1. Development and Actual Utilization of the Electrically Charged Micromist 'Micro EC Mist' System

• Kajima Corp.
• HOCHIKI Corp.

This technology is that generates mist with electric charge given to the surface by a special nozzle, and adsorbs the dust floating on the construction site by spraying the charged mist to precipitate and remove it. By modeling the mechanism of dust removal through indoor experiments, efficient system design is possible. Moreover, we carried out multiple experiments of indoor experiments and performance evaluations at actual construction sites to demonstrate that 30% to 50% of the amount of suspended dust can be removed. This technology is an innovative technology that can remove dust without applying external load with small input energy.

2. Development of a treatment system for heavy-metal contaminated muddy water using a small magnetic separator and regenerating technique of iron-powder”

• Taisei Corp.

This research project provides a remediation technology for huge amount of contaminated muddy water with naturally-occurring heavy metals derives from large-scale construction work such as shield tunnels by compact treatment system. Demonstration test with pilot scale plant verified that iron powder accumulates soluble portion of naturally-occurring arsenic in muddy water and is effectively recovered by a small magnetic separator. Since over 90% of arsenic adsorption capacity of iron powder could be regenerated by chemical immersion with weak acid such as ascorbic acid, the use of virgin material significantly decreased. Reliability, environmental safety, and resource recycling of this treatment system has been highly evaluated.

[Group-2]

1. Waste Recycling System for Shochu distilled spirit – its construction and operation -

• KIRISHIMA SHUZO Co.,ltd.
• Kajima Corporation

Located at Miyazaki prefecture, this project undertakes stable digestion of residues from Shochu distilled spirit production using thermophilic bacteria. Generated biogas is used as renewable energy source as fuel for boilers and gas engines, which has already contributed 80,000 tons of CO2 emission reduction up to now. Final residues from this process are used as fertilizer, which enables the process totally recyclable. Refused sweet potato which cannot be digested by other methods is also recycled in this project that makes significant contribution for the success of sustainable recycling system

Environmental Awards