A novel branched polyamine (polyethyleneimine, PEI) functionalized mesoporous silica (MS) adsorbent is developed via a facile "grafting-to" approach. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy verified the effective surface functionalization of MS with monolayer and polymer. The transmission electron microscopy (TEM) was employed to reveal the morphology of the fabricated materials. The adsorption behavior of the polyamine functionalized mesoporous silica (MS-PEI) is assessed against anionic dyes. The adsorbent characteristics of MS-PEI are compared with a monolayer platform comprising of 3-aminopropyltriethoxy silane (APTES) functionalized mesoporous silica (MS-APTES). The adsorption behavior of the MS-PEI and MS-APTES toward anionic dyes is further evaluated by studying the effect of adsorbent dosage, pH, contact time, and temperature. Langmuir and Freundlich isotherm models are employed to understand the adsorption mechanism. The obtained kinetic data support a pseudo-second-order adsorption behavior for both monolayer and polymer functionalized MS. The associated thermodynamic parameters (ΔG°, ΔH°, and ΔS°) reveal that the process of adsorption with MS-PEI is more spontaneous and energetically favored as compared to the adsorption with MS-APTES. Taken together, the novel adsorbent system derived from a combination of MS and branched polymer (MS-PEI) shows the higher absorption efficiency and capacity toward the anionic dyes than the monolayer based adsorbent (MS-APTES).

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Levels of selected metals Na, Ca, Mg, K, Fe, Mn, Cr, Co, Ni, Cd, Pb and Mn were estimated by flame atomic absorption spectrophotometry in groundwater samples from Kasur, a significant industrial city of Pakistan. Salient mean concentration levels were recorded for: Na (211 mg/l), Ca (187 mg/l), Mg (122 mg/l), K (87.7 mg/l), Fe (2.57 mg/l) and Cr (2.12 mg/l). Overall, the decreasing metal concentration order was: Na>Ca>Mg>K>Fe>Cr>Zn>Co>Pb>Mn>Ni>Cd. Significantly positive correlations were found between Na-Cr (r=0.553), Na-Mn (r=0.543), Mg-Fe (r=0.519), Mg-Cr (r=0.535), Pb-K (r=0.506) and Pb-Ni (r=0.611). Principal Component Analysis and Cluster Analysis identified tannery effluents as the main source of metal contamination of the groundwater. The present metal data showed that Cr, Pb and Fe levels were several times higher than those recommended for water quality by WHO, US-EPA, EU and Japan. The elevated levels of Cr, recorded as 21-42 fold higher compared with the recommended quality values, were believed to originate from the tanning industry of Kasur.

Levels of 10 metals (Ca, Mg, Fe, Zn, Cu, Mn, Cd, Co, Cr and Ni) in the scalp hair of male and female donors, with age groups between 3 and 100 years, were determined by ICP-AES. In total, 58 male and 30 female hair samples were analyzed in triplicate. The donors belonged to the rural area of district Chakwal, a well-known typical non-urban site in Pakistan. Calcium showed the highest concentration of 462 microg/g in the hair of males and 870 microg/g in those of females followed by Zn, at 208 and 251 microg/g for the two sexes. For male donors, Cd showed the lowest concentration (1.15 microg/g) while for female donors Co remained at minimum level (0.92 microg/g). The order of decreasing metal concentration in the hair of male donors was: Ca > Zn > Mg > Fe > Cu > Mn > Ni > Cr > Co > Cd while that for female donors it was: Ca > Zn > Mg > Fe > Cu > Mn > Cr > Ni > Cd > Co. The female group exhibited enhanced levels of all selected metals except Fe and Co in their hair as compared with the male counterparts. A strong bivariate positive correlation was found between Fe and Zn (r = 0.841) for the hair samples from male category while for the female category, strong positive correlations were observed between Ca-Mg (r = 0.617), Ca-Zn (r = 0.569), Ca-Mn (r = 0.565), Mg-Mn (r = 0.655), Cr-Cu (r = 0.655) and Cr-Ni (r = 0.685). The distribution of metals in the hair of donors with respect to different age groups was also investigated for both genders. The study showed that in case of males, the concentration of all selected metals decreased with increasing age except for Cu, Co and Cr. However, for females the hair metal levels increased with age, except for Co for which the concentration decreased with age. No appreciable change in the metal concentration was observed as a function of age for the combined sexes.