Alleviation of heavy metals chromium, cadmium and lead and plant growth promotion in Vigna radiata L. plant using isolated Pseudomonas geniculata.

Plants exposed to heavy metals (HMs) stress negatively affect their development and production capacity. Chromium (Cr), Cadmium (Cd), and Lead (Pb) are the most common hazardous trace metals in agriculture. The physiological, biochemical, and molecular characteristics of crops are being affected. Phytoremediation is a method to alleviate heavy metals from the contaminated soil. The study aims to evaluate the phytoremediation ability of Vigna radiata L. (mung bean) in the absence and the presence of multi-metal tolerant and plant growth promoting Pseudomonas geniculata strain TIU16A3 isolated from soil of tannery industrial estate, Kolkata, West Bengal, India. The strain was further assessed with increasing concentrations of Cr, Cd, and Pb (10, 20, 40, and 80 µg/mL) when the mung bean plant was a test crop. The strain significantly increased plant growth, chlorophyll content, increased level of antioxidant enzymes such as superoxide dismutase, peroxidase, and catalase, and decreased oxidative stress indicators like H2O2 and electrolyte leakage in the presence of Cr, Cd, and Pb as compared to plants grown in the absence of Pseudomonas geniculata strain. Shoot length responsive gene (Aux/IAA) in the presence of heavy metal alone and Pseudomonas geniculata treated Cd and Cr showed higher relative expression of (Aux/IAA) compared to Pb. Due to these intrinsic abilities, Pseudomonas geniculata strain TIU16A3 can be a plant growth promoter and thus can help in the remediation of heavy metal (Cr, Cd, and Pb) contaminated soil.

Synthesis of mesoporous Fe/Al/La trimetallic oxide for photodegradation of various water-soluble dyes: Kinetic, mechanistic, and pH studies.

Phase pure, trigonal, mesoporous Fe/Al/La trimetallic nano-oxide (abbreviated as FAL) was synthesized using energy efficient chemical route with bandgap 1.97 eV and SBET = 50.02 m2/g and an average pore size of 8.95 nm for photodegradation of azo (di and tri) and thiazine class of dyes successfully. The valence band and conduction band potentials were calculated using the Mott-Schottky plot. The highest photodegradation efficiency was 93.85 ± 2% for reactive black 5 (RB5) at pH 7 under solar irradiation. The phase formation of FAL was confirmed by PXRD, TEM, and HRTEM analyses. The other characterizations include FESEM, Raman, EPR, UV, HPLC, LC-MS, etc. The presence of the metal centers and their corresponding oxidation states were confirmed by the SAEDS, elemental mapping, and XPS analyses respectively. FAL was also able to photodegrade direct blue 71 (DB71) and methylene blue (MB) under the same condition at different pH efficiently (pH 2-11). The photodegradation obeyed the pseudo-1st-order kinetics and was reusable up to 5 successive cycles. This study may be an efficient tool to meet UNs' SDG:6.

A simple chemical method for the synthesis of Cu2+ engrafted MgAl2O4 nanoparticles: Efficient fluoride adsorbents, photocatalyst and latent fingerprint detection.

An adaptable, energy efficient chemical process is employed to synthesize Cu2+ engrafted MgAl2O4 nanoparticles (Mg1-xCuxAl2O4, x=0, 0.1, 0.3, 0.5 abbreviated as MCA0, MCA1, MCA3, and MCA5 respectively), using chelating ligand and the calcination temperature was determined by the thermogravimetric analysis of the precursor mass. They acted as good fluoride adsorbent in the presence of co-ions, different pH (2-11) via chemisorption revealed from Fourier-transform infrared spectroscopy (FTIR) and photodegraded Methylene Blue (MB). The satisfactory results were for MCA1 (specific surface area 25.05m2/g) with 97% fluoride removal at pH7.0 for the 10mg/L initial fluoride concentration for 1.5g/L adsorbent dose with 45min contact time obeying the Langmuir isotherm model with negative thermodynamic parameters and 4mmol of MCA3 with 98.51% photodegradation for 10-5mol/LMB solution obeying pseudo-second-order and pseudo-first-order kinetics respectively. The proposed photodegradation mechanism of MB was established by the FTIR and high-performance liquid chromatography (HPLC) analysis. The nanoparticles are cubic, estimated through X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The band gap energies, grain size, and the effective working pH were estimated by diffuse reflectance spectra (DRS), scanning electron microscope (SEM), and zero-point potential analysis respectively. A soil candle with MCA1 also fabricated for the household purpose and tested with some fluorinated field samples. The MCA3 was able to enhance the latent fingerprint on smooth surfaces.

Efficacy of new generation biosorbents for the sustainable treatment of antibiotic residues and antibiotic resistance genes from polluted waste effluent.

