Immobilization of lead by a vermicompost and its effect on white bean (Vigna Sinenis var. Apure) uptake

Abstract

ABSTRACT:Lead is one of the most dangerous contaminants which has been released to the environment during many years by anthropogenic activities. Adsorption of Pb 2+ on vermicompost was studied at 11°C, 30 °C and 50 °C by using Langmuir and Freundlich models, that adequately described the adsorption process, with maximum adsorption capacities were 116.3; 113.6 and 123.5 µg/g for each temperature. The differences in FTIR (Fourier Transform Infrared Spectrometer) spectra of vermicompost at pH 3,8 and pH 7.0 in the region from 1800 to 1300 cm -1 were interpreted on the basis of carboxyl acid ionization that reduce band intensity around 1725 cm -1 producing signals at 1550 cm -1 (υ a ) and 1390 cm -1 (υ a ) of carboxylate groups. Similar changes were detected at pH 3.8 when ionic lead was present suggesting that heavy metal complexation occurs throughout a cationic exchange reaction. Vermicompost was applied to a soil where white bean plants were planted. After irrigation with lead nitrate solutions the uptake of lead was reduced to 81 % in leaves and stem, while the reduction in the roots was around 50 %. The highest accumulation of lead was found in the roots and the translocations seems to be limited by the presence off vermicompost in the soil.

Comparison of heavy metals content in compost against vermicompost of organic solid waste: Past and present

“…Thus, metal mobility may be both qualitatively and quantitatively different in fresh earthworm casts compared with mature, equilibrated vermicomposts. The significantly reduced extractable fractions of Cu and Zn observed by Domínguez et al (1997) in vermicomposted swine sludge, the appreciable decrease in pH during vermicomposting (Gupta and Garg, 2008;Suthar, 2008a;Yadav and Garg, 2009) notwithstanding, makes sense in light of the physicochemical characteristics of vermicomposts; high-cation-exchange capacity and chelating groups (Carrasquero Duran et al, 2006), high surface area (porosity), coupled with a maximum adsorptive capacity (for Cd) at pH 5.0 (Pereira and Arruda, 2003). Wang et al (2013) evaluated the effects of different ratios of phosphoric rock and fly ash on the concentrations of total and extractable metals in sewage sludge during vermicomposting whereby, a reduction in percentage concentration of total metals (Cu, Pb, Cd and As) concentration were obtained and the mean reduction in metal concentration for all five treatments studied was in the order 30.0% (Pb) > 24.6% (Cu) > 20.0% (As) > 13.4% (Cd).…”

Geomaterials as Cost Effective Sorbent to Remove Fluoride from Water

“…42. The pHpzc (point of zero charge) of the adsorbent was estimated using salt addition method as described by [19]. The equilibrium uptake of F − , qe (mg/g), was computed as [20]:…”

Research Analysis of Vermicompost Influence on Bioaccumulation of Heavy Metals in Common Meadow-Grass (Poa Pratensis) / Vermikomposto Įtakos Sunkiųjų Metalų Bioakumuliacijai Pievinėje Miglėje (Poa Pratensis) Tyrimų Analizė

“…Eksperimentas atliktas, remiantis tyrimu, atliktu Vene sueloje, kur buvo tiriama švino (Pb) imobilizacija panau dojant vermikompostą, bei pastarojo įtaką baltajai pupelei (Phaseolus vulgaris) (Carrasquero-Durán et al 2006). 1 pav.…”