Bioavailability and ecotoxicity of arsenic species in solution culture and soil system: implications to remediation.

In this work, bioavailability and ecotoxicity of arsenite (As(III)) and arsenate (As(V)) species were compared between solution culture and soil system. Firstly, the adsorption of As(III) and As(V) was compared using a number of non-allophanic and allophanic soils. Secondly, the bioavailability and ecotoxicity were examined using germination, phytoavailability, earthworm, and soil microbial activity tests.

Phosphorus-arsenic interactions in variable-charge soils in relation to arsenic mobility and bioavailability.

Phosphorus (P) influences arsenic (As) mobility and bioavailability which depends on the charge components of soil. The objective of this study was to examine P-As interaction in variable-charge allophanic soils in relation to P-induced As mobilization and bioavailability. In this work, the effect of P on arsenate [As(V)] adsorption and desorption was examined using a number of allophanic and non-allophanic soils which vary in their anion adsorption capacity.

Sorption-bioavailability nexus of arsenic and cadmium in variable-charge soils.

In this work, the nexus between sorption and bioavailability of arsenic (As) and cadmium (Cd) as affected by soil type, soil pH, ageing, and mobilizing agents were examined. The adsorption of As and Cd was examined using a number of allophanic and non-allophanic soils which vary in their charge components. The effect of pH and ageing on the bioavailability of As and Cd was examined using spiked soils in a plant growth experiment.

Accumulation of few heavy metals in sewage sludges, soils and plants of Coimbatore, Tamil Nadu (India).

A study was carried out in Coimbatore district of Tamil Nadu (India) to assess the distribution pattern of heavy metals in the soils and plants irrigated with sewage effluent/sludge. About 69 soil samples (surface and subsurface), 65 plant samples as well as 34-sewage sludge samples were collected from various tehsils of Coimbatore. Six tehsils in Coimbatore have been identified and categorized into two groups--Class I City (densely populated tehsils) and Class II city (thinly populated tehsils).

Dynamics of lead (Pb) in different soil conditions.

Four soil samples were collected from various locations having wider range of pH and EC for incubation experiment. These soil samples were added with Pb (NO3)2 salts, and samples were taken on 1st, 35th, 45thand 60th day. Soils samples were fractioned by sequential extraction to estimate the concentration of lead in different fractions viz, water soluble, exchangeable +adsorbed, organic, carbonate and residual fraction.