Antimicrobials are frequently used in both humans and animals for the treatment of bacterially-generated illnesses. Antibiotic usage has increased for more than 40% from last 15 years globally per day in both human populations and farm animals leading to the large-scale discharge of antibiotic residues into wastewater. Most antibiotics end up in sewer systems, either directly from industry or healthcare systems, or indirectly from humans and animals after being partially metabolized or broken down following consumption. To prevent additional antibiotic compound pollution, which eventually impacts on the spread of antibiotic resistance, it is crucial to remove antibiotic residues from wastewater. Antibiotic accumulation and antibiotic resistance genes cannot be effectively and efficiently eliminated by conventional sewage treatment plants. Because of their high energy requirements and operating costs, many of the available technologies are not feasible. However, the biosorption method, which uses low-cost biomass as the biosorbent, is an alternative technique to potentially address these problems. An extensive literature survey focusing on developments in the field was conducted using English language electronic databases, such as PubMed, Google Scholar, Pubag, Google books, and ResearchGate, to understand the relative value of the available antibiotic removal methods. The predominant techniques for eliminating antibiotic residues from wastewater were categorized and defined by example. The approaches were contrasted, and the benefits and drawbacks were highlighted. Additionally, we included a few antibiotics whose removal from aquatic environments has been the subject of extensive research. Lastly, a few representative publications were identified that provide specific information on the removal rates attained by each technique. This review provides evidence that biosorption of antibiotic residues from biological waste using natural biosorbent materials is an affordable and effective technique for eliminating antibiotic residues from wastewater.

Humic acid-nanoceria composite as a sustainable adsorbent for simultaneous removal of uranium(VI), chromium(VI), and fluoride ions from aqueous solutions.

In this article, the multifunctional behavior of novel, efficient, and cost-effective humic acid-coated nanoceria (HA@CeO2 NPs) was utilized for the sorptive removal of U(VI), Cr(VI), and F- ions at different conditions. The production cost of HA@CeO2 was $19.28/kg and was well characterized by DLS, FESEM, HRTEM, FTIR, XRD, XPS, and TGA. Batch adsorption study for U(VI) (at pH ~ 8), Cr(VI) (at pH ~ 1), and F- (at pH ~ 2) revealed that the maximum percentage of sorption was > 80% for all the cases. From the contact time experiment, it was concluded that pseudo-second-order kinetics followed, and hence, the process should be a chemisorption. The adsorption study revealed that U(VI) and Cr(VI) followed the Freundlich isotherm, whereas F- followed the Langmuir isotherm. Maximum adsorption capacity for F- was 96 mg g-1. Experiments in real water suggest that adsorption is decreased in Kaljani River water (~ 12% for Cr(VI) and ~ 11% for F-) and Kochbihar Lake water (25.04% for Cr(VI) and 20.5% for F-) because of competing ion effect. Mechanism was well established by the kinetic study as well as XPS analysis. Because of high adsorption efficiency, HA@CeO2 NPs can be used for the removal of other harmful water contaminants to make healthy aquatic life as well as purified drinking water.

Solvothermal synthesis of 3D rod-shaped Ti/Al/Cr nano-oxide for photodegradation of wastewater micropollutants under sunlight: a green way to achieve SDG:6.

Waterbodies are day-by-day polluted by the various colored micropollutants, e.g., azo dyes enriched (carcinogenic, non-biodegradable) colored wastewater from textile industries. Water pollution has become a serious global issue as ~ 25% of health diseases are prompted by pollution as reported by WHO. Around 1 billion people will face water scarcity by 2025 and this water crisis is also a prime focus to the UNs' sustainable development goal 6 (SDG6: clean water and sanitation). To prevent the water pollution caused by micropollutants, a mesoporous, 3D rod-like nano-oxide Ti/Al/Cr (abbreviated as TAC) has been synthesized via the solvothermal method. TAC degraded all classes of azo dyes (mono, di, tri, etc.) with > 90% efficiency under renewable energy source solar irradiation within the pH range 2-11. The detailed study was done on the photodegradation of carcinogenic di-azo dye Congo red (CR) which is banned in many countries. TAC showed 90.64 ± 2% degradation efficiency for CR at pH 7. The proposed photodegradation mechanism of CR was confirmed by the high-resolution liquid chromatography-mass spectroscopy (HRLC-MS) analysis obeying the Pirkanniemi path. The photodegradation obeyed the pseudo-1st-order kinetics and was reusable up to successive 5 cycles which can be an efficient tool to meet the UNs' SDG:6.

3D flower-like zirconium magnesium oxide nanocomposite for efficient fluoride removal.

A 3D flower-shaped bimetallic nanocomposite zirconium magnesium oxide (ZMO) was prepared first time by the controlled solution combustion method using triethanolamine (TEA) as a fuel and chelating agent. The composite material was used to remove excess fluoride via adsorption. The thermal stability of the adsorbent was characterized by thermogravimetric analysis (TGA). Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) were used to characterize the adsorbent. The surface charge of the nano adsorbent was determined by Zeta Sizer. The surface area and pore volume of the adsorbent were determined by Brunauer-Emmett-Teller (BET) isotherm and Barrett-Joyner-Halenda (BJH) methods. The adsorption behavior of fluoride was studied systematically varying the pH, contact time, adsorbent dose, and initial fluoride concentration. The adsorption followed the Langmuir isotherm model with a maximum adsorption capacity of 42.14 mg/g. The pseudo-second-order kinetic model was confirmed by the adsorption study. The maximum adsorption efficiency was in the 6-10 pH range. The reaction mechanism was mainly based on ion exchange between hydroxy and fluoride ions which was proven by X-ray photoelectron spectroscopy (XPS). Real water tests indicated that ZMO could be used as a potential defluoridation agent for fluoride containing groundwater treatment.

