Effects of EDTA on adsorption of Cd(II) and Pb(II) by soil minerals in low-permeability layers: batch experiments and microscopic characterization.

Ethylenediaminetetraacetic acid (EDTA) can serve as a washing agent in the remediation of low-permeability layers contaminated by heavy metals (HMs). Therefore, batch adsorption experiments, where pure quartz (SM1) and mineral mixtures (SM2) were used as typical soil minerals (SMs) in low-permeability layers, were implemented to explore the effects of different EDTA concentrations, pH, and exogenous chemicals on the HM-SM-EDTA adsorption system. As the EDTA concentration increased, it gradually cut down the maximum Cd adsorption capacities of SM1 and SM2 from approximately 135 to 55 mg/kg and 2660 to 1453 mg/kg; and the maximum Pb adsorption capacities of SM1 and SM2 were reduced from 660 to 306 mg/kg and 19,677 to 19,262 mg/kg, respectively.

Mobilisation of bacteria in a fine-grained residual soil by electrophoresis.

An investigation of electrokinetic bacterial mobilisation in a residual soil from gneiss is presented here. The experimental program aimed at assessing the efficacy of electrophoresis against the electro-osmotic flow to transport endospores of Bacillus subtilis LBBMA 155 and nitrogen-starved cells of Pseudomonas sp. LBBMA 81.