Removal of Pb(II) from water using keratin colloidal solution obtained from wool

The aim of this study is to investigate the use of keratin colloidal solution, which was obtained from wool, for the removal of Pb(II) from water. The addition of keratin colloidal solution (15 g L^?1, 0.30 mL) to a Pb(II) solution (1.0 mM, 0.90 mL, pH 5.0) resulted in the formation and precipitation of a Pb–keratin aggregate. Measurement of the Pb(II) and protein concentrations in the supernatant solution revealed that 88 and 99 % of the Pb(II) and keratin protein were removed from the solution, respectively. The maximum Pb(II) uptake capacity of keratin in the colloidal solution was 43.3 mg g^?1. In addition, the Pb–keratin aggregate was easily decomposed via the addition of nitric acid, which enabled the recovery of Pb(II). However, aggregation did not occur in solutions with Pb(II) concentrations below 0.10 mM. Therefore, we used a keratin colloidal solution encapsulated in a dialysis cellulose tube to remove Pb(II) from 0.10 mM solutions, which enabled the removal of 95 % of the Pb(II). From these results, we conclude that keratin colloidal solution is useful for the treatment of water polluted with Pb(II).     

The Impact of Sika Deer on Vegetation in Japan: Setting Management Priorities on a National Scale

Irreversible shifts in ecosystems caused by large herbivores are becoming widespread around the world. We analyzed data derived from the 2009–2010 Sika Deer Impact Survey, which assessed the geographical distribution of deer impacts on vegetation through a questionnaire, on a scale of 5-km grid-cells. Our aim was to identify areas facing irreversible ecosystem shifts caused by deer overpopulation and in need of management prioritization. Our results demonstrated that the areas with heavy impacts on vegetation were widely distributed across Japan from north to south and from the coastal to the alpine areas. Grid-cells with heavy impacts are especially expanding in the southwestern part of the Pacific side of Japan. The intensity of deer impacts was explained by four factors: (1) the number of 5-km grid-cells with sika deer in neighboring 5 km-grid-cells in 1978 and 2003, (2) the year sika deer were first recorded in a grid-cell, (3) the number of months in which maximum snow depth exceeded 50 cm, and (4) the proportion of urban areas in a particular grid-cell. Based on our model, areas with long-persistent deer populations, short snow periods, and fewer urban areas were predicted to be the most vulnerable to deer impact. Although many areas matching these criteria already have heavy deer impact, there are some areas that remain only slightly impacted. These areas may need to be designated as having high management priority because of the possibility of a rapid intensification of deer impact.