Three samples of terra rossa were shown to be efficient adsorbents of phosphate [P(V)] from wastewater and removed 29.9–32.6% of P(V). The total iron content in terra rossa was the key factor which determined the P(V) removal from wastewater. The original samples of terra rossa were effective support materials for the immobilization of metabolically active P(V)-accumulating bacteria Acinetobacter junii (0.56–2.47×1010 CFU g–1). The removal of oxalate-extractable iron from original sample of terra rossa increased the number of immobilized bacteria to 1.34×10–11 CFU g–1, which is the largest number of immobilized bacteria reported in the literature so far. In reactors containing the A. junii and terra rossa P(V) was removed from wastewater by simultaneous adsorption onto terra rossa and accumulation inside bacterial cells, resulting in 40.5–62.5% of P(V) removal. Terra rossa is a promising substrate for biological P(V) removal from wastewater, acting both as adsorbent of P(V) and carrier of P(V)-accumulating bacteria.

Sorption and desorption of cyanazine with three Mississippi Delta soils (two silt loams and one silty clay) were studied under laboratory conditions. Cyanazine sorption calculated using the Freundlich equation was greatest for the Sharkey silty clay soil. Partition coefficients (K d values) for cyanazine sorption ranged from 1.67 to 1.82, 1.92 to 2.15, and 3.65 to 3.96 ml g−1 for the Bosket silt loam, Dubbs silt loam, and Sharkey silty clay soils, respectively. Differences in sorption and K d values were attributed to clay content. At a given initial cyanazine concentration, cyanazine was desorbed more readily from the silt loam soils than from the Sharkey clay after the first 4-h desorption cycle. Desorption from the Sharkey clay continued for a longer period than that from the silt loam soils, with up to 6% cyanazine desorption from the Sharkey clay after a 16-h desorption cycle compared with 0% for the silt loam soils. Cyanazine losses increased with decreasing clay content, Dubbs = Bosket > Sharkey. This implies a potential relationship between cyanazine desorption and surface runoff losses of cyanazine.

The sorption isotherm for excised embryonic axes of recalcitrant (i.e. desiccation-sensitive) Quercus robur L. acorns was determined to find the relation between moisture content and water potential. Subsequently, physiological studies on the effect of desiccating the axes to a range of water potentials were undertaken. The respiratory capacity declined steeply after short exposure to water potentials from −5 to −30 MPa. The leachate conductivity increased significantly after exposure to −5 MPa and rose steeply after exposure to between −12 and −40 MPa. Axes were equilibrated at different relative humidities and the proline content showed a 15-fold increase with a peak value at −10 MPa. It was concluded that the critical water potential for initiation of damage was −5 MPa, and that axes accumulated proline as a response to desiccation stress. The embryonic axes from Q. robur behave more like typical vegetative tissue of angiosperms than like orthodox seeds.

Seed desiccation sensitivity was studied in nine species of the genus Coffeaby measuring seed viability after equilibration over various saturated salt solutions. A quantal response model based on the logistic distribution was developed in order to describe the typical S-shaped patterns observed. The closeness of fit of the desiccation sensitivity model was shown, and the assumption that seed desiccation sensitivity follows a continuous distribution within species was verified. For each species, the water content at which 50% of initial viability was reached, WC50, and a specific parameter describing the intra-specific variability, β, were calculated using a non-linear regression. A simplified water sorption model was developed which allowed easy calculation of water activity and water potential corresponding to WC50 (aw50 and Ψ50) for relative humidities ranging between 10 and 100%. Distribution of WC50and Ψ50 (or aw50) in the genus Coffea was homogeneous within the following intervals: from 0.05 to 0.38 g H2O.g−1dw for WC50 and from −168 to −11 MPa for Ψ50. Different classifications of the coffee species studied as regards to their desiccation sensitivity were obtained depending on whether WC50 or Ψ50was used for classification. The continuum for desiccation sensitivity observed within the nine species studied confirmed that coffee is an appropriate material for studying desiccation sensitivity.