellulose molecules may have different influences on the physicochemical properties of sodium bentonite, and an intercalated–exfoliated structure was successfully formed. The TLSB nanocomposite was subsequently investigated to validate its adsorption and desorption capacities for the zinc subgroup ions Zn(II), Cd(II) and Hg(II). The optimum adsorption parameters were determined based on the TLSB nanocomposite dosage, concentration of zinc subgroup ions, solution pH, adsorption temperature and adsorption time. The results revealed that the maximum adsorption capacity onto TLSB was 357.29 mg/g for Zn(II), 458.32 mg/g for Cd(II) and 208.12 mg/g for Hg(II). The adsorption kinetics were explained by the pseudo-second-order model, and the adsorption isotherm conformed to the Langmuir model, implying that the dominant chemical adsorption mechanism on TLSB is monolayer coverage. Thermodynamic studies suggested that the adsorption is spontaneous and endothermic. Desorption and regeneration experiments revealed that TLSB could be desorbed with HCl to recover Zn(II) and Cd(II) and with HNO3 to recover Hg(II) after several consecutive adsorption/desorption cycles. The adsorption mechanism was investigated through FTIR, EDX and SEM, which demonstrated that the introduction of thiol groups improved the adsorption capacity. All of these results suggested that TLSB is an eco-friendly and sustainable adsorbent for the extraction of Zn(II), Cd(II) and Hg(II) ions in aqueous media.
The current study focused on the use of gum Arabic grafted polyacrylamide (GA-cl-PAM) hydrogel as a self-template for the in situ synthesize of zinc oxide nanoparticles (ZnO NPs) and the application of synthesized nanocomposite as a potential adsorbent to remove synthetic dyes especially malachite green (MG) from aqueous solution. Different characterization techniques supported in situ synthesis of ZnO NPs onto polymer matrix. The gum Arabic-crosslinked-poly(acrylamide)/zinc oxide nanocomposites (i.e., GA-cl-PAM/ZnO nanocomposite) exhibited much better surface properties as compared to the parental hydrogel matrix. The swelling abilities of the GA-cl-PAM/ZnO nanocomposites with different concentrations of acrylamide were also checked and the nanocomposite with 7.03 × 10–4 mol/L of acrylamide exhibited maximum swelling capacity of 2354%. The nanocomposite adsorbed approximately 99% MG dye with 0.4 g/L adsorbent dose at neutral pH. Adsorption kinetics and isotherm followed pseudo-second-order and Langmuir isotherm models, respectively with the high adsorption capacity of 766.52 mgd/gads at 25 °C. It was observed that the dye molecules were adsorbed onto GA-cl-PAM/ZnO nanocomposite mostly via electrostatic interactions, hydrogen-bonding and pore-diffusion mechanisms. Diffusion of dye molecules within the internal structure of GA-cl-PAM/ZnO nanocomposite followed the combination of both liquid film as well as intraparticle diffusion mechanisms. Furthermore, nanocomposite was applied ten times consecutively to adsorb MG dye from aqueous solution. Therefore, GA-cl-PAM hydrogel have capability to be used for the in situ ZnO NPs synthesis and thus synthesized nanocomposite can be used effectively to treat dyes polluted wastewater.
The aim of this study was to synthesize Fe3O4 nanoparticles and gluten/pectin/Fe3O4 composite hydrogel. This nano-hydrogel was then used to reduce sediment contamination in Lake Urmia (Iran). For this purpose, magnetic nanoparticles were chemically synthesized. Two types of composite Hydrogels including gluten/Fe3O4 and gluten/pectin/Fe3O4 composites were prepared by adding Fe3O4 nanoparticles and pectin to wheat gluten. The properties of Hydrogels were studied by scanning electron microscopy (SEM), Fourier-transform infrared and X-ray diffraction methods. SEM results showed that Fe3O4 particles were seed shape (30–60 nm). The results confirmed the physical interactions between magnetic nanoparticles, pectin and gluten. Subsequently, the prepared Hydrogels were used to reduce the pollution of Lake Urmia sediments. Central composite design was used to investigate the effect of interaction time and interaction temperature of hydrogel with sediment and the type of hydrogel. Qualitative characteristics of the sediments, including heavy metal concentrations (arsenic, barium, cadmium, lead, mercury and chromium), biochemical oxygen demand, and chemical oxygen demand COD, and organic compounds were investigated before and after treatment of sediments with hydrogel. The effect of hydrogel on enhancing sediment quality was investigated. The results showed that in the optimum condition removal efficiency of total heavy metals was 62% and removal efficiency of total organic compounds was 42%. The results also showed that gluten/pectin/Fe3O4 hydrogel had better performance in reducing environmental pollutants of sediment than wheat gluten/Fe3O4 hydrogel.
Industrial wastewater is a universal environmental issue. Numerous organic pollutants, heavy metals, and
non-disintegrating materials are present at extreme concentrations. Presently, removing these pollutants from industrial
wastewater
in
an
effective
way
has
become
a
momentous
issue.
Efficient
purification
procedures
are
needed
to
remove
those
pollutants
before
disposal.
In
this
direction,
wastewater
treatment
has
been
one
of
the
nanomaterial
applications.
Additionally,
nanomaterials
are
innovationally
effective
for
purifying
water
by
using low-budget
nanoadsorbents
and
nanofiltration.
This
review
article
highlights
the
use
of
nanomaterials
for
the
removal
of
different
polluting
materials
from
industrial
wastewater
with
a
special
focus
on
metal
and
metal
oxide
nanomaterials
(NMs),
carbonbased
nanomaterials
(CNMs)
and
nanofiber/nanocomposite
membranes.
The
goal
is to
offer
a
recent
overview
and
references
in
the
area
of
emergent
nanomaterials
used
for
removing
toxic
pollutants
from
real
industrial
wastewater
for
researchers and industrializers.
