Events such as the ‘Benzene pollution incident,’ which turned Songhua River in Northeast China into a river of death, the ‘Nakdong River phenol accident,’ which almost made Doosan Electronics close its business and ‘Cheonggye Restoration Project,’ have increased people’s demand for safe water and a fresh living environment. Polluted/waste water processing facilities necessary to meet the demand are also attracting public attention.


However, polluted/waste water processing facilities themselves are recognized as noxious. In addition, it’s difficult to expand previous facilities or to construct new ones because of excessive construction costs. The maintenance costs are also high because of high labor costs and excessive energy consumption. Under these circumstances, the increasing necessity is to develop technology improving existing facilities, to make them environmentally friendly, welcome by local residents, less expensive to operate, and more compatible as a good neighbor.


The recent trend for improvement includes the following:
· covering previous waste water processing facilities with landfill to construct parks or sports centers on top,

· using methane gas generated from waste water processing facilities as an energy source, and

· making a natural stream by installing a biotechnological processing facility in the discharging end of waste water processing facilities.

These improvements are made to provide local residents with a site for environmentally friendly education, as well as with a comfortable place for recreation or leisure.


Various technologies are being developed to realize the changes. Some of the core technologies include a natural purification system that uses sand, pebbles and water plants to process waste water; construction of ecological streams; construction of artificial wetlands; installation of artificial floating islands; and improvement in the purification ability of water plants.


During the past 5 years (2001~2005), the overall number of patent applications related to biological processing technology of polluted/waste water gradually decreased from 359 in 2001 to 231 in 2005. However, number related to technology using animal/plants/natural resources has continuously increased from 19 in 2001 to 26 in 2005. This shows that the trend of related technology development is more sensitive to environmentally friendly demands.


To look specifically into technology using animal/plants/natural resources, applications were mostly made for technology installing purification facilities in river or lake banks. Also, many applications were related to installation of artificial floating islands, construction of wetlands and improvement to the purification ability of water plants/animals. A variety of plants/animals was designated as ones that purify water, including shellfish, reed, water hyacinth, cattail, waterweed, and lotus flower.


Personal applications were dominant until 2004. In 2005, the number of corporation applications was 1.5 times larger than the number of personal ones, indicating that companies are actively developing environmentally friendly polluted/waste water processing facilities.


Given the increased global alertness towards environmental issues and improvement of the standard of life in Korea, the domestic technology for restoring and purifying polluted/waste water using animal/plants/natural resources is expected to develop more actively in the future.