Lead adsorption and antibacterial activity using modified magnetic biochar/sodium alginate nanocomposite.

Biochar is one of the most promising wastewater treatment materials. As shown in the Scanning Electron Micrograph, the magnetic biochar (BC) cross-linked glutaraldehyde (G) with sodium alginate (SA) (BC-G-SA) nanocomposite formed with uniform particle size without aggregation, and an X-Ray Diffraction study revealed that the BC-G-SA nanocomposite has an amorphous structure. The BC-G-SA nanocomposite enhanced the microwave adsorption process for Pb (II). The maximum metal capacity value was obtained using the microwave adsorption technique at pH 5.0 and contact time 20 s for Pb (II) at medium and low microwave power (940 and 1400 µmol g-1, respectively). Pb (II) adsorption isotherm follows a pseudo-second-order model. Also, the BC-G-SA nanocomposite effectively inhibited bacterial growth throughout the growth kinetics experiment. BC-G-SA inhibited the growth of S. aureus at a MIC of 200 g mL-1, whereas L. monocytogenes had a MIC of 200 g mL-1. The MIC values for E. faecalis and E. faecium were significantly lower (50 and 100 g mL-1, respectively).

Fabricated and functionalized magnetite/phenylenediamine/cellulose acetate nanocomposite for adsorptive removal of methylene blue.

The industrial revolution in textile and dying process is moving with huge steps, but the treatment of produced wastewater from this industry is a huge dilemma. This work demonstrates the preparation and utilization of cellulose acetate (CA) blended with Fe3O4 already chemically modified with O-phenylenediamine (PDA) to prepare a novel magnetic Fe3O4/PDA/CA nanocomposite. This nanomaterial was aimed to use in the removal of methylene blue (MB) dye from water. The adsorption process was conducted using a batch technique and the removal process was evaluated under various experimental conditions. From this study, it was found that the values were increased from 55.8% to 88.54%, 45.5% to 84.8% and 42.56% to 76.45% by the increase of from pH 1 to 7, respectively using 10, 50 and 100 mg·L-1. The pseudo-second-order was found to be the most fitted model to confirm that the adsorption reaction is related to a chemisorption process between the Fe3O4/PDA/CA nanocomposite and MB dye. The Langmuir and Freundlich models were also found to best-fitted models to reveal the formation of monolayer and multilayer of MB over Fe3O4/PDA/CA nanocomposite in a chemical process. The thermodynamic parameters confirm that this type of reaction is spontaneous and exothermic reaction.

Assessment of heat-inactivated marine Aspergillus flavus as a novel biosorbent for removal of Cd(II), Hg(II), and Pb(II) from water.

A novel marine fungus was isolated and classified as Aspergillus flavus strain EGY11. The heat-inactivated form of isolated Aspergillus flavus was investigated and evaluated as a new eco-friendly and highly efficient biosorbent for removal of toxic heavy metals such as Cd(II), Hg(II), and Pb(II) from aqueous solutions. The SEM morphological studies of biosorbent-loaded metal ions confirmed their direct binding on the surface of heat-inactivated Aspergillus flavus. The metal biosorption capacity values were determined and optimized by the batch technique in the presence of various experimental controlling factors such as pH, contact time, biosorbent dosage, initial metal ion concentration, and coexisting species. The maximum metal capacity values of Cd(II), Hg(II), and Pb(II) were cauterized as 1550 (pH 7.0), 950 (pH 7.0), and 1000 µmol g-1 (pH 6.0), respectively. The equilibrium time for removal of metal ions was identified as 40 min. The maximum sorption capacity values (1200.0-4000.0 µmol g-1) were established by 5.0 mg as the optimum mass of biosorbent. The collected biosorption data obtained from the equilibrium studies using the initial metal ion concentration were described by the Langmuir, Freundlich, Brunauer-Emmett-Teller (BET), and Dubinin-Radushkevich isotherm (D-R) isotherm models. The potential implementation of heat-inactivated Aspergillus flavus biosorbent for heavy metal removal from different water samples was successfully accomplished using multistage microcolumn technique. The results refer to excellent percentage recovery values in the ranges 92.7-99.0, 91.3-95.6, and 95.3-98.2% for the biosorptive removal of Cd(II), Hg(II), and Pb(II), respectively, from the examined environmental samples.