Functionalization of polymers and nanomaterials for water treatment, food packaging, textile and biomedical applications: a review

AbstractThe inert nature of most commercial polymers and nanomaterials results in limitations of applications in various industrial fields. This can be solved by surface modifications to improve physicochemical and biological properties, such as adhesion, printability, wetting and biocompatibility. Polymer functionalization allows to graft specific moieties and conjugate molecules that improve material performances. In the last decades, several approaches have been designed in the industry and academia to graft functional groups on surfaces. Here, we review surface decoration of polymers and nanomaterials, with focus on major industrial applications in the medical field, textile industry, water treatment and food packaging. We discuss the advantages and challenges of polymer functionalization. More knowledge is needed on the biology behind cell–polymer interactions, nanosafety and manufacturing at the industrial scale

Influence of relaxation modes on membrane fouling in submerged membrane bioreactor for domestic wastewater treatment

Relaxation and backwashing have become an integral part of membrane bioreactor (MBR) operations for fouling control. This study was carried out on real municipal wastewater to evaluate the influence of different operational strategies on membrane fouling at equivalent water yield. Four relaxation modes (MBR10+0, MBR10+1, MBR10+1.5 and MBR10+2) were tested to analyze membrane fouling behavior. For the optimization of relaxation modes, fouling rate in terms of trans-membrane pressure, hydraulic resistances and characteristics of fouling fractions were analyzed. It has been observed that cake layer resistance was minimum in MBR10+1.5 but pore blockage resistance was increased in all relaxation modes. Moreover, high instantaneous flux contributed significantly to fouling rate at the initial stage of MBR operations. Relaxation modes were also efficient in removing irreversible fouling to some extent. Under all relaxation modes, COD removal efficiency ranged from 92 to 96.5%. Ammonium and TP removal were on the lower side due to the short solids and hydraulic retention time

Effect of different co-solvents on biodiesel production from various low-cost feedstocks using Sr–Al double oxides

The main objective of the present paper comprises the investigation of biodiesel production from low-cost feedstock such as lard oil and waste cooking oil (WCO) using Sr–Al double oxides. Nanocatalyst was characterised FTIR, XRD, SEM, TEM, BET and XPS. The Sr:Al with 3:1 M ratio showed the best catalytic activity in the conversion of both oils to fatty acid methyl ester. The effect of acetone and tetrahydrofuran (THF) as a co-solvent for transesterification were compared and the best result was obtained with 5% THF. The mutual effect of the nanocatalyst and co-solvent on biodiesel production was investigated. The characterisation of biodiesel synthesised from lard oil and WCO was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters for transesterification reaction was analysed and the yield was determined by 1H NMR. The maximum yield of 99.7% and 99.4% of lard oil methyl ester and WCO biodiesel were observed with a 0.9 wt% catalyst amount, 1:5.5 oil to methanol ratio in a reaction time of 45 min at 50 °C and 60 °C, respectively. The properties of biodiesel from lard oil and WCO were determined by the EN 14214 method. The regeneration, characterisation and reusability of regenerated catalyst was observed.peerReviewe

Fabrication of carbon nanotubes reinforced silica composites with improved rare earth elements adsorption performance

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A novel approach for synthesis of exfoliated biopolymeric-LDH hybrid nanocomposites via in-stiu coprecipitation with gum Arabic: Application towards REEs recovery

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Understanding the factors affecting the adsorption of Lanthanum using different adsorbents: A critical review

Over the past few decades, removal and recovery of Lanthanum (La) have received great attention due to its significance in different industrial processes. In this review, the application of various adsorbents viz. biosorbents, commercial and hybrid materials, nanoparticles, nanocomposites etc. have been summarized in terms of the removal and recovery of La. The influence of various operating parameters including pH, dosage, contact time, temperature, coexisting ions, adsorption kinetics, isotherm and thermodynamics were investigated. Statistical analysis of the obtained data revealed that 60% and 70% of the authors reported an optimum pH of 4-6 and a dose of 1-2 g/L, respectively. It can be concluded on the basis of an extensive literature survey that the adsorbent materials (especially hybrids nanocomposites) containing carboxyl, hydroxyl and amine groups offered efficient La removal over a wide range of pH with higher adsorption capacity as compared to other adsorbents (e.g., biosorbents and magnetic adsorbents). Also, in most cases, equilibrium and kinetics were followed by Langmuir and pseudo second-order model and adsorption was endothermic in nature. To evaluate the adsorption efficiency of several adsorbents towards La, desorption and regeneration of adsorbents should be given due consideration. The main objective of the review is to provide an insight into the important factors that may affect the recovery of La using various adsorbents

Understanding the factors affecting the adsorption of Lanthanum using different adsorbents: A critical review

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Degradation and mineralization of phenol in aqueous medium by heterogeneous monopersulfate activation on nanostructured cobalt based-perovskite catalysts ACoO 3 (A = La, Ba, Sr and Ce): Characterization, kinetics and mechanism study

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N- and O- ligand doped mesoporous silica-chitosan hybrid beads for the efficient, sustainable and selective recovery of rare earth elements (REE) from acid mine drainage (AMD): Understanding the significance of physical modification and conditioning of the polymer

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A review on the effectiveness of nanocomposites for the treatment and recovery of oil spill

The introduction of unintended oil spills into the marine ecosystem has a significant impact on aquatic life and raises important environmental concerns. The present review summarizes the recent studies where nanocomposites are applied to treat oil spills. The review deals with the techniques used to fabricate nanocomposites and identify the characteristics of nanocomposites beneficial for efficient recovery and treatment of oil spills. It classifies the nanocomposites into four categories, namely bio-based materials, polymeric materials, inorganic-inorganic nanocomposites, and carbon-based nanocomposites, and provides an insight into understanding the interactions of these nanocomposites with different types of oils. Among nanocomposites, bio-based nanocomposites are the most cost-effective and environmentally friendly. The grafting or modification of magnetic nanoparticles with polymers or other organic materials is preferred to avoid oxidation in wet conditions. The method of synthesizing magnetic nanocomposites and functionalization polymer is essential as it influences saturation magnetization. Notably, the inorganic polymer-based nanocomposite is very less developed and studied for oil spill treatment. Also, the review covers some practical considerations for treating oil spills with nanocomposites. Finally, some aspects of future developments are discussed. The terms "Environmentally friendly, " "cost-effective, " and "low cost " are often used, but most of the studies lack a critical analysis of the cost and environmental damage caused by chemical alteration techniques. However, the oil and gas industry will considerably benefit from the stimulation of ideas and scientific discoveries in this field.Peer reviewe