The present work reported the synthesis of pH-responsive hybrid polymer network
(HPN) of chitosan and gelatine by using glutaraldehyde as a cross-linker. Diferent
reaction parameters like backbone ratio, amount of solvent, pH, the time, the temperature
of reaction mixture and concentration of cross-linker were optimized with
response surface methodology in order to maximize the percentage swelling. The
maximum percentage swelling was obtained 530.48% under most optimized conditions
of the ratio (1:1), pH (7) and cross-linker (0.241 mol/l). Poor loading of drug
in traditional drug delivery is improved by incorporating preformed inclusion complex
of chlorphenamine maleate (CPM) with β-cyclodextrin (1:1) under microwave
conditions directly into the HPN matrix. Further, HPN matrix was used to investigate
the in situ controlled release of CPM under diferent pH conditions at 37 °C.
CPM release showed the best ft to the Peppas–Sahlin equation under all pH conditions
at 37 °C. Thus, HPN prepared by using RSM design is a good device to deliver
the CPM in a controlled manner.
The present study reported the synthesis of novel organic–inorganic hybrid nanocomposite by incorporating tin (IV) based ion exchanger into the hybrid polymer network of chitosan and gelatin prepared under vacuum for the efficient removal of heavy metal ions and toxic dyes from an aqueous fluid. The physicochemical studies such as ion exchange capacity (IEC), chemical stability, thermal stability, pH titration and distribution behaviour studies were also carried out to determine the cation exchange behaviour of the material. The surface morphology and structural properties were studied by the techniques such as FTIR, FESEM, EDS, TEM and XRD. Distribution studies confirmed the synthesized CG/STPNC had the highest selectivity for Pb²⁺ ions (85.3 mL/g). Maximum adsorption of methylene blue (82%) was achieved within 240 min at 500 mg of adsorbent dose, 10 mg/L of the initial concentration of dye, pH of 7 and 30 °C of temperature. Adsorption kinetic data fitted well with pseudo-second order rate model with R² = 0.995. The correlation value 0.95 and favourable RL = 0.21 of adsorption data suggested better fit for Langmuir adsorption. Thus the synthesized nanocomposite ion exchanger was found to be a promising cation exchanger as well as an adsorbent for heavy metal ion and dye removal from textile industrial effluents.
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In this work, gelatin was chemically cross-linked using epichlorohydrin. Then, a series of gelatin-based hydrogel nanocomposites containing CuO nanoparticles were prepared by immersion of gelatin hydrogel in CuCl2 solution with different concentrations. Gelatin was chosen, due to its cheapness, nontoxicity, and biocompatibility. The structure and morphology of hydrogel nanocomposites were characterized by a number of techniques such as FT-IR, XRD, energy dispersive X-ray spectroscopy, and scanning electron microscopy. Then, swelling behavior of synthesized hydrogel nanocomposites in distilled water and different saline solutions was investigated. Their sensitivity to pH, biodegradability, and gel content was determined. Moreover, the water uptake and shrinking kinetics of hydrogel nanocomposites were evaluated. Finally, they were used as drug delivery agent, and the different concentrations effect of CuO nanoparticles present within the hydrogel nanocomposites compared with neat hydrogel on mentioned tests was studied.
The aim of present work to prepare inclusion complexes of amlodipine besylate (APB) drug and β-Cyclodextrin
(β-CD) by microwave and kneading method for sustain release of drug. Microwave irradiation completes the
process in very short time and is more environmentally benevolent method. The complexation of APB with β-CD
was characterized by 1
H NMR and XRD. A nanocomposite was synthesized by incorporating the graphene oxide
(GO) in the polymer network of chitosan (CH) and sodium alginate (ALG) under microwave conditions. Poor
loading of drugs in traditional drug delivery was improved by introducing inclusion complexes (ICs) directly into
the nanocomposite. The operation parameters like ratio of backbones, time, amount of solvent, amount of
graphene oxide and pH were optimized by response surface methodology (RSM) in order to obtain maximum
percentage swelling. From normal plot and pareto chart it was found that ratio of backbones, amount of GO and
solvent are the optimized variables. Furthermore, to get most optimized variables central composite design
(CCD) was analyzed. The ICs were directly loaded into the nanocomposite and their release kinetics was studied
by six kinetic models under different pH at 37 ◦C. The preparatory kinetic analysis, acknowledge that the
cyclodextrin affects the relaxation rate of nanocomposite, leading to slower release of drug.
Green approaches have become a trend for solving ongoing aquatic environmental issues for the very fact that they utterly satisfy the triple lines of sustainability, i.e., environmental and social safeguards, and economic prosperity. Herein, an eco-friendly, and stable new adsorbent with combined adsorption and photocatalytic properties based on clay and biopolymers was successfully designed via a combination of a simple cross-linking way, followed by a non-thermal TiO2 impregnation for the uptake and degradation of water’s soluble pollutants. Emphasis was put on the morphology, pH- sensitive swelling behavior, and the photocatalytic performance of the prepared beads. Thereby, an exhaustive characterization was performed together with an evaluation of the photocatalytic efficiency of the color removal and chemical oxygen demand (COD) reduction of methylene blue (MB) from aqueous solutions. The obtained results ratify the possibility of this biocomposite to have a positive impact in the challenging wastewater sector, by dint of its approved adsorption/ photocatalytic adeptness.
Clean water scarcity combined with environmental impacts of municipal and industrial wastewater necessitates the development of new technologies for clean water production and removal of impurities and toxic contaminants from water and wastewater. Research pertaining to polymer nanocomposites (PNCs) has gained considerable attention in recent years owing to the opportunities that they can provide for a variety of applications. This article first describes the problems and challenges related to water scarcity, quality, availability, and treatment and then summarizes the current water treatment technologies and recent advances to resolve their deficiencies. Recent developments such as the application of biomaterials, nanomaterials, polymers, microbial fuel cells, microwave and ultrasound technologies are summarized. This article provides a relatively comprehensive review on the application of PNCs in water and wastewater treatment over the past 20 years. Different natural and synthetic polymer nanocomposites including clay-, metal-, and carbon-based PNCs applied for water detoxification are discussed. Physics, chemistry, and structural properties of polymer matrices and nanofillers are discussed and the effect of different synthesis approaches of PNCs on water treatment efficiency is distinguished.
