Abstract:

The entrance of Tianmushan Tunnel is adjacent to the national scenic area of “Xin’an RiverFuchun RiverQiandao Lake”. The protection of the safety of local ecological environment and drinking water is very important. As a result, the characteristics of construction wastewater of Tinmushan Tunnel are analyzed; the results show that the suspended solids (SS) and power of hydrogen (pH) in wastewater exceed the limit. The heavy metals related to the engineering geology are detected in the wastewater, which do not exceed the limit except mercury (Hg) and nickel (Ni) in some of water samples. The wastewater treatment method of “primary setting + coagulation + sediment + filtration” is adopted. The suspended solids with large particle size can be removed by primary setting process; and the fine particulate matter and the heavy metals can be removed by coagulation and sediment process. The application results show that the quality of construction wastewater after treatment can meet relevant requirements; meanwhile, the treatment cost of the wastewater per cubic meter is RMB 0.51, so as to show beffer economical benefit.

Key words: Tianmushan Tunnel, tunnel construction wastewater, wastewater treatment, heavy metal