Efficient removal of heavy metals from polluted water with high selectivity for Hg(ii) and Pb(ii) by a 2-imino-4-thiobiuret chemically modified MIL-125 metal-organic framework.

A highly porous adsorbent based on a metal-organic framework was successfully designed and applied as an innovative adsorbent in the solid phase for the heavy metal removal. MIL-125 was densely decorated by 2-imino-4-thiobiuret functional groups, which generated a green, rapid, and efficacious adsorbent for the uptake of Hg(ii) and Pb(ii) from aqueous solutions. ITB-MIL-125 showed a high adsorption affinity toward mercury(ii) ions of 946.0 mg g-1 due to covalent bond formation with accessible sulfur-based functionality. Different factors were studied, such as the initial concentration, pH, contact time, and competitive ions, under same circumstances at the room temperature. Moreover, the experimental adsorption data were in excellent agreement with the Langmuir adsorption isotherm and pseudo-second order kinetics. At a high concentration of 100 ppm mixture of six metals, ITB-MIL-125 exhibited a high adsorption capacity, reaching more than 82% of Hg(ii) compared to 62%, 30%, 2%, 1.9%, and 1.6% for Pb(ii), Cu(ii), Cd(ii), Ni(ii), and Zn(ii), respectively.

Effect of Echinostoma liei infection on alterations of protein content and some enzymes in Biomphalaria alexandrina snails.

The survival rate and fecundity of B. alexandrina were greatly reduced when exposed to E. liei miracidia. Also, exposure of B. alexandrina snails to E. liei miracidia induced a disruption in the snail metabolism and this effect was more pronounced in 20-days post-miracidial exposure group than in 10-days group. Protein content was significantly reduced in all exposed snail groups than in the control group. A significant elevation in the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes was recorded also in exposed snails than unexposed ones (control snails). The results indicated also that there were significant increases in the levels of acid and alkaline phosphatases enzymes in exposed snails.

Effect of double infection with Schistosoma mansoni and Echinostoma liei on some physiological parameters of Biomphalaria alexandrina.

The survival rate and fecundity of B. alexandrina were greatly influenced when exposed to either S. mansoni or E. liei miracidia. The snails exhibited much lower survival rate and fecundity when double exposed to both S. mansoni and E. liei miracidia than single exposure and control snails. The results indicated a disruption in the snail metabolism due to exposure to S. mansoni and E. liei miracidia and this effect was more pronounced in case of double exposure to the two parasites. Protein concentrations in hemolymph and tissues significantly reduced in all exposed snail groups than in the control group. A significant elevation in the levels of aspartate aminotransferase (ASAT) and alanine aminotransferase (Asat) enzymes was recorded in hemolymph and tissues of exposed snail than unexposed (control snails). The ASAT/ALAT ratios in tissue and hemolymph of single-exposed and unexposed B. alexandrina did not exceed 1, while it increased up to 1.18 in hemolymph of double exposed snails. There were significant increases in the levels of acid and alkaline phosphatases enzymes in exposed snails.