Sorption of Phosphorus, Nickel, and Lead from Aqueous Solution Using Manganese Oxide-Coated Materials

Manganese oxide-coated sand (MOCS) and manganese oxide-coated crushed brick (MOCB) were prepared and characterized and employed for the removal of phosphorus ions (PO4 3−) and Pb(II) and Ni(II) ions from aqueous solution. To study the surface properties of the adsorbents, scanning electron microscopy (SEM), X-ray diffraction (XRD) methods, and BET analyses were used. Adsorption was investigated by batch experiments. The estimated optimum pH was 7 for Ni(II) and 5 for all other ions retention by the two considered adsorbents. Both the Freundlich and Langmuir isotherms provided a reasonable fit to the experimental data for the adsorption. The adsorption capacities of the coated adsorbents at a considered pH value and a temperature of 20°C were 1.96 and 2.08 mg/g for PO4 3−, 2.4 and 3.33 mg/g for Ni(II), and 6 and 6.25 for Pb(II) onto MOCS and MOCB, respectively. The pseudo-first-order and pseudo-second-order equations as well as the intraparticle diffusion model were determined to test the adsorption kinetics and the rate constants derived from the three kinetic models being calculated. The pseudo-second-order kinetic model was better appropriated. Results obtained from this study confirm that the manganese oxide-coated sorbent is considerably considered like suitable for the removal of anions and cations from aqueous solutions

Application of sheep manure and potassium fertilizer to contaminated soil and its effect on zinc, cadmium and lead accumulation by alfalfa plants

In Jebel Ressas mining area (Southern of Tunisia), the dispersion of particles that contain Pb, Zn and Cd results in the contamination of the surrounding agricultural soils. These soils have high concentrations of Pb (970 mg kg−1), Zn (9641 mg kg−1) and Cd (53 mg kg−1). This glasshouse study examined the effect of application of fertilizers, i.e., organic fertilizer as local sheep manure and inorganic fertilizer as potassium chloride (KCl), on the growth, uptake and translocation of Cd, Pb, and Zn of alfalfa (Medicago sativa L.) grown on a contaminated soil. Obtained results showed that alfalfa could tolerate high Cd, Pb, and Zn concentrations in soil and had very good growth performance. Regarding to biomass generation it was observed, in every case, that plant growth is not affected in the treated soil compared with blanks sown in an untreated control soil; improvement ranged from 80% for the KCl to 97% for sheep manure. Application of sheep manure increased electrical conductivity and reduced DTPA-extractable metal concentrations in the soils. But KCl fertilizer favored their accumulation in plants. So, KCl could be a useful amendment for phytoextraction of metals by accumulator species, while sheep manure can be very useful for phytostabilisation