"Clickable", trifunctional magnetite nanoparticles and their chemoselective biofunctionalization.

A multifunctional iron oxide based nanoformulation for combined cancer-targeted therapy and multimodal imaging has been meticulously designed and synthesized using a chemoselective ligation approach. Novel superparamagnetic magnetite nanoparticles simultaneously functionalized with amine, carboxyl, and azide groups were fabricated through a sequence of stoichiometrically controllable partial succinylation and Cu (II) catalyzed diazo transfer on the reactive amine termini of 2-aminoethylphosphonate grafted magnetite nanoparticles (MNPs). Functional moieties associated with MNP surface were chemoselectively conjugated with rhodamine B isothiocyanate (RITC), propargyl folate (FA), and paclitaxel (PTX) via tandem nucleophic addition of amine to isothithiocyanates, Cu (I) catalyzed azide--alkyne click chemistry and carbodiimide-promoted esterification. An extensive in vitro study established that the bioactives chemoselectively appended to the magnetite core bequeathed multifunctionality to the nanoparticles without any loss of activity of the functional molecules. Multifunctional nanoparticles, developed in the course of the study, could selectively target and induce apoptosis to folate-receptor (FR) overexpressing cancer cells with enhanced efficacy as compared to the free drug. In addition, the dual optical and magnetic properties of the synthesized nanoparticles aided in the real-time tracking of their intracellular pathways also as apoptotic events through dual fluorescence and MR-based imaging.

Highly biocompatible and water-dispersible, amine functionalized magnetite nanoparticles, prepared by a low temperature, air-assisted polyol process: a new platform for bio-separation and diagnostics.

A low temperature polyol process, based on glycolaldehyde mediated partial reduction of FeCl(3).6H(2)O at 120 degrees C in the presence of sodium acetate as an alkali source and 2, 2(')-(ethylenedioxy)-bis-(ethylamine) as an electrostatic stabilizer has been used for the gram-scale preparation of biocompatible, water-dispersible, amine functionalized magnetite nanoparticles (MNPs) with an average diameter of 6 +/- 0.75 nm. With a reasonably high magnetization (37.8 e.m.u.) and amine groups on the outer surface of the nanoparticles, we demonstrated the magnetic separation and concentration implications of these ultrasmall particles in immunoassay. MRI studies indicated that these nanoparticles had the desired relaxivity for T(2) contrast enhancement in vivo. In vitro biocompatibility, cell uptake and MR imaging studies established that these nanoparticles were safe in clinical dosages and by virtue of their ultrasmall sizes and positively charged surfaces could be easily internalized by cancer cells. All these positive attributes make these functional nanoparticles a promising platform for further in vitro and in vivo evaluations.

Biofunctionalized, phosphonate-grafted, ultrasmall iron oxide nanoparticles for combined targeted cancer therapy and multimodal imaging.

A novel, inexpensive biofunctionalization approach is adopted to develop a multimodal and theranostic nanoagent, which combines cancer-targeted magnetic resonance/optical imaging and pH-sensitive drug release into one system. This multifunctional nanosystem, based on an ultrasmall superparamagnetic iron oxide (USPIO) nanocore, is modified with a hydrophilic, biocompatible, and biodegradable coating of N-phosphonomethyl iminodiacetic acid (PMIDA). Using appropriate spacers, functional molecules, such as rhodamine B isothiocyanate, folic acid, and methotrexate, are coupled to the amine-derivatized USPIO-PMIDA support with the aim of endowing simultaneous targeting, imaging, and intracellular drug-delivering capability. For the first time, phosphonic acid chemistry is successfully exploited to develop a stealth, multifunctional nanoprobe that can selectively target, detect, and kill cancer cells overexpressing the folate receptor, while allowing real-time monitoring of tumor response to drug treatment through dual-modal fluorescence and magnetic resonance imaging.

Efficient Fluoride Removal and Dye Degradation of Contaminated Water Using Fe/Al/Ti Oxide Nanocomposite.

The trimetallic Fe/Al/Ti (1:1:1) nanocomposite (FAT), synthesized by an adaptable tuned chemical route, offers a new approach for water treatment, for example, the de-fluoridation and photodegradation soluble dye methylene blue (MB) at pH 7. FAT acted as a good fluoride scavenger in the presence of other co-ions and within a widespread pH range (pH 2-11). The photodegradation efficiencies were >90% for different concentrations of MB solutions. The characterization of FAT includes thermogravimetric analysis, X-ray diffraction, Fourier transform-infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and ζ-potential analysis. Furthermore, the regeneration efficiencies of both the water treatments were checked, where the removal efficiency was not hampered significantly even after five batches. Spectroscopic techniques were adopted to perform the kinetic studies and to propose the probable mechanistic paths.