An effective nano-adsorbent has been synthesized by the modification of magnetite nanoparticles with ionic-liquid modified calix[4]arene through covalent linkage. This nanocomposite was used for the removal of amino-functionalized nitrogenous pesticides, metribuzin (MET), and dicloran (DIC) from an aqueous solution through adsorption. The adsorption studies showed that the synthesized nanomaterial was effective in removing these pollutants from an aqueous solution. The maximum adsorption capacity for MET and DIC were 5.88 and 1.94 mg g À 1 , respectively. The effect of various factors, such as dosage, pH, and temperature, were studied on the adsorptive removal of MET and DIC. The adsorption was observed to follow Freundlich isotherm and pseudo-second-order kinetics for MET and DIC. The nano-adsorbent was stable and reusable even after the third cycle. The present studies will lead to the development of an ultimate tool for attempting to the problem of water pollution.

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Manganese and cobalt complexes have been designed and prepared with a tetradentate ligand i.e. isopthalic acid-bis(thiosemicarbozone) (IPBT), which bind to metal ions via donor atoms present in ligand. Different spectroscopic techniques viz. nuclear magnetic resonance, infra red, mass, electronic spin resonance and analytical studies have been used to determine the chemical composition of synthesized IPBT and its Mn(II) and Co(II) complexes. The spectroscopic data exposed that IPBT behaves in a tetradentate (N2S2) mode by having ability to bind with metal ions through N2S2 atoms. An octahedral structure for manganese and cobalt complexes has been suggested on the basis of spectroscopic as well as analytical studies. The ligand (IPBT) and its metal(II) complexes have been screened to determine their antipathogenic activity against some selective microorganisms S. aureus, P. aeruginosa, E. coli, A. niger, M. phasolina and P. glomerata. In this experimental work, well diffusion and poisoned food techniques have been introduced for screening purpose and as standard drugs neomycin and chlorothalonil have been used. Data for antipathogenic screening exposed that metal complexes exerted higher activity towards all examined microbes (bacteria and fungi) even than ligand.

The presence of a highly toxic pyridine carboxamide insecticide, namely flonicamid in water bodies poses a serious risk to both the aquatic ecosystem and human health. Therefore, a graphene oxide (GO) decorated with azo‐functionalized calix[4]pyrrole i. e. GO‐azocalix[4]pyrrole (GACP) was synthesized to study the removal of flonicamid insecticide through adsorption. The nano‐adsorbent was characterized by IR, XPS, TGA, Raman, SEM, and TEM data. The effect of concentration of flonicamid solution, contact time, adsorbent dosage, temperature, and pH was investigated in the batch adsorption process. Experimental data suggested that equilibrium was attained within 40 min and adsorption efficiency was 93.28 %. The synergistic effect of GO and azocalix[4]pyrrole played an important role in the adsorption. The Langmuir isotherm was followed and the maximum adsorption capacity was found to be 11.43 mg/g. The pseudo‐second‐order kinetic data was well obeyed and thermodynamic investigation suggested the feasible and spontaneous nature of flonicamid onto GACP nanocomposite.

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