Current study focused on the preparation of xanthan gum based novel hydrogel nanocomposites (XG-HNC) via chemical-crosslinking with graphene oxide (GO) for highly efficient adsorption of crystal violet (CV) dye from contaminated wastewater. Initially, GO was functionalized with vinyltriethoxysilane which was further used as crosslinker to prepare HNC of XG with 2-acrylamido-2-methyl-1-propanesulfonic acid and acrylic acid. Adsorption of CV using XG-HNC followed pseudo-second-order rate equation and Langmuir isotherm model with maximum adsorption capacity of 1566.97 mgdye/gads. The dynamics adsorption behavior of XG-HNC was also checked by passing CV dye through a syringe column filled with XG-HNC which showed that this material has potential to treat cationic dyes specifically CV dye contaminated wastewater in large quantities. Furthermore, reuse efficiency of XG-HNC was checked for twenty continuous cycles of adsorption-desorption. Therefore, with unique structure and properties, XG-HNC is a great candidate for cationic dyes removal from wastewater.
The Basil seeds mucilaginous polysaccharide exhibits remarkable physical and chemical properties like high water-absorbing capacity, emulsifying, and stabilizing properties. The metal-organic frameworks are one of the most promising precursors made of metal clusters and organic connectors for the fabrication of advanced adsorbents due to their unique properties. In this study, the bionanocomposite of magnetic zeolitic imidazolate framework-8 was successfully synthesized and applied to adsorb azo cationic and anionic dyes. The synthesized magnetite nanoparticles were pretreated with mucilage extracted from basil seeds to acquire negatively charged magnetite surface, followed by nucleation through attracting zinc cation, and then the growth of metal-organic frameworks which yields high-quality ZIF-8 crystals. The samples were characterized by Field Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infrared Spectrometry, vibrating sample magnetometer, and Brunauer-Emmett-Teller surface area analysis. In the process of adsorption, influencing factors and recycling regeneration were discussed, and the adsorption mechanisms such as kinetics, isotherm, and thermodynamics were explored. The results of the adsorption process showed that maximum adsorption capacities were 9.09 and 13.21 mg/g for Methylene blue and Eriochrome Black T, respectively. The excellent reusability combined with its magnetic separation property makes the nanocomposite a promising adsorbent for the removal of cationic and anionic dyes.
Researchers have recently focused on the advancement of new materials from biorenewable and sustainable sources because of great concerns about the environment, waste accumulation and destruction, and the inevitable depletion of fossil resources. Biorenewable materials have been extensively used as a matrix or reinforcement in many applications. In the development of innovative methods and materials, composites offer important advantages because of their excellent properties such as ease of fabrication, higher mechanical properties, high thermal stability, and many more. Especially, nanocomposites (obtained by using biorenewable sources) have significant advantages when compared to conventional composites. Nanocomposites have been utilized in many applications including food, biomedical, electroanalysis, energy storage, wastewater treatment, automotive, etc. This comprehensive review provides chemistry, structures, advanced applications, and recent developments about nanocomposites obtained from biorenewable sources.
Local fluoride contamination and bacterial infections in potable water have dangerous effects on the human body and are today a global concern. In this study, we have synthesized a pH-responsive bifunctional biopolymer nanocomposite (HAZ) of humic acid with incorporating aluminum zirconium bimetallic oxide by deep freeze–drying method. Fast nucleation and interconnection of nanoparticles form a highly porous network because of sublimation of frozen HAZ. This duo nanocomposite has efficiently worked for fluoride removal and showed potent antibacterial activity against the Escherichia coli Gram-negative and Staphylococcus aureus Gram-positive bacteria. The X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the hydroxyl groups act as a pivot in the ion exchange process of adsorption, each element of bimetallic oxide primarily takes part in the adsorption mechanism. The maximum adsorption capacity of the adsorbent was 180.62 mg/g at pH seven. Thermodynamic parameters like Gibbs free energy change (ΔG⁰), entropy (ΔS⁰), and enthalpy (ΔH⁰) indicate that the process was endothermic, feasible, and taken place by a chemisorption mechanism. This is the first novel freeze–dried bifunctional biopolymer nanocomposite composed of humic acid natural polymer incorporated with Al–Zr metal oxide, and it exhibited three times higher adsorption efficacy with excellent antibacterial action at a concentration of 5 µg/mL of the nanocomposite.
A novel bio-adsorbent based on guar gum (GG) was synthesized through the cross-linked polymerization of N,N'-methylene bis-acrylamide (MBA) onto Fe3O4@ nickel aluminum layered double hydroxide (Ni/Al LDH) @ GG bionanocomposite (BNC) using an in situ growth method. The structural, thermal, and morphological properties of the MLG BNC were studied by different techniques. According to field emission scanning electron microscopy, and transmission electron microscopy, there is a uniform distribution of nanoparticles with a particle size of 40-50 nm in the nanocomposite. MLG BNC was used as Cr (VI) adsorbent, and the effect of pH, concentration, and contact time on adsorption capacity was determined. It was observed that the maximum Cr(VI) adsorption by MLG was 101 mg. g⁻¹ (pH 6, 30 min). The adsorption isotherm was represented the single-layer, and homogeneous adsorption and the high value of R² illustrates a good agreement with Langmuir. The adsorption kinetic was the second-order pseudo-model.
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.
