Megh Raj Pokhrel

Adsorption of Cd (II), Cu (II), and Zn (II) from Aqueous Solution onto Nitrogen-Functionalized Desmostachya bipinnata

A very simple means of nitrogen functional group grafting onto the backbone of Desmostachya bipinnata is investigated, which is a sacrificial herb in the south Asian region particular to Hindu religion. This natural biomaterial is found to be very effective for metal binding, after treatment with hydrazine monohydrate. The present study explores a comparison of amination processes by considering several options. The maximum metal loading capacities for Cd, Cu, and Zn were found to be 76.80 mg/g, 72.10 mg/g, and 58.16 mg/g, respectively. The kinetic evaluation indicated that the adsorption of Cd, Cu, and Zn onto the biomaterials followed the pseudo second-order rate equation.

Adsorptive Removal of Methyl Red from Aqueous Solution onto Charred and Aminated Sugarcane Waste

Abstract: Adsorptive removal of Methyl Red (MR) from aqueous solution onto chemically modified charred sugarcane waste (CSW) and aminated sugarcane waste (ASW) has been investigated. The surface modification was characterized by FTIR, SEM, elemental analysis and Boehm titration. The effect of pH, contact time and MR concentrations were studied by batch equilibrium method. Maximum dye removal was observed at pH 2 onto CSW while that for ASW at pH 7. The dye can be quantitatively removed onto the surface of these adsorbents at a contact time of 3 h. Maximum adsorption capacity (q max ) for the CSW and ASW were found to be 125.0 mg/g and 142.85 mg/g, respectively. Adsorption kinetic data were tested using pseudo-first order, pseudo-second order and intra-particle diffusion models. Kinetic studies revealed that the adsorptive removal of the dye onto the adsorbents followed pseudo-second order kinetics model. The obtained results indicated an excellent alternative for the treatment of dye contaminated wastewater using such chemically modified sugarcane waste at low cost with better efficiency. Â

Experimental Strategies Toward the Use of the Porin MspA as a Nanotemplate and for Biosensors

The porin MspA from Mycobacterium smegmatis has many unique properties, one being that it is the longest and the most stable porin identified to date. It is formed by supramolecular interaction of eight identical monomers of 184 amino acid residues (m = 20,000 Da). With dimensions of approx 10 nm in length and a diameter ranging from 1 nm (constriction zone) to 4.8 nm (opening of the MspA-goblet), it is ideal for bio-nanotechnological applications. The porin possesses a hydrophobic “docking zone,” which enables it to reconstitute not only in lipid membranes, but also in numerous artificial (mono)membranes and hydrophobic, water-soluble polymer layers. Furthermore, we demonstrate here the design and proof-of-principle of an MspA porin-based biosensor for the TB-antibiotic isoniazid.