The objective of this study was to investigate the changes in soluble sugar accumulation in the main stem, nitrate concentration in Murashige and Skoog (MS) medium, and growth rates of Torenia fournieri ‘Dwarf Blue’ under hypobaric (50 kPa) and atmospheric (100 kPa) conditions with O₂ and CO₂ partial pressures equal to the atmospheric pressure levels. Torenia plants were grown in MS medium at 20% strength without ammonium nitrate by using a reduced pressure plant cultivation system. The plants that were grown at 50 kPa had a greater shoot dry weight and a greater number of floral buds and flowers than those grown at 100 kPa. The soluble sugar concentration in the main apical stem at 50 kPa was higher than that at 100 kPa. The concentration of nitrates in the MS medium at 50 kPa was lower than that at 100 kPa. A reduced pressure of 50 kPa promoted vegetative and reproductive growth in Torenia plants.

The processing of wastewater containing high concentrations of hexavalent chromium, commonly used as a powerful oxidant in many industrial production processes, is not readily available in developing countries. Previously, to develop a simple treatment method for wastewater containing high concentrations of hexavalent chromium, we have been investigated the processing of the artificial wastewater using inexpensive inorganic compounds as treatment agents. As a result, it was confirmed that hexavalent chromium ions were specifically removed as the precipitate containing iron chromate complex and iron chromate from the artificial wastewater by adding ferrous chloride after adding calcium hydroxide. In the present study, to evaluate the practicality of this precipitation treatment method, we verified the processing effect of the aged plating wastewater supplied from a metal plating plant complexly contaminated with high concentrations of hexavalent chromium and several heavy metal ions. As a result, hexavalent chromium, zinc, copper and lead ions in the aged plating wastewater were effectively precipitated and removed by this precipitation method regardless of the presence or absence of agglomeration treatment. Furthermore, no significant re-eluting of hexavalent chromium, zinc, copper and lead ions from the fine powders of the precipitates at pH 3-11 was observed on the re-eluting experiments.