Chitosan a natural linear bio-poly amino saccharide is extensively used for the removal of heavy metals. Brassica Gongylodes a native of Northern Europe is reported to be rich in polyphenols and flavonoids. In present study a novel green nanocomposite has been developed by combining chitosan and Brassica Gongylodes leaf extract. Freshly prepared chitosan nanoparticles embedded with Brassica Gongylodes leaf extract. Developed green nanocomposite was investigated as bio adsorbent for the removal of mercury metal from simulated waste water. Physico-chemical, morphological and elemental characterization of prepared green nanocomposite prior to adsorption was commenced using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope coupled with Energy dispersive x-ray (SEM-EDX) techniques. SEM studies confirm the formation of nanoparticles of chitosan. EDX analysis indicated the presence of new and change in concentration of many compositional elements. In diffractrogram of chitosan nanoparticles impregnated with Brassica Gongylodes leaf extract several diffraction peaks of high angle were observed which were missing in the nanoparticles of chitosan diffractrogram. Batch adsorption results revealed that maximum adsorption of mercury was found with 50 mg of adsorbent when contact time was 45 min at 10 pH. In thermodynamic studies it has been found that process is spontaneous and feasible. For kinetic studies different kinetic parameters, equilibrium sorption capacities, rate constants, and related correlation coefficients were calculated. Result shows that adsorption process could be best defined by the pseudo second order kinetic equation which suggests that adsorption process is carried out probably by chemisorption. Thus study shows that chitosan nano composite embedded with Brassica Gongylodes leaf extract is a promising adsorbent for mercury adsorption from simulated wastewater.
Herein, nanozeolite - carbon nanotube composites with the covalently immobilized enzyme (Laccase) as novel bionanocomposites were synthesized and used for pollutant (Direct Red 23) bio-degradation. Different amounts of CNT (30, 50, and 70 mg) were used to synthesize carbon nanotube -zeolite nanocomposites. The synthesized nanomaterials were silanized and cross-linked by glutaraldehyde. Finally, the enzyme was immobilized on them to prepare Laccase immobilized nanomaterials. The biocatalysts were characterized using Scanning electron microscopy (SEM), X-ray diffraction pattern (XRD), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET), and Transmission Electron Microscopy (TEM). The effect of operational parameters on bio-degradation was investigated and optimized. The synthesized biocatalyst nanocomposite retained more than 95% of its initial activity over the first 5 cycles and its efficiency is still intact. After 10 cycle relative activity decreased gradually to 69%. Results revealed much higher stability for Laccase after the immobilization and 84% of the maximum activity of nanocomposite was preserved at 80 °C. The activity of free Laccase lost over 60% of its activity after 8 days of incubation while the nanocomposite retained about 80% of its maximal activity. They had high storage stability over 8 incubation days and good performance at thermal stability experiments (45 - 80 ºC for 1 h).
In this study, magnetic bionanocomposite of sodium alginate (an anionic polysaccharide), chitosan (a cationic polysaccharide), impregnated with natural zeolite, and cross-linked with glutaraldehyde and CaCl2 in order to improve the stability, are prepared and used to methylene blue removal from aqueous solution. The synthesized magnetic Zeolite/Chitosan/Alginate (MZ/CS/AL) bionanocomposite was analyzed and characterized by FeSEM, EDX, XRD, BET surface area analysis, VSM, TGA, and FTIR techniques. The efficiency of the MZ/CS/AL biosorbent was studied by measuring the uptake using the batch and continuous technique experiments. The effect of contact time, pH, initial concentration of dye, and amount of adsorbent on dye adsorption capacity, kinetics, isotherm, thermodynamics, regeneration, and swelling were investigated. The results showed that the adsorption of methylene blue follows the pseudo-second-order kinetic model and Freundlich isotherm model. The thermodynamic results showed that dye adsorption process with synthetic adsorbent is an exothermic spontaneous process.
This research paper reports the feasibility of utilizing zeolite-Y incorporated hydrogel composite (ZHC) of gum karaya (GK) as a potential adsorbent to treat cationic dyes contaminated wastewater. Initially, the crosslinked hydrogel of GK with N-isopropylacrylamide (NIPAM) and acrylic acid (AA) was synthesized via grafting and subsequently zeolite-Y particle were homogeneously dispersed thought-out the polymer matrix. Changes in the property profile of parental hydrogel polymer after incorporating zeolite-Y were studied using SEM, X-ray diffraction, FTIR and TEM techniques. For dye adsorption studies, brilliant green dye (BG) was taken as the target pollutant. Adsorption isotherm followed Langmuir model with 1461.35 mg/g adsorption capacity and the adsorption kinetics was most appropriately explained using pseudo-second-order model. Diffusion of dye molecules into the internal structure of ZHC was governed collectively by intraparticle and liquid film diffusion mechanisms. Furthermore, ZHC was regenerated and applied six times repeatedly to adsorb dye without much alteration in the performance.
The presence of excess nitrate in groundwater limits it use as a drinking water supply and its removal is critical to balance the nitrogen cycle in aquatic systems. In this study, ultra-thin 2-dimensional Ag-TiO2/γ-Al2O3/Chitosan (Ag-TiO2/Al2O3/CS) nano-composite was synthesized for the fast reduction of nitrate under UVA irradiation from aqueous solutions. As-synthesized nano-composite was well characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier-transform infrared spectroscopy and UV-vis diffuse reflectance spectroscopy. Experimental variables including pH, nitrate concentration, photocatalyst dose and contact time were considered to demonstrate their effect on the rate of nitrate reduction. Formic acid was used as a radical scavenger at optimal concentration of 2:1 (formic acid:nitrate). The results showed that upon UVA irradiation, the synthesized nano-composite exhibited fast nitrate reduction in broad pH range (about 74% removal at pH 11 in 5 minutes reaction time) in diverse water chemical conditions. The Ag-doped and hybrid heterostructures can effectively utilize UV-visible-light to remove nitrate and degrade formic acid. For the 3 cycles the photocatalyst efficiency remained same and after the third cycle, its efficacy decreased gradually. This work suggests 2D Ag-TiO2/Al2O3/CS nano-composite for the fast removal of nitrate in drinking water treatment.
