Removal of humic acid from peat water using untreated powdered eggshell as a low cost adsorbent

The main objective of this study is to investigate the possibility of powdered eggshell used as an adsorbent material for removal of humic acid from peat water. The influences of contact time, dose of eggshells, pH, and temperature were the factors considered in the removal processes of humic acid from peat water. In addition, adsorption isotherms of humic acid onto the powdered eggshell were also evaluated with the Langmuir and Freundlich approximations. Our results showed that the equilibrium of the process was eventually established after 60 min of the contact time, and also found that using 5 g of the powdered eggshell nearly 95 % of humic acid has been successfully removed from the peat water. The removal of humic acid gave better result when it was conducted at low pH, and it was almost unaffected the temperatures variation. The data was well fitted to Freundlich isotherm with the correlation coefficient of not <0.999, and could uptake the humic acid about 126.58 mg/g at pH 4.01, estimated from the Langmuir model. The kinetic experimental data proportionally correlated with the pseudo-second-order kinetic model with a rate constant in the range of 0.016-0.112 g mg -1 min -1 , while intra-particle-diffusion were the main rate determining step in the humic acid removal process. The powdered eggshell investigated in this study, thus, exhibited as a high potential adsorbent for the removal of humic acid from peat water

Pharmacologically active flavonoids from the anticancer, antioxidant and antimicrobial extracts of Cassia angustifolia Vahl

Background: Cassia angustifolia Vahl. (commonly known as senna makkai or cassia senna), native to Saudi Arabia, Egypt, Yemen and also extensively cultivated in Pakistan, is a medicinal herb used traditionally to cure number of diseases like liver diseases, constipation, typhoid, cholera etc. This study was conducted to evaluate the in-vitro antimicrobial, antioxidant and anticancer assays and phytochemical constituents of aqueous and organic extracts of C. angustifolia leaves. Methods: The antimicrobial activities of C. angustifolia aqueous and organic (methanol, ethanol, acetone, ethyl acetate) extracts were investigated by the disk diffusion method. These extracts were further evaluated for antioxidant potential by the DPPH radical scavenging assay. Anticancer activities of the extracts were determined by the MTT colorimetric assay. The total phenolic and flavonoid contents of C. angustifolia extracts were evaluated by the Folin-Ciocalteu method and aluminum chloride colorimetric assay, respectively. The structures of the bioactive compounds were elucidated by NMR and ESI-MS spectrometry. Results: Bioactivity-guided screening of C. angustifolia extracts, led to the isolation and identification of three flavonoids quercimeritrin (1), scutellarein (2), and rutin (3) reported for the first time from this plant, showed significant anticancer activity against MCF-7 (IC50, 4.0 mu g/mu L), HeLa (IC50, 5.45 mu g/mu L), Hep2 (IC50, 7.28 mu g/mu L) and low cytotoxicity against HCEC (IC50, 21.09 mu g/mu L). Significant antioxidant activity was observed with IC50 2.41 mu g/mL against DPPH radical. Moreover, C. angustifolia extracts have the potential to inhibit microbial growth of E. cloacae, P. aeruginosa, S. mercescens and S. typhi. Conclusion: C. angustifolia extracts revealed the presence of quercimeritrin (1), scutellarein (2), and rutin (3), all known to have useful bioactivities including antimicrobial, antioxidant and anticancer activities.Research Directorate, National University of Sciences and Technology (NUST), Islamabad, Pakistan [H-12]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]