Assessment of heavy metals concentrations in the soil of Mongla industrial area, Bangladesh

Background: Contamination of soil with heavy metals is an alarming issue around the world. Therefore, this study aimed to assess the contamination status of heavy metals in the soil of Mongla industrial area, Bangladesh. Methods: Soil samples were randomly collected from 20 sites and digested by wet digestion method. The concentrations of heavy metals (Mn, Fe, Cu, Zn, Cd, and Pb) were determined using atomic absorption spectrophotometer (AAS). The quality of soil was assessed based on the contamination factor (CF), geoaccumulation index (Igeo), enrichment factor (EF), and ecological risk index factor (ERIF) analyses. Results: The average concentrations of Mn, Fe, Cu, Zn, Cd, and Pb were obtained to be 258.08 ± 51.61, 3736.90 ± 322.17, 19.55 ± 6.49, 66.76 ± 18.32, 0.59 ± 0.13, and 10.40 ± 1.49 mg kg-1, respectively, which were below the permissible limit. The highest value of CF (0.74 ± 0.16), Igeo (0.35 ± 0.34), EF (24.86 ± 6.27), and PERIF (22.11 ± 4.81) was observed for Cd. The pollution of CF, Igeo, EF, and ERIF was classified as very severely polluted, unpolluted to moderately polluted, strongly to extremely polluted, and slightly polluted, respectively, with these heavy metals due to anthropogenic activities. One-way ANOVA indicated a significant difference between Zn and Cd concentrations (P < 0.05), whereas Pearson correlation showed a positive correlation between Zn-Pb (P = 0.01) and Fe-Zn (P = 0.05). Conclusion: There are different classes of contamination with heavy metals in the study area. Therefore, necessary steps should be taken and people’s awareness of the soil pollution should be raised. Keywords: Soil pollution, Heavy metals, Contamination factor, Geoaccumulation index, Enrichment factor, Ecological risk index facto

A review on synthesis, characterizations, and applications of Schiff base functionalized nanoparticles

Nanotechnology has shown a promising future in material science for its enormous applications in the field of analytical, biological, catalytic, electroanalytical fields and so on. Recent nanoscience has given huge effort to enhance the applicability of nanoparticles (NPs) though modification or functionalization process, which makes its more sophisticated than the conventional one. In this modification process, nanoparticles (NPs) are stabilized or factionalized using organic, inorganic, metal complexes, and even with Schiff base (SB) ligands and their metal complexes. Schiff-base ligand functionalized NPs have wide applicability in catalytic process, antioxidant, antifungal, and analytical techniques due to enhancing of interfacial area between SB ligands and nanoparticles. The functionalized NPs have been introduced as a sensor for the detection of minute level of heavy metals, pesticides, and biomolecules. The composite materials have catalytic activities in a myriad number of oxidations, reduction, addition, and synthesis of organic molecules. The results revealed that the catalytic activities of the nano-catalysts remained fairly constant even after using several times in a chemical reaction. Besides, the biological behaviors of the SB functionalized NPs were prominently noticed due to presence of various functional groups, atoms, metal ions as well as nanomaterial. Even, the imine group (>C = N−) of SB effectively interacts with the cell of microorganisms, and inhibits the growth of cell. Schiff base ligands and corresponding metal complexes as enzyme inhibitor and potential antioxidants. So, this review study provides an outline about the applications of Schiff base functionalized NPs in catalysis, analytical, and biological applications