Surface coating of metallic nanoparticles, designed for antibacterial effect, is a major challenge. Herein we report a one-pot, facile, green synthesis of silver bionanocomposite (AgBNC) with water-soluble chitosan (stabilizer) in the presence of citric acid (reducing agent). Three different AgBNC samples with varying sizes (average 39, 51 and 58 nm) were synthesized by varying the concentration of silver nitrate (AgNO3, precursor) alone. It was found that size of the AgBNC increased with increasing concentration of AgNO3. Particle size and its dispersion, surface morphology, and stability up to 3 months were confirmed by DLS, UV–Vis and FTIR spectroscopy, FESEM and TEM study. Furthermore, theoretical simulation using Density Functional Theory (DFT) was performed in order to investigate the mode of interaction of chitosan associated with silver nanoparticles (AgNP). Structural studies imply that though the amino and hydroxyl groups are responsible for stabilization and binding of AgNPs with chitosan, predominant interaction occurs through the amino group of the latter. Size-dependent antibacterial activity of the synthesized AgBNC against one gram-positive (Bacillus subtilis) and one gram-negative (Escherichia coli) bacteria indicated that it had antibacterial effect against both the bacteria and also its toxicity increased with decreasing size of the AgBNC. Bacterial growth curve indicated that synthesized AgBNC maintained its antibacterial activity up to 12 h where efficiency of AgBNC against gram-positive bacteria is more than against gram-negative bacteria.
The main source of nitroaromatic compounds in nature is anthropogenic activities. In the present report, a facile and green method was employed to fabricate highly efficient catalyst to turn toxic nitrophenols to more safe aminophenols. The Fe3O4/Ag@Ca–Al LDH hybrid (FAL hybrid) was synthesized by the Fe3O4 and Ag nanoparticles supported on layer double hydroxide (LDH) and the bionanocomposite (BNC) of this hybrid and starch was prepared via an in situ growth method. The FAL hybrid and BNC were characterized by different techniques. The reduction reaction of 4-nitrophenol in the presence of these catalysts indicated that both of them have high catalytic activity due to their large numbers of hydroxyl groups as capping agent. The comparison rate kinetics study between 4-nitrophenol and 2-nitrophenol showed that the FALS-BNC has higher potential in the case of the para derivative. Also, catalysts were recovered without difficulty and reused after completion of the reduction reaction.
Healthy environment is necessary for growth and development of every living being. The deterioration of ecosystems due to discharge of inorganic and organic pollutants from different industries is one of the major problems. The major impact of these sources has been on our water resources. The literature studies revealed that from the age's humans are using various natural and synthetic materials for water purification. With Gradual development, these materials are modified and newer alternative materials are searched and fabricated. The present study relates to fabrication of novel Gum arabic-crosslinked-poly(acrylamide)/Ni(OH)2/FeOOH nanocomposite hydrogel (GA-cl-poly(AAm)/Ni(OH)2/FeOOH NCH) using simple copolymerization technique. The structural analysis of GA-cl-poly(AAm)/Ni(OH)2/FeOOH NCH was performed by employing diverse modern analytical instrumentations such as transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The HRTEM and SEM micrographs clearly demonstrated the engulfment of Ni(OH)2 and FeOOH particles within the nanohydrogel matrix. The photocatalytic performance of synthesized GA-cl-poly(AAm)/Ni(OH)2/FeOOH NCH was investigated for photodegradation of methylene blue dye. All the parameters such as contact time, pH, concentration of methylene blue, NCH dosage and concentration of H2O2 were optimized. It was noted that 75% methylene blue was degraded at optimized condition using GA-cl-poly(AAm)/Ni(OH)2/FeOOH NCH in presence of H2O2.
The purpose of the present study is to synthesise a self assembled nanocomposite by incorporating GO nanosheets into the polymer network of carboxy methyl cellulose and chitosan without using any initiator and cross-linker system. By incorporation of GO nanosheets, a great enhancement in various properties likes surface roughness, percentage swelling (from 2347% to 4633.8%) and adsorbent properties. The nanocomposite samples were investigated for removal of various kinds of dyes from waste water sources and were found highly selective for different cationic dyes. The adsorbent showed 97.9% removal of BG in 7 h whereas 100% removal of MB in just 1.5 h. The adsorption kinetics statistics fitted well in pseudo-second order rate equation. The correlation values and favourable RL of adsorption data suggested better fit for Langmuir adsorption for both the dyes.
A novel Fe(III) crosslinked poly (vinyl alcohol) (PVA)/chitin nanofiber composites were prepared for dye adsorption from water. The adsorbents were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. The effects of Fe(III) content and chitin nanofibers (NFs) incorporation on the dye removal efficiency of adsorbents were investigated. The adsorption influencing parameters such as solution pH, contact time and initial dye concentration were optimized for maximum methyl orange (MO) adsorption. With loading of chitin NFs, the dye removal efficiency of PVA/Fe(III) adsorbents was noticeable increased. In addition, the dye removal efficiency did not show significant decline in alkaline solution in the presence of chitin NFs. Kinetics, isotherms and thermodynamics of dye adsorption process were also thoroughly studied. The adsorption data were better fitted with the pseudo-second-order kinetics and Freundlich isotherm model. PVA-chitin NFs-Fe(III) adsorbent exhibited a high maximum adsorption capacity of 810.4 mg/g for MO adsorption. Furthermore, reuse experiments revealed that the adsorption efficiency remained almost constant during five cycles of adsorption/desorption. At last, the possible mechanism for dye adsorption-desorption was proposed. The obtained results revealed that the developed bionanocomposites could be considered as promising recyclable adsorbents for wastewater treatment.
