Metal Organic Frameworks (MOFs) are widely employed as catalysts and semiconductors due to unique combination of crystalline and porous structure. The presence of polar and non-polar groups on organic linkers provides extra coordination sites for attachment of various metals. The topology of single and mixed organic ligands is tuned to higher surface area and increased porosity likely to serve as good adsorbents. The present study is based on synthesis of single and mixed ligand MOFs with Nickel as precursor. Oxalic and trimesic acid, representatives of di- and tri- carboxylates provides the organic framework. The characterization of synthesized MOFs by FTIR, XRD and SEM/EDX techniques reveal average crystallite size (0.2-3nm) and Ni is incorporated to mass percentage of 9-13%. Ni-O binding is exhibited at FTIR frequency of 493-500cm-1. The application of synthesized MOFs in batch experiment at varying adsorbent dose, concentration and temperature demonstrated adsorptive capacity for Polyaromatic hydrocarbons in the sequence dibenzofuran (81%) > phenanthrene (91%) > anthracene (33%). The adsorbents were also proven to be effective for removal of pollutants from industrial waste with average percent removal of 73% for incinerator ash. The study concluded that use of synthesized MOFs as an adsorbent for removal of pollutants is most effective way for environmental remediation. These MOFs can also be applied for catalysis of toxic environmental pollutants.
Environment is confronted with a variety of natural and synthetic organic compounds in its compartments, following rapid industrialization and urbanization. These continuously growing challenges elevate the need for implementing the clean and cost effective technologies. The plan of the present investigation is the copolymerization of natural and synthetic materials for the development of adsorbents followed by its application for the removal of environmental pollutants. Starch is selected as natural biopolymer and cyclodextrin represents the synthetic polymer. Both materials are copolymerized and further modified with the Cabbage fibres and epichlorohydrin as cross linker. FTIR analysis reveals the presence of cyclodextrin in the synthesized copolymer through stretching vibration of -CH2, -C-O-C at 2931cm-1 and 1016cm-1, respectively. On the other hand, starch based copolymer cross linked with epichlorohydrin is identified by the absorption band of epoxy group at 931cm-1. The presence of terminal and internal epoxy group at 763cm-1 and 669cm-1 also supports the synthesis. The SEM illustrated wider cavities that are expected to enhance the uptake capacity of modified copolymers for organic moieties. The inclusion complex of β-Cyclodextrin depicts rectangular features with milky white surface. The samples were scanned 10-71 of 2θ by steps of 0.015 with Cu K α radiation (λ = 1.54059) operating at 40 kv and 100 mA. The synthesized Copolymers were applied as adsorbents in a batch experiment to determine efficiency for the removal of a wide range of environmental pollutants. The results of UV-Vis disclosed that crystal violet and congo red is removed to a comparable extent. Atomic absorption analysed the Lead (85-95%) is more efficiently removed than Chromium (60-70%). It might be related to higher molecular weight of the former than the later. Similarly, the fused aromatic rings demonstrated less removal for pyrene (202.25g/mol) than anthracene (178.23g/mol). The synthesized copolymers were also applied for the adsorption of PCBs from transformer oil to present model of in-situ remediation.