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).     

Applicability of CDM to civil engineering projects case study on reduction of CO2 emission by port extension

This paper investigates the applicability of CDM to civil engineering projects through a case study on the project to extend Port Samainda in Indonesia. The goal of this project is to improve the physical distribution system of the port so that it can accommodate increasing future demand for the cargo transportation. Based on the project report by JICA (2002), we first outline the predicted demand for the cargo transportation and select possible three options in which a cargo vessel with different capabilities and respective port facilities are assigned. For each option, CO₂ emissions from both cargo and dredging vessels are predicted and compared. It is found that the total CO₂ emission may be reduced significantly by introducing a large-draft vessel and deep navigation channels. This feature becomes more prominent if a traveling distance of the cargo vessels is long enough so that CO₂ emissions from cargo vessels dominates those of dredging vessels. This observation supports the applicability of CDM to civil engineering projects because reduction of the CO₂emission is attained by improving distribution systems through civil engineering works such as extension of the port and the maintenance dredging. Finally, we discuss future problems to be investigated for the practical application of CDM to a civil engineering project. This revised version was published online in August 2006 with corrections to the Cover Date.