Sustainable bio nano composite comprising of nanoMgS/FeS doped cellulose nanofibres (FeMgSCNF) was prepared, characterized by various techniques and assessed for the decontamination of Cr(VI). Cellulose nanofibres (CNF) acts as a template and stabilizer and prevents agglomeration of FeS/MgS nano particles. MgS present in the nano-composite provides a barrier to suppress aerial oxidation of Fe(II) and provided additional source of sulfide ions. An adsorption capacity in the order of 142.8 mg/g of the bionano composite was exhibited towards hexavalent chromium. Both FeSCNF and FeMgSCNF followed pseudo first order and pseudo second order kinetics with regression coefficients >0.96. X-ray photoelectron spectroscopy (XPS) studies indicated that decontamination of Cr(VI) follows the route of electrostatic attraction, ion-exchange followed by reduction of Cr(VI) to Cr(III) and immobilization of Cr(III) as chromic oxide and Fe-Cr mixed oxide. Toxicity characteristics leaching tests revealed the efficacy of immobilization. Finally the developed sorbents were successfully applied to the removal of chromium from tannery waste effluents.
In Egypt, the improvement in water quality of drainage water has become an important source of irrigation due to the depletion of freshwater resources, increase in population density, industrial activities, land reclamation projects and water stress linked to changes in climate conditions. This work aimed to improve the drainage water quality by using low-cost techniques such as chitosan–silver nanoparticles or immobilized microbial isolates, to use in various activities like irrigation and fish farming. Over a year period starting form January, 2016, synthesized chitosan–silver nanoparticle was characterized by transmission electron microscopy and Fourier-transform infrared and UV–visible spectrum. The bactericidal effect of chitosan–silver nanoparticles was achieved at a concentration of 2 g/l from 40 min to 3 h to remove total coliform, fecal coliform, Staphylococcus aureus, fecal streptococci and Pseudomonas aeruginosa from 198 × 10⁵, 84 × 10⁵, 16 × 10³, 4 × 10³ and 5 × 10³ to zero CFU/ml⁻¹, respectively, while uptake decreased with using immobilized microbial isolates to 38%, 76.1%, 64.6%, 64.4% and 54.7%, respectively. The removal efficiency of BOD, COD, TSS, turbidity and ammonia on chitosan–silver nanoparticles showed a sharp decrease of 89%, 80%, 81%, 90% and 93%, respectively; in contrary, the removal efficiency for immobilized microbial isolates was 38%, 76.1%, 64.6%, 64.4% and 54.7%, respectively. Finally, improvement in El-Gharbia drain water quality by chitosan–silver nanoparticles is higher than immobilized microbial isolates.
The present work represents RSM-CCD (Response Surface Methodology integrated Central composite Design) optimized synthesis scheme of semi-IPN (semi interpenetrating network) NaAla-Gel-cl-polyAAm and ZnS nanocomposite adsorbent NaAla-Gel-cl-polyAAm/ZnS. Under optimized reaction parameters semi-IPN NaAla-Gel-cl-polyAAm showed maximum swelling percentage of 3191.73%. Maximum dye removal percentage (97.37%) was observed with ZnS nanocomposite for the removal of biebrich scarlet. The adsorption isotherm data indicated that Langmuir and Freundlich adsorption isotherm fitted well for biebrich scarlet (R2 = 0.964) and crystal violet (R2 = 0.960), respectively. ΔG°, ΔH° and ΔS° values indicated the thermodynamic feasibility of the reaction. Excellent recyclability and reusability of the adsorbent materials suggested their applicability towards textile industry and water purification purpose.
Nano zirconium phosphate (ZrP) was synthesized hydrothermally using an autoclave and was further self-assembled with chitosan to form bionanocomposite CZrP. The structural characteristics of ZrP and CZrP were investigated by Fourier Transform Infrared (FT-IR), X-Ray Diffraction (XRD), Energy Dispersive X-Ray (EDX), X-Ray Photelectron Spectroscopy (XPS), Electron Spin Resonance (ESR), Raman spectroscopy and Transmission Electron Microscopy (TEM) techniques. During the course of characterization, unique surface defects and superoxide anions stabilized on ZrP and CZrP were observed for the first time. The potential of the synthesized nanocomposite was investigated for adsorption of Cr(VI), a copper phthalocynanine dye- Reactive blue-21 (RB-21), azo dye- Reactive Red 141 (RR-141), a xanthene dye-Rhodamine-6G as well as binary mixtures of the dyes. Further the potential of CZRP as catalyst for the hydrogen peroxide degradation of dyes was investigated. The dyes were degraded in ˜10 min and CZrP exhibited stability during multiple runs of degradation of the dyes.
A novel method to obtain catalytic bio-nanocomposites based on chitosan containing different amounts of gold nanoparticles generated in situ is reported. The formation of gold nanoparticles takes place in solid phase assisted by a heating induced process. This method only involves the use of chitosan biopolymer and a gold salt precursor. Unlike other methods the addition of external reducing and stabilizing agents to generate gold nanoparticles, is not needed because these roles are played by chitosan. Therefore, the striking properties of chitosan (e.g., high functionality, biodegradability and biocompatibility) are profited, in order to design a facile and green route of synthesis. Additionally, the described method allows to vary the amount and size of the gold nanoparticles contained in the bio-nanocomposite by using different gold ion compositions and temperatures of heating process. Finally, the bio-nanocomposite performance as heterogeneous catalyst on the reduction of p-nitrophenol (4-NP) to p-aminophenol (4-AP) as a model system was assessed. The results showed a significant catalytic effect that increases as the content of gold nanoparticles in the bio-nanocomposite also increases.
