Journal of Water and Environmental Nanotechnology
Volume:5 Issue: 1, Winter 2020

In this paper, Fe3O4 and MgFe2O4 as magnetic samples were successfully synthesized by coprecipitation and combustion methods, respectively, to be used for adsorption of toxic methyl orange molecules from the aqueous solution. Characteristics of the synthesized samples were evaluated using various analyses. The results of crystalline and surface bonding assessment confirmed the successful synthesis of both samples with an appropriate structure. Moreover, Fe3O4 presented higher magnetic properties and surface area as well as lower pore diameter than MgFe2O4 sample. However, the maximum adsorption of methyl orange was obtained for MgFe2O4 (56.54 mg/g) which was around three times of Fe3O4 in the same conditions. This may be related to larger pore diameter of MgFe2O4 and the ease of access to the internal surface of the adsorbent by the adsorbate molecules. Among the evaluated isotherms, the predicted Freundlich model showed well correlation with actual results of the adsorption process and the process could kinetically explained by the pseudo-second-order equation. Thermodynamic investigation of the process showed the adsorption of methyl orange was exothermic and spontaneous. The results revealed that MgFe2O4 sample (qmax = 181.34 mg/g) can be suggested as a good adsorbent for the removal of toxic dyes and water pollutants.

A three component nanocomposite Poly(O-Toluidine) Zr(IV) based ion exchangers are synthesized by sol-gel method and characterized by Fourier transform-infrared spectra, , X-ray diffraction, scanning electron microscopy, thermo gravimetric analysis, ion exchange studies, conductivity and antimicrobial studies. The organic polymeric part of the composites provides mechanical and chemical stability whereas the inorganic part supports the ion-exchange behavior, thermal stability and also increases the electrical conductivity due to the good ion-exchange behavior of Zirconium (IV) molybdophosphate and Zirconium(IV) iodovanadate . The nano composite of POT/ Zr(IV) Zirconium(IV) iodovanadate exhibited an excellent ion exchange capacity value for Na+ is 4.84 meq g −1 and POT/Zr(IV) molybdo phosphate ion-exchanger has the value 4.60 meq/g . While compared to other nanocomposite ion-exchangers both the ion–exchangers have significant and effective ion-exchange behaviour . From the sorption studies and the distribution coefficient values , both the composite ion exchangers show maximum selectivity towards Pb2+.They can conjugate the mechanical properties of the organic polymers with intrinsic properties of the inorganic ion exchangers creating a new class of hybrid organic – inorganic materials with improvement in thermal stability and good electrical conductivity, ion – exchange capacity and also showed higher antimicrobial activity against Gram positive and Gram negative bacteria like Escherchia coli, Pseudomonas and Staphylococcus saprophitocus, which leads to their usage for environmental remediation like water purification.POT/Zr(IV) molybdophosphate and POT/Zr(IV) iodovanadate nanocomposite ion exchangers were used as promising ion exchangers and applied as electrochemically switchable ion exchanger for water treatment, especially water softening

This paper investigated boron nitride nanocage performance as an adsorbent and sensing material for removal and detection of trinitroanisole by density functional theory. The calculated adsorption energies, Gibbs free energy changes (ΔGad), adsorption enthalpy changes (ΔHad) and thermodynamic equilibrium constants (Kth) revealed the adsorption process is experimentally feasible, spontaneous, exothermic and Irreversible. The highly negative adsorption energy values and bond lengths between B12N12 and trinitroanisole indicated the interaction between the adsorbate and the adsorbent is a chemisorption process. The N-O and C-N bond lengths and the density values showed that trinitroanisole complexes with boron nitride cage have higher explosive velocity and detonation pressure than the pure trinitroanisole without B12N12. The frontier molecular orbital parameters such as band gap, chemical hardness, electrophilicity, chemical potential and charge capacity were also studied and the findings proved B12N12 is an excellent sensing material for fabricating novel electrochemical and thermal sensors for detection of trinitroanisole.

A simple and eco-friendly method for synthesis nanoparticles is using a green chemistry technique. Also, the utilization of green nanoparticles for the treatment of industrial wastewater could be an outstanding plan to confront environmental pollutions. The novelty of this study was to use leaf extract of Stevia Rebaudiana Bertoni for green synthesized TiO₂ NPs and assessing its functioning for the photocatalytic treatment of Naphthol from real sample wastewater in a self-designed photoreactor. The amount of nano-adsorbent changes was studied under different conditions such as the amount of naphthol concentration, pH, and time period of degradation. The results of the XRD showed that the Anatase and Rutile phase of TiO₂ conformed to cards no.JCPDS21-1272 and no.JCPDS21-1276 respectively. The EDX analysis illustrated the existence of TiO₂ with a weight percentage of 50.17 wt.% for Ti and 49/83 for O. The size of the particles in the SEM photo was found to be about 17nm. The removal of naphthol content was measured by the UV-Vis method. The optimum pH for naphthol removal by TiO₂ is pH = 9, the optimal contact time is 20 min, and the optimal concentration of Naphthol is 3 mg/L. Comparing the Freundlich and Langmuir adsorption isotherm models revealed that the absorption model in this study is in complete conformity with the Freundlich adsorption model. This study affirms that the green synthesis of Stevia leaf extracted is a modern beneficial procedure for the preparation of TiO₂ nanoparticles. This method is straightforward, cost-effective, eco-friendly, and rapid.

In the present study, adsorption behavior of mesoporous molecularly imprinted polymers for bisphenol A was investigated. Molecularly imprinted nanopolymers were synthesized by precipitation polymerization using bisphenol A as a template molecule. Two molecular ratios of templet: functional monomer: cross-linker (1:6:30 (MIP-6) and 1:4:20 (MIP-4)) was considered for experiments. Ethylene Glycol Dimethacrylate (EGDMA) as a Crosslinker, metacrylic acid (MAA) as a functional monomer and 2, 2´-azobisisobutyronitrile (AIBN) as an initiator were used for the synthesis of polymers. In addition, Langmuir and Freundlich adsorption isotherms and pseudo-first-order and pseudo-second-order kinetic models were studied for adsorption mechanism. Results showed that porous polymers with average pore diameter of 13 to 17 nm and specific surface area of 326 to 439 (cm3/g) were obtained. The maximum adsorption capacity was 400.1 μmol/g for MIP-6. SEM analysis showed that the synthesized polymer particles were spherical. The highest adsorption efficiency of bisphenol A achieved by MIP-6 was 71%.

The aim of this project is the production of The Descurainia Sophia adsorbent in nano dimensions using a super-grinding disk mill. The top-down method was used in the process of nanogel preparation. After complete drying of the stems, the stems were reduced to smaller sizes by an electric mill, and by using the available sieve to standard number 60, adsorbent granulation was performed. The adsorbent was used to remove copper from aqueous solution. The tests and their optimization results were based on the design of experiments in three levels of variables using Taguchi method. According to the experiment results, pH, contact time, and adsorption mass are the main factors and the most influential effect on the removal of copper from the aqueous solution is the pH parameter, which has a lower p-value. As the pH increases from 5 to 9, the efficiency of copper metal removal increases. The concentration of hydrogen ions is the most important parameter affecting the adsorption process. The effect of temperature on adsorption efficiency has been investigated in the range of 20-50°C. Finally, the highest efficiency of copper cation removal was at 30°C and 8.89%. The results showed that the pH of the solution had the most effect on the copper removal efficiency and in the playing environment, the effect of copper removal was more than the acid and neutral conditions of the solution. Also, the adsorbent mass and contact time have the most effect on copper removal after the pH parameter in the Taguchi method.

Nanotechnology is getting an incredible drive due to the potential of manipulating metals into their nano size particles. The synthesis and characterization of nano particles using green technology have many applications. The wet chemical techniques used presently in the synthesis of nano particles are deleterious along with flammable conditions. Silver nanoparticles have the capability of killing microbes in an effective manner. This paper explains about the green technology and pollution free methodology for synthesizing silver particles at nano scale using 1mM silver nitrate solution from the extracts of Carica papaya, Emblica officianalis, Azadirachta indica and Cocos nucifera. When the silver nanoparticles are synthesized the solution turns to brownish yellow colour. The tools used in the characterisation of silver nano particles are Ultra Violet - Visible absorption Spectroscopy and Field Emission Scanning Electron Microscopy. The solutions with silver nanoparticles showed the maximum absorption at 450 nm with Ultra Violet - Visible spectroscopy. It is found that C. Papaya and E. oficianalis showed the maximum absorbance of 0.578 and 0.59 respectively at 450 nm. The average range of the produced silver nano particles are analysed to be 5 – 70 nm with FESEM and the shape is examined to be spherical.

The present paper was depicted to analyze the water quality status in single terms and zooplanktons of the Bhagirathi river. The water quality parameters were analyzed in lab.such as pH, Total Dissolved Solid (TDS), Total Hardness (TH), Chloride, Dissolved Oxygen, Calcium , Biochemical Oxygen Demand (BOD and Chloride. In the I site of the first area , the value of WQI in monsoon 55.79, winter 31.73 and summer 45.66, In the site 2, the value of WQI in monsoon 61.46 ,winter 38.17and summer 46.42 , In the site 3 ,the value of WQI in monsoon 61.36 , winter 32.91 and summer 47.55 were observed. Water quality index in the all study site is good in winter and summer, but poor in monsoon season. These fresh water systems also support various forms of aquatic life. The zooplankton of our study site mainly comprised of Protozoa, Rotifer, Copepoda and Cladocera. A total of 11 genera of Zooplanktons were observed during the course of study. The maximum number of Zooplanktons genera was during winter and minimum during rainy season. The most remarkable aspect of River Bhagirathi at these sites seems to be the tremendous potential to heal the health of entire river ecology that get damaged due to insufficient water released from the hydro-electric power project after dam wall into the main river channel .Immediate steps need to be taken in order to restore the ecological balance – mainly in main river channels after the dam wall of hydro-electric power projects.