There remains a real need for the easy, eco-friendly and scalable preparation method of graphene due to various potential applications. Chemical reduction is the most versatile method for the large scale production of graphene. Here we report the operating conditions for a one-step, economical and green synthesis method for the reduction of graphene oxide using a biomolecule (alanine). Graphene oxide was produced by the oxidation and exfoliation of natural graphite flake with strong oxidants using Hummers method (Hummers and Offeman, 1958), but the method was revised in our laboratory to set up a safe and environmentally friendly route. The reduction of graphene oxide was investigated using alanine at various operating conditions in order to set up optimum conditions (treatment time, temperature and concentration of the reagent). Samples have been characterized by using UV-Visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction analysis.

The presence of antibiotic molecules in the natural water sources is currently a huge problem due to the development of bacterial resistance. Graphene oxide (GO) has a large potential as a candidate for the applications of water treatment. In this paper, graphene oxide was tested as a new generation adsorbent for the removal of two antibiotics: trimethoprim (TMP) and isoniazid (INH). Both adsorption processes reached the equilibrium in less than 1 h. Maximum adsorption capacities were found to be 204.08 mg g^-1 for TMP and 13.89 mg g^-1 for INH. TMP adsorption on GO was favored in alkaline medium while the performance of GO for INH adsorption was better in acidic conditions.

In this paper, a one-pot and easy-to-handle method at room temperature without additional chemicals for the modification of graphene oxide (GO) with surfactant is found. Removal of nickel (II) ions from aqueous solutions by GO and surfactant (sodium dodecyl sulphate) modified graphene oxide (SDS-GO) was studied spectrophotometrically at room temperature as a function of time, initial concentration and pH. Adsorption capacity of the adsorbent was increased dramatically (from 20.19 to 55.16 mg/g found by Langmuir model) due to the functionalization of the surface by SDS. The driving force of the adsorption of Ni(II) ions is electrostatic attraction and Ni(II) ions adsorbed on the GO surface chemically besides ion exchange.

In the present study, a new organoclay adsorbent for the adsorption of isoniazid (INH) was produced with the modification of bentonite using green chemistry approach. Glycine was used for the modification because of being environmentally friendly and biocompatible. Then the removal of INH was studied in aqueous solutions. Experiments were conducted as a function of contact time, initial concentration and solution pH to understand the adsorption mechanism. The equilibrium time for the adsorption was found as 20 min. Adsorption capacity of the adsorbent was increased from 21.10 mg/g to 33.90 mg/g after modification. The maximum adsorption was observed at pH 1.5. The results showed that INH was physisorbed on the adsorbents with the contribution of π dispersion interactions.

The presence of antibiotic residues in the aquatic environment poses a potential risk to living organisms due to the development of antibiotic resistance in bacteria. In the present study, the removal of isoniazid by commercial powdered activated carbon was studied in aqueous solutions. The adsorption experiments were done as a function of time, concentration, temperature, and pH in order to understand the adsorption mechanism. The Langmuir and the Freundlich isotherms were used to model the equilibrium data. The results showed that isoniazid was physisorbed on the surface of the activated carbon by π–π dispersion interactions.