The present work reports the comparison study of Chitosan-Gelatin based hydrogels with their nanocomposite ion exchangers synthesized under microwave conditions for the adsorption and photodegradation of the cationic dyes. In this report, the hydrogel based on Chitosan-Gelatin, more selective for anionic dyes is modified to nanocomposite ion exchanger by incorporating the zirconium (IV) selenophosphate to make it selective for cationic dyes. The nanocomposite was investigated with a tremendous hike in the degradation capacity (99% from 12%) of MB after being modified to nanocomposite ion exchanger. Adsorption process followed Langmuir adsorption (Qo = 10.46 mgg⁻¹) and non linear PFO kinetic model with k1, qe (calculated), R², RMSE = 0.011, 1.02 (mgg⁻¹), 0.996, and 0.01709 respectively.
Nickel doped polyaniline/cellulose bionanocomposites have been synthesized via in-situ polymerization of aniline and hydrothermally prepared nickel nanoparticles. The as prepared materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Cyclic Voltammetry (CV) was used to determine the electrochemical surface area (ECSA) of the materials by using the electrochemical double layer capacitance (EDLC) data. SEM images reveal that synthesized nanocomposites contain spherical Ni nanoparticles scattered uniformly within PANI-Cellulose matrix. The as prepared materials exhibited significant degradation of reactive orange (RO-16) dye under visible light. Incorporation of Ni nanoparticles in to the polymer matrix causes strong adsorption of dye in case of PANI/C/Ni, PANI/Ni as compared to that of PANI. The photodegradation of RO-16 was achieved by the electron-hole pair separation and formation of reactive species by trapping of the photo generated electron from the surface of photo catalyst. Scavengers were added to identify the primary reactive species. Fluorescence spectroscopy was to study the recombination behavior of charge carriers (electron-hole pair) during photodegradation. Moreover, the anti-fungal nature of the bionanocomposites was also examined and the materials were found to be effective in growth control of two pathogenic fungal strains-Rhizoctonia solani and Alternaria alternate.
Present work reports the synthesis of Chitosan-Gelatin @ zirconium (IV) selenophosphate nanocomposite (CH-GEL/ZSPNC) ion exchanger. CH-GEL/ZSPNC was characterized by different characterization techniques using Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray spectroscopic studies (EDX), High resolution-transmission electron microscopy (HRTEM), powdered X-ray diffraction (PXRD) and Thermal gravimetric analysis (TGA). Physicochemical properties like ion exchange capacity (IEC), thermal stability, elution behaviour, eluent concentration, pH titration, chemical stability and distribution coefficient (Kd) of (CH-GEL/ZSPNC) ion exchanger were investigated. The ion exchange capacity of the synthesized nanocomposite was improved by one and half order (2.4 mequiv/g) as compare to its inorganic moiety (1.6 mequiv/g) and highest among a number of nanocomposite ion exchangers already reported in the literature. CH-GEL/ZSPNC ion exchanger was found to be thermally stable and retained 58.3% ion exchange capacity (IEC) of its original IEC value at 400 °C. Pb (II) and Cu (II) was found to possess the highest values of Kd. Binary separation of divalent heavy metal ions has been conducted on the basis of Kd values. Photocatalytic degradation of the Rhodamine-B (RD-B) dye was explored with CH-GEL/ZSPNC in the solar radiations. It has been investigated that 84% of the RD-B dye was degraded after 160 min of photo exposure. Photodegradation of the RD-B follows the pseudo-first-order kinetics. Thus, the synthesized CH-GEL/ZSPNC ion exchanger is found to be a superior advanced nanocomposite photocatalyst for environmental remediation of dye pollutants, heavy metal ion removal, the binary separations and possessed tremendous reusability potential.
Pesticides are organic toxic materials and, nowadays, their removal from water is globally required. Herein, modified natural fabrics based on cotton and wool were designed to eliminate pesticides from water. Firstly, fabrics were modified with polyethyleneimine (PEI) to increase the active sites. Modification of fabrics was affirmed by electron microscopy and infrared spectroscopy. PEI-modified fabrics were then applied in the elimination of pirimiphos-methyl and monocrotophos pesticides. The adsorption reactions of pesticides onto fabrics were fitted well to pseudo-second order and the rate of reaction was accelerated by PEI-modification. Adsorption profiles of pesticides have complied with Langmuir isotherm. Maximum adsorption capacities of pesticides were significantly grown from 131.6 to 172.4 mg/g to 333.3–454.6 mg/g for cotton and from 153.4 to 200.0 mg/g to 500.0–625.0 mg/g for wool fabrics, after modification with 10% PEI. A Linear correlation between adsorption capacities and nitrogen contents was observed. Despite the reduction in adsorption capacities detected by recovering process due to the lowering of nitrogen contents, adsorption capacities results were quite high after fifth recovering cycles. Therefore, the prepared PEI-modified fabrics are considered as a safely applicable and highly adsorptive material for the efficient elimination of pesticides from water with a quite good reusability.
The present study proposes the synthesis and optimization of a hybrid polymer network, consisting of chitosan, gelatine cross-linked by glutaraldehyde under microwave conditions. Backbone ratio, amount of solvent, pH, time and concentration of crosslinker are taken as process variables and optimized with RSM in order to maximize the percentage swelling. ANOVA model fits were made for the data and gave the linear model as the best fit with a predicted R² = 0.9747. The maximum desirability was found at pH = 7 with the percentage swelling of 508.061%. β-cyclodextrin is a cyclic oligosaccharide containing at least 7 D-(+) glucopyranose units attached by α-(1, 4) glucosidic bonds. Its tendency to form host-guest complexes promoted its application as a drug carrier. Poor loading of drug in traditional drug delivery is improved by incorporating preformed inclusion complex of Atenolol with β-cyclodextrin (1:1) under microwave conditions directly into the HPN matrix. Further, HPN matrix was explored for the in situ controlled release of ATL under different pH conditions at 37° C. ATL release showed the best fit to the Ritger-Peppas and Peppas-Sahlin equation. Thus HPN prepared by using RSM design is a good device to deliver the ATL in a controlled manner.
Chitosan-Guar gum blend Silver Nanoparticle bionanocomposite (CGS) was synthesized by incorporating palm shell extract capped nano silver particles during the formation of blend. The nanocomposite was characterized with IR, TEM, XRD and Raman spectroscopic techniques. The catalyst was further investigated for degradation of single and binary mixture of dyes as well as for reduction of nitrophenol. Further the prepared catalytic composite CG could be conveniently separated from the aqueous solution after the reaction andcould be reused upto three cycles without loss in activity.
In the present study, a novel biodegradable Xanthan gum/montmorillonite (XG/MMT) bionanocomposite has been successfully synthesized and was explored for the removal of Pb (II) from synthetic and industrial wastewater. SEM, TEM and FTIR techniques were employed for the characterization of (XG/MMT) bionanocomposite. The effects of several parameters such as pH, contact time and initial metal ion concentration were analyzed. The experimental data was investigated using equilibrium isotherm and kinetic models. The result showed that the pseudo-second order and Freundlich were the best fitted models for the adsorption process. Thermodynamic study illustrates that the adsorption was endothermic and spontaneous in nature. Finally, the worthy regenerative efficacy (up to five cycles) using 0.05M HCl of bionanocomposite proved as economically promising adsorbent for practical applications. Therefore, the findings suggests that the present (XG/MMT) bionanocomposite can be utilized as a potential and novel adsorbent for the removal of toxic heavy metal from wastewater.
The aim of this study was investigate of arsenite adsorption on a hybrid polymer based on a polystyrene/divinylbenzene macroporous anion exchanger containing cupric oxide deposited within its porous structure. The study included batch kinetic and equilibrium experiments, and investigation of influence of the pH, regeneration of spent adsorbent and the column process on arsenic(III) adsorption. The experimental data were evaluated using kinetic, isotherm and fixed-bed column models. The adsorption capacity calculated from the Langmuir model was 6.61 mg As(III) g⁻¹. The adsorption rate was controlled by both chemisorption of arsenic on the adsorbent surface and external diffusion, and at a higher initial As(III) concentration also by intraparticle diffusion. The spent adsorbent was easily regenerated with 1.0 M NaOH solution. Based on batch adsorption studies and X-ray photoelectron spectroscopic analyses a mechanism of As(III) adsorption was proposed. Arsenite removal proceeded in two stages: oxidation to arsenate on the CuO surface, followed by an ion exchange reaction. The studied hybrid polymer also showed very good adsorption characteristics under the dynamic regime. The S-shape of breakthrough curves and insignificant influence of bed height, initial concentration and flow rate on the adsorption capacity confirmed its applicability in water treatment.
The advances in the field of biomaterials have led to several studies on alternative biocompatible devices and to their development focusing on their properties, benefits, limitations, and utilization of alternative resources. Due to their advantages like biocompatibility, biodegradability, and low cost, polysaccharides have been widely used in the development of hydrogels. Among the polysaccharides studied on hydrogels preparation, chitosan (pure or combined with natural/synthetic polymers) have been widely investigated for use in biomedical field. In view of potential applications of chitosan-based hydrogels, this review focuses on the most recent progress made with respect to preparation, properties, and their salient accomplishments for drug delivery and tissue engineering.
Excessive nutrients (N and P) are among the most concerned pollutants in surface and ground waters. Herein, we report nanoscale zero-valent iron/nickel supported on zeolite (Z-Fe/Ni) for simultaneous removal of nitrate and phosphate from aqueous solution. The synergistic effect between zeolite and Fe/Ni bimetallic nanoparticles, as well as the removal mechanism was investigated systematically. The characterization by BET, TEM and XPS demonstrated that nanoscale zero-valent iron/nickel was successfully loaded onto zeolite, and Z-Fe/Ni exhibited larger specific surface area and more uniform dispersion than unsupported Nano-Fe/Ni. XRD, FTIR and XPS analysis revealed that the Fe⁰ supported on the surface of zeolite were protected from oxidization. Batch experiments showed that nitrate reduction by Z-Fe/Ni was not sensitive to initial solution pH, while phosphate removal was affected. Moreover, Z-Fe/Ni displayed higher equivalent N2 selectivity (85.5%) and less ammonium release than that of Nano-Fe/Ni, which was mainly attributed to the selective ion-exchange of NH4⁺ by zeolite, indicating the significant synergistic effect of the combination of zeolite and Nano-Fe/Ni. The influence of one pollutant on the removal of the other manifested that the presence of phosphate inhibited nitrate reduction through forming Fe-P complex, while the phosphate removal was promoted by the present nitrate via accelerating corrosion of Fe. Nitrate reduction pathway identification and FTIR, XPS analysis confirmed that reduction and complexation were the dominant mechanism for nitrate and phosphate, respectively.
In the current study, a facile and an eco-friendly manganese oxide nanoparticles dispersed in chitosan (CS-MnO2) nanocomposite was synthesized. A chemical precipitation method was used for the product synthesis. The product characterization was performed using various spectroscopic techniques such as X-ray scattering, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and zeta potential which confirmed its successful formation. The CS-MnO2 nanocomposite was evaluated in the Pb2+ ions adsorption from it aqueous solution. The CS-MnO2 showed an approvable accomplishment for the removal of Pb2+ ions and evidence was provided from the adsorption experiments. The efficiency of adsorbent did not change much even after 5 cycles of reuse. Therefore, CS-MnO2 would serve as promising adsorbent. Additionally, the CS-MnO2 nanocomposite showed low to moderate antibacterial efficacy against Escherichia coli and Staphylococcus aureus by inhibiting nearly 50% of the bacterial growth. Colony forming units method was used in the antibacterial studies which showed that the bio-nanocomposite had moderate antibacterial activity against the stated